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LIST  OF  CONTRIBUTORS. 


ANDREWS,  R.R.,  A.M.,  D.D.S.,  F.R.M.S.; 

BURCHARD,  HENRY  H.,  M.  D.,  D.D.S., 

CASE,  CALVIN    S.,  M.  D..    D.  D.  S.  ; 

CLAPP,  DWIGHT   M.,  D.M.D.; 

CRYER,   M.H.,  M.D.,  D.  D.  S. ; 

DARBY,   EDWIN    T.,  M.  D  ,    D.  D.S.; 

GODDARD.  C.  L.,  D.  D.  S  ; 

GUILFORD,  S.  H.,  A.M.,  D.  D.S.,  Ph.D.; 

HEAD,  JOSEPH    B.,  M.  D.,   D.  D.  S.  ; 

JACK,  LOUIS,  D.  D.S. ; 

KIRK,  EDWARD   C,   D  D.  S  ; 

NOYES,  FREDERICK   B.,  B.  A  ,  D.D.S.; 

OTTOFY.  LOUIS,  D   D.  S.  ; 

PEIRCE.  C.  N..  D.D.S.; 

THOMAS,  J.  D.,   D.  D.  S. ; 

THOMPSON,  ALTON  HOWARD,  D.D.S.; 

TRUMAN,  JAMES,  D.  D.  S. 


THE 


AMERICAN  TEXT-BOOK 


OF 


OPERATIVE  DENTISTRY, 


IN  CONTRIBUTIONS  BY  EMINENT  AUTHORITIES. 


EDITED  BY 


EDWARD   C.  KIRK,  D.D.S., 

Professor  of  Clinical  Dentistry  in  the  University  of  Pennsylvania,  Philadelphia; 
Editor  of  "  The  Dental  Cosmos." 


SECOND  EDITION,  BE  VISED  AND  ENLARGED. 


ILLUSTRATED  WITH    897  ENGRAVINGS. 


LEA   BROTHERS   &   CO., 

PHILADELPHIA    AND    XEW    YORK. 

1900. 


^7-  ^^'  ^^ 


Entered  according  to  Act  of  Congress  in  the  year  1900,  by 

LEA   BROTHERS   &  CO., 

in  the  Office  of  the  Librarian  of  Congress,  at  Washington.     All  rights  reserved. 


Kf^ 


l^VJ 


WESTCOTT    &    THOMSON, 
ELEGTROTVPERS,     PHILADA. 


WITH   THE  CONSENT  OF  THE  CONTRIBUTORS 

THIS  BOOK   IS  DEDICATED  TO 

JAMES    TRUMAN,   D.  D.  S., 

THE    CHARACTERISTIC  OF  WHOSE    LONG    PROFESSIONAL    CAREER    HAS 

BEEN  THE  INCULCATION  OF  THE  PRINCIPLES  UPON 

WHICH   THE  WORK  IS   BASED. 


PREFACE  TO  THE  SECOND  EDITION. 


The  preparation  of  a  text-book  upon  Operative  Dentistry,  com- 
posite in  its  authorship,  was  regarded  by  the  Editor  as  a  tentative 
experiment  the  vahie  of  which  could  only  be  determined  by  the  test 
of  practical  experience.  The  cordial  reception  of  the  work  by  dental 
teachers  and  its  extensive  use  by  students  afford  encouraging  evidence 
that  a  work  so  planned  and  executed  was  needed. 

The  increasing  tendency  to  specialization  in  dentistry  has  rendered 
still  more  remote  the  possibility  of  adequately  presenting  the  entire 
field  of  operative  dentistry  through  the  medium  of  a  single  volume 
of  individual  authorship;  hence  the  composite  method,  whereby  the 
several  departments  are  set  forth  by  experts  in  each  case,  seems  likely 
to  afford  the  most  generally  satisfactory  result. 

The  Editor  is  fully  aware  of  the  importance  which  attaches  to  the 
work  of  harmoniziug  the  treatment  of  the  individual  subjects  and  of 
so  coordinating  them  that  conflicting  views  shall  not  confront  the  stu- 
dent, and  thus  interfere  with  his  advancement  into  an  untrodden  field  ; 
a  recognition  of  this  factor  has  served  as  a  guidiug  motive  both  in  the 
preparation  and  the  revision  of  the  work. 

Specialization  in  operative  dentistry  has  not  reached  the  point  where 
it  may  be  deemed  best  to  limit  the  field  of  text-book  treatment  to  its 
technical  procedures  and  relegate  the  allied  subjects  to  separate  vol- 
umes ;  hence  the  chapter  upon  Dental  Embryology  has  been  retained 
and  the  subject  extended  to  include  so  much  of  Dental  Histology  as 
bears  directly  upon  operative  procedures,  and  it  is  anticipated  that  the 
admirable  chapter  by  Professor  Xoyes  will  prove  an  acceptable  addi- 
tion. The  chapter  upon  Porcelain  Inlay  work  has  been  rewritten  in 
the  light  of  the  most  recent  developments  of  that  rapidly  progressing 
field  of  study.  The  formal  treatment  of  Asepsis  and  Antisepsis,  which 
is  the  basis  of  an  added  chapter  by  Professor  Truman,  needs  no 
apology;  the  importance  of  a  thorough  appreciation  of  the  role  played 
by  oral  bacteria  in  the  causation  and  transmission  of  disease  is  self- 
evident,  as  a  recognition  of  the  bacterial  factor  in  oral  conditious  has 
become  a  nine  qua  non  of  successful  dental  practice.  In  the  jireseut 
edition  the  text  has  been  thoroughlv  revised,  a  larg-e  number  of  illus- 

7 


8  PREFACE  TO   THE  SECOND  EDITION. 

trations  and  much  now  matter  have  been  added,  and  tlie  treatment  of 
the  wliole  sul)je('t  broiiglit  into  harmony  with  the  latest  development 
of  thought   in   the   fiehl   wliieh   it  covers. 

The  Editor  desires  to  thank  his  colleagues  in  the  educational  Held 
for  many  helpful  (criticisms  and  suggestions  received  since  the  first 
appearance  of  the  work.  These  have  been  largely  utilized  in  its 
revision.  His  thanks  are  also  due  to  the  several  contributors  for  their 
generous  cooperation  and  acquiescence  in  such  alterations  as  have 
seemed  desirable  for  the  betterment  of  the  work. 

The  death  of  Dr.  H.  H.  Burchard,  who  was  so  closely  associated 

with  this  work   both  as  a  contributor  and   as  a   helj)ful  guide  in  the 

preparation  of  the  first  edition  for  the  ])ress,  creates  a  vacancy  in  the 

ranks  of  American   dental  writers  which   will  be  generally  deplored, 

and  especially  so  by  his  collaborators  in  the  present  work.     Ill  health 

made    it    impossible    for    him    to    take    part    in    the   present    revision, 

but    his    contributions    being    based    upon    sound    scientific    principles 

needed  but  minor  amendments,  which   the  Editor  has   endeavored  to 

supply  in  the  spirit  of  the  author. 

E.  C.  K. 

October,  1900. 


LIST  OF  CONTRIBUTORS. 


R.  R.  ANDREWS,  A.  M.,  D.  D.  S.,  F.  R.  M.  S., 
Cambridge,  Mass. 

HENRY  H.  BURCHARD,  M.  D.,  D.  D.  S., 

Late  Special  Let-turer  on  Dental  Pathology  and  Therapeutics,  Philadelphia  Dental 
College,  Philadelphia. 

CALVIN  S.  CASE,  M.  D.,   D.  D.  S., 

Professor  of  Orthodontia,  Chicago  College  of  Dental  Surgery,  Chicago,  111. 

DWIGHT  M.  CLAPP,  D.  M.  D., 

Clinical  Lecturer  on  Operative  Dentistry,  Dental  Department,  Harvard  University, 
Boston,  Mass. 

M.  H.  CRYER,  M.  D.,  D.  D.  S., 

Assistant  Professor  of  Oral  Surgery  in  the  University  of  Pennsylvania,  Philadelphia. 

EDWIN  T.  DARBY,  M.  D.,  D.  D.  S., 

Professor  of  Operative  Dentistry  and  Dental  Histology  in  the  University  of  Penn- 
sylvania, Philadelphia. 

C.  L.  GODDARD,   D.  D.  S., 

Professor   of  Orthodontia,    University   of  California,    College  of  Dentistry,  San 
Francisco,  Cal. 

S.  H.  GUILFORD,  A.  M.,  D.  D.  S.,  Ph.D., 

Professor  of  Operative  and  Prosthetic  Dentistry  and  Dean  of  the  Philadelphia 
Dental  College,  Philadelphia. 

JOSEPH  B.  HEAD,  D.  D.  S.,  M.  D., 

Philadelphia. 

LOUIS  JACK,  D.  D.  S., 

Philadelphia. 


10  LIST  OF  CONTRIBUTORS. 

EDWARD  C.  KIRK,  D.  D.  S., 

Professor  (if  Clinical  Dentistry  in  the  University  of  Pennsylvania,  Philad(.'l|iliia, 
and  Dean  of  the  Department  of  Dentistry. 

FREDERICK  B.  XOYES,  B.  A.,  D.  I).  S., 

Professor  of  Dental  Ilistoiojry  in  the  Northwestern  University  Dental  Sehool, 
Cliicago,   111. 

LOUIS  OTTOFY,  D.  D.  8., 

Professor  of  Clinical  Therapeutics,  Chicago  College  of  Dental  Surgery,  Chicago; 
formerly  Dean  and  Professor  of  Dental  Pathology,  American  College  of  Dental 
Surgery,  Chicago,  111. 

C.  N.  PEIRCE,   D.  D.  S., 

Professor  of  Dental  Physiology,  Dental  Pathology,  and  Operative  Dentistry,  and 
Dean  of  the  Pennsylvania  College  of   Dental  Surgery,   Philadelphia. 

J.  D.  THOMAS,  D.  D.  S., 

Lecturer  on  Nitrous  Oxid,  Department  of  Dentistry,  University  of  Pennsylvania, 
Philadelphia. 

ALTON  HOWARD  THOMPSON,  D.  D.  S., 

Professor  of  Dental  Anatomy,  Kansas  City  Dental  College,  Kansas  City,  Mo. 

JAMES  TRUMAN,   D.  D.  S., 

Professor  of  Dental  Pathology,  Tlierapeutics,  and  Materia  Medica  in  the  Uni- 
versity of  Pennsylvania,  Philadelphia. 


CONTENTS. 


CHAPTER  I. 

PAGE 

MACROSCOPIC  ANATOMY  OF  THE  HUMAN  TEETH 17 

By  Altox  Howard  Thompsox,  D.  D.  S. 


CHAPTER  II. 

THE  EMBRYOLOGY  OF  THE  DENTAL  TISSUES 53 

By  R.  R.  Andrews,  A.  M.,  D.  D.  S.,  F.  R.  M.  S. 

CHAPTER   III. 

DENTAL  HISTOLOGY  WITH  REFERENCE  TO  OPERATIVE  DEN- 
TISTRY         93 

By  Frederick  B.  Noyes,  B.  A.,  D.  D.  S. 

CHAPTER  IV. 

ANTISEPSIS  IN  DENTISTRY 157 

By  James  Trumax,  D.  D.  S. 

CHAPTER   V. 

THE  EXAMINATION  OF  TEETH  PRELIMINARY  TO  OPERATION- 
METHODS,  INSTRUMENTS,  APPLIANCES— RECORDING  RESULTS, 

ETC 173 

By  Louis  Jack,  D.  D.  S. 

CHAPTER  VI. 

PRELIMINARY  PREPARATION  OF  THE  TEETH— REMOVAL  OF 
DEPOSITS  AND  CLEANING  OF  THE  TEETH— WEDGING— OTHER 
METHODS  OF  SECURING  SEPARATIONS— EXPOSURE  OF  CERVI- 
CAL MARGINS  BY  SLOW  PRESSURE,  ETC 181 

By  Louis  Jack,  D.  D.  S. 

11 


12  CONTEXTS. 

CHAPTER   VII. 

PAGE 

PRELIMINARY  PREPARATION  OF  CAVITIES— TREATMENT  OF  HY- 
PERSENSITIVE DENTIN  BY  SEDATIVES,  OBTUNDENTS,  LOCAL 
AND  GENERAL  ANESTHETICS— STERILIZATION,  WITH  A  BRIEF 
CONSIDERATION  OF  THE  PHYSIOLOGICAL  AND  THERAPEUTIC 
ACTION  OF  THE  MEDICAMENTS  USED 189 

By  Louis  Jack,  D.  I).  S. 

CHAPTP:R   VIII. 

PREPARATION  OF  CAVITIES— OPENING  THE  CAVITY— REMOVING 
THE  DECAY- SHAPING  THE  CAVITY— CLASSIFICATION  OF 
CAVITIES 215 

By  S.  H.  Guilford,  A.  M.,  D.  D.  S.,  Ph.  D. 

CHAPTER   IX. 

EXCLUSION  OF  MOISTURE— EJECTION  OF  THE  SALIVA— APPLICA- 
TION OF  THE  DAM  IN  SIMPLE  CASES,  AND  IN  SPECIAL  CASES 
PRESENTING  DIFFICULT  COMPLICATIONS— NAPKINS  AND 
OTHER  METHODS   FOR  SECURING   DRYNESS 239 

By  Louis  Jack,  D.  D.  S. 

CHAPTER   X. 

THE  SELECTION  OF  FILLING  MATERIALS  WITH  REFERENCE  TO 
CHARACTER  OF  TOOTH  STRUCTURE,  VARIOUS  ORAL  CONDI- 
TIONS AND  LOCATION,  DEPTH  OF  CAVITY  AND  PROXIMITY 
OF  THE  PULP— CAVITY  LINING,  W^ITH  ITS  PURPOSES 249 

By  Louis  Jack,  D.  D.  S. 

CHAPTER  XL 

TREATMENT  OF  FILLINGS  WITH  RESPECT  TO  CONTOUR,  AND  THE 
RELATION  OF  CONTOUR  TO  PRESERVATION  OF  THE  INTEG- 
RITY OF  APPROXIMAL  SURFACES 261 

By  S.  H.  Guilford,  A.  M.,  D.  D.  S.,  Ph.  D. 

CHAPTER  XIL 

THE  OPERATION   OF   FILLING   CAVITIES   WITH   METALLIC  FOILS 

AND  THEIR  SEVERAL  MODIFICATIONS 267 

By  Edwin  T.  Darby,  D.  D.  S.,  M.  D. 


CONTENTS.  13 

CHAPTER   XIII. 

;  PAGE 

PLASTIC    FILLING    MATERIALS— THEIR    PROPERTIES,   USES,  AND 

MANIPULATION 305 

By  Henry  H.  Burchakd,  M.  D.,  D.  D.  S. 

CHAPTER   XIV. 

COMBINATION  FILLINGS 345 

By  DwiGHT  M.  Clapp,  D.  M.  D. 

CHAPTER   XV. 

RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS 369 

By  Joseph  Head,  M.  D.,  D.  D.  S. 

CHAPTER   XVI. 

THE  CONSERVATIVE   TREATMENT   OF  THE    DENTAL    PULP— DE- 
VITALIZATION AND  EXTIRPATION  OF  THE  PULP 401 

By  Louis  Jack,  D.  I).  S. 

CHAPTER   XVII. 

THE   TREATMENT  AND  FILLING  OF  ROOT  CANALS 429 

By'  Henry  H,  Burchard,  M.  D,,  D.  D.  S. 

CHAPTER    XVIII. 

DENTO- ALVEOLAR   ABSCESS •    479 

By  Henry  H.  Burchard,  M  D.,  D.  D.  S. 

CHAPTER   XIX. 

PYORRHEA  ALVEOLARIS 505 

By  C.  X.  Peirce,  D.  D.  S. 

CHAPTER    XX. 

DISCOLORED  TEETH  AND  THEIR  TREATMENT 535 

By  Edward  C.  Kirk,  D.  D.  S. 

CHAPTER   XXI. 

EXTRACTION  OF  TEETH 561 

By  M.  H.  Cryer,  M.  D.,  D.  D.  S. 


14  COiW  TENTS. 

CHAPTEK   XXL  (Continued). 

EXTKACTION  OF  TEETH  UNDER  NITROUS  OXID  ANESTHESIA    .    .    629 

By  J.  D.  Thomas,  D.  D.  S. 

CHAPTER   XXI.  (Concluded). 

LOCAL  ANESTHETICS  AND  TOOTH  EXTRACTION 639 

By  Henry  II.  Bukchakd,  M.  D.,  D.  D.  S. 

CHAPTER   XXn. 

PLANTATION  OF  TEETH 645 

By  Louis  Ottopy,  D.  D.  S. 

CHAPTER   XXin. 

MANAGEMENT  OF  THE  DECIDUOUS  TEETH 663 

By  Clark  L.  Goddard,  A.  M.,  D.  D.  S. 

CHAPTER   XXIV. 

ORTHODONTIA  EXCLUSIVELY  AS  AN  OPERATIVE  PROCEDURE  .    .    683 
By  Clark  L.  Goddard,  A.  M.,  D.  D.  S. 

CHAPTER   XXV. 

THE    DEVELOPMENT  OF  ESTHETIC   FACIAL  CONTOURS 805 

By  Calvin  S.  Case,  M.  D.,  D.  D.  S. 

INDEX 843 


INTRODUCTORY. 


A  STUDY  of  the  advances  which  have  of  recent  years  taken  place  in 
the  tield  of  Operative  Dentistry  will  reveal,  besides  the  important  addi- 
tions to  our  knov.'ledge  in  the  shape  of  novel  methods  and  improved 
technique,  a  vastly  more  important  advance  manifested  in  a  better  and 
more  general  understanding  of  scientitic  principles,  and  the  application 
of  dental  science  to  dental  art,  resulting  in  a  more  rational  practice. 
Especially  is  this  true  in  regard  to  the  etiology  of  dental  and  oral 
pathological  conditions,  and  the  rationale  of  the  modes  of  treatment 
indicated  for  the  morbid  states  constantly  confronting  the  dental 
practitioner. 

The  modifications  in  surgical  methods  and  the  greatly  improved 
results  which  are  the  outgrowth  of  modern  scientific  studies  in  bacterial 
pathology,  ^\hilc  they  have  made  a  considerable  impress  upon  dental 
operative  methods,  have  not,  however,  received  that  universal  practical 
acceptance  among  dental  operators  which  their  immense  importance 
demands.  There  is  no  field  of  special  surgery  in  which  the  import- 
ance of  exact  knowledge  with  respect  to  aseptic  and  antiseptic  treat- 
ment is  more  marked  than  in  the  practice  of  dentistry.  The  dental 
operator  is  continually  confronted  with  septic  conditions,  so  that  pre- 
cise knowledge  of  their  origin,  causes,  phenomena,  and  treatment  are 
essentials  to  the  legitimate  practice  of  the  profession. 

The  performance  of  any  operation,  and  especially  those  which  arc 
classified  as  capital,  with  unclean  hands  or  infected  instruments  would 
in  the  present  stage  of  surgical  art  be  regarded  as  criminal  malpractice. 
It  should  be  so  considered  in  dentistry.  The  loss  of  a  patient's  life  as 
the  result  of  surgical  septic  infection  is  no  longer  permissible.  Lack 
of  antiseptic  ])recautions  in  certain  dental  operations  may  directly  lead 
to  and  as  a  matter  of  fact  has  been  the  cause  of  fatal  results.  It  has 
been  shown  conclusively '  that  a  large  variety  of  pathogenic  micro- 
organisms are  almost  constant  inhabitants  of  the  oral  cavity.  In  addi- 
tion to  the  numerous  forms  whicli  bring  about  an  acid  reaction,  there 
are  many  specified  organisms  which  produce  in  inoculated  animals 
pyemia  and  septicemia  in  their  several  clinical  classes.  But  while  the 
dental  practitioner  is  not  often  called  upon  to  face  the  issues  of  life 

^  W.  D.  Miller,  Dental  Cosmos,  November,  1891. 

15 


16  INTRODUCTORY. 

and  (Icatli  in  the  coui-sc  of"  his  work,  his  responsibilities  as  related  to 
the  issues  with  which  he  does  deal  demand  of  him  the  same  care  and 
thoroughness  in  order  to  attain  the  eharaeter  of  result  which  the  pos- 
sibilities of  modern  dentistry  reipiire  of  him.  In  the  following  pages 
the  importance  of  asepsis  and  antisej)sis  in  dental  operations  is  con- 
stantly  impressed  upon  the  mind  of  the  student. 

By  the  term  asej)sis  is  specifically  meant  the  condition  under  which 
are  excluded  those  influences  or  causes  which  induce  infection  by  patho- 
genic micro-organisms ;  when  a  tissue  or  surface  has  been  rendered 
germ-free  it  is  said  to  be  in  an  aseptic  condition.  By  antmepsis  is 
meant  the  means  by  which  the  septic  state  is  combated  or  the  aseptic 
state  is  attained. 

Under  the  aseptic  condition  repair  of  tissues  takes  place  normally 
without  interference,  wounds  and  injuries  heal  w^ith  a  minimum  of  dis- 
turbance, and  the  inflammatory  concomitant  is  of  the  simple  traumatic 
type,  without  suppuration  or  tendency  to  diffusion. 

The  aseptic  state,  in  many  operations  in  the  mouth,  is  not  readily 
attainable  and  cannot  be  maintained  for  any  length  of  time  ;  but  in  all 
operations  which  involve  the  pulp  and  pulp  chamber,  as  well  as  the 
periapical  region  through  the  pulp  canals  of  teeth,  strict  aseptic  con- 
ditions, as  regards  external  infection,  are  perfectly  attainable  through 
exclusion  of  the  oral  secretions  by  means  of  rubber  dam,  the  use  of 
suitable  disinfectants,  and  sterilized  instruments.  It  is  the  class  of 
operations  here  alluded  to  which  are  most  prolific  of  disturbance  from 
infective  inflammations  caused  by  ignorant  or  careless  mani))ulation. 

The  time  is  at  hand,  if  indeed  it  has  not  already  arrived,  when  puru- 
lent inflammations  following  dental  treatment  wnll  be  regarded  with 
the,  same  condemnation  of  the  dentist  as  of  the  general  surgeon.  The 
operative  section  of  this  w^ork  is  written  in  full  recognition  of  the  prin- 
ciples here  indicated. 


OPERATIVE  DENTISTRY. 


CHAPTER   I. 

MACROSCOPIC  ANATOMY  OF  THE   HUMAN  TEETH, 

By  Alton  Howard  Thompson,  D.  D,  S. 


1.  Definition, — The  teeth  may  be  properly  defined  as  hard,  cal- 
careous bodies  situated  in  that  portion  of  the  alimentary  canal  near  the 
anterior  or  oral  extremity.  In  man  they  are  confined  to  the  oral  cavity 
and  are  supported  by  the  maxillary  bones  only.  In  the  lower  verte- 
brates they  may  be  scattered  over  all  of  the  bones  and  cartilages  sur- 
rounding the  mouth. 

2,  Function. — The  main  function  of  the  teeth  is  the  mechanical  sub- 
division of  substances  used  for  food,  preparatory  to  their  digestion  ;  these 
orirans  therefore  beiona:  to  the  alimentarv  svstem.  The  elements  of 
their  function  are  prehension,  incising,  crushing,  mastication,  and  insali- 
vation.  For  the  performance  of  these  various  offices,  different  forms 
of  teeth  are  found  in  the  denture  of  man.  In  lower  animals  food-habit 
induces  the  evolution  of  many  various  and  extreme  forms  of  the  teeth. 

The  secondary  offices  of  the  teeth  in  man  are  as  adjuncts  in  vocal- 
ization and  articulate  speech ;  they  also  bear  an  esthetic  relation  to  the 
mouth  and  face. 

Fig.  1. 


Il-if  I    I 

The  formation  of  single  teeth  from  the  single  cone  and  its  repetition  in  complex  teeth. 

3,  Mechanical  Design. — All  tooth  forms  are  evolved  by  modification 
from  a  simple  cone,  which  is  the  primitive,  typal  form.  The  teeth  of  fishes 
and  reptiles  are  but  simple  cones,  and  those  of  higher  mammals  are 
modifications  of  the  sinsfle  cone  or  combinations  of  two  or  more  cones 

2  17 


18  MACROSCOPIC  ANATOMY   OF   Till':  HUMAN   TEETH. 

fused  together.  Thus  iu  uinu  the  incisors  arc  formed  oi'  a  sin<2;le  cone,  the 
truncated  apex  of  which  is  compressed  to  form  the  wide  cutting-  edge  (Fig. 
1,  (f).  The  canine  or  cuspid  is  a  single  cone,  the  apex  of  which  is  com- 
pressed into  a  trihech'al  point,  or  pointed  pyramid  (b).  The  bicuspids 
are  composed  of  two  coiu^s  fused  together,  the  forms  of  the  cones  being 
(piitc  distinct  the  entire  k'ugth  of  the  tooth,  as  iu  the  upper  bicuspids  (c). 
The  typal  upper  molar  is  formed  by  the  addition  of  the  third  cone  to 
the  l)icuspid  form,  as  ])lainly  noticed  in  the  three  roots  and  the  primitive 
three  cusps  ((/).  The  usual  ([uadrieuspid  form  is  made  by  the  addition 
of  a  cingule.  The  lower  molar  consists  of  four  cones,  which  may  be 
plainly  distinguished  by  an  analysis  of  its  elements  {e).  Each  cone  in 
the  structure  of  a  tooth  is  surmounted  by  a  cusp  or  tubercle.  Extra  cusps 
above  the  number  of  primary  cones  are  but  cingules  or  undeveloped  cusps. 

In  the  genesis  of  tooth  forms,  therefore,  the  complex  teeth,  as  the 
bicuspids  and  molars,  are  formed  by  the  repetition  and  addition  of  cones 
and  their  accompanying  cusps,  both  laterally  and  longitudinally  of  the  jaw. 

4.  The  Dental  Arch. — The  teeth  of  man  are  arranged  around  the 
margins   of  the  upper  and  lower  jaws  in  close   contact,  and  have  no 


Fig.  2. 


Square.  Rounded  Square.  Rounded.  Rounded  V. 

The  main  types  of  the  dental  arch. 

interspaces  between  them.  The  basal  arch  is  a  graceful  parabolic  curve, 
with  some  variations  which  lead  from  the  round  arch  to  the  incomplete 
parallelogram  or  even  to  a  w^ell-defined  V  shape.  These  variations  may 
be  classified  as  follows : 

First:  The  square  arch  (Fig.  2,  a).  This  is  found  usually  in 
persons  of  strong  osseous  organization,  of  Scotch  or  Irish  descent — i.  e. 
of  Gaelic  extraction — and  is  probably  derived  in  the  first  instance  from 
a  dolichocephalic  people.  The  squareness  is  more  or  less  dependent 
upon  the  prominence  of  the  large  canines,  which  stand  out  very 
markedly  at  the  angles  of  the  square.  The  incisors  present  a  flat  front 
and  project  slightly,  with  little  or  no  curve  of  the  incisive  line. 
The  bicuspids  and  molars  fall  backw\ard  from  the  canines  with  no  per- 
ceptible curve.  The  two  sides  are  quite  parallel,  but  sometimes  there 
may  be  a  slight  divergence  toward  the  cheek  at  the  rear.  This  is  the 
low  form  of  arch  which  appears  in  the  apes  and  some  low  races. 


THE  OCCLUSION  OF  THE  TEETH. 


19 


Second :  The  rounded  square  (Fig.  2,  h).  Tliis  is  the  medium 
arch  and  is  the  form  usually  met  with  in  ordinary,  well-developed  ro- 
bust Americans.  The  canines  seem  to  be  only  so  prominent  as  to  give 
character  to  the  arch  without  a  resemblance  to  the  arches  of  the  lower 
animals.  The  incisors  are  vertical  and  the  line  curves  slightly  from 
one  canine  to  the  other.  The  bicus})id-and-molar  line  curves  slightly 
outward  from  the  canine  and  converges  at  the  rear. 

Third  :  The  ROUNDED  ARCH  (Fig.  2,  c).  This  is  the  circular  or 
**  horse-shoe "  arch.  It  is  nearly  semicircular,  the  ends  curving  in- 
ward at  the  rear,  the  outlines  of  the  arch  tracing  a  decided  horse-shoe 
shape.  The  canines  are  reduced  to  the  level  of  the  arch,  so  that  there 
is  no  prominence  of  these  teeth.  The  bicuspids  and  molars  follow  the 
line  of  the  curve.  This  arch  is  quite  characteristic  in  some  races,  as 
the  brachycephalic  South  Germans. 

Fourth  :  The  rounded  V  (Fig.  2,  d).  In  this  form  the  round  arch  is 
constricted  in  front  or  narrowed  so  that  the  incisors  mark  a  small  curve 
whose  apex  is  the  centre.  It  is  the  arch  of  beauty  and  is  that  most 
admired  in  women  of  the  Latin  races. 

These  are  but  the  basal  forms  of  the  dental  arch.  Ordinarily,  mod- 
ifications of  these  types  occur  in  all  degrees ;  it  is  the  variations,  the 
composites,  which  are  most  met  with. 

5.  The  Occkision  of  the  Teeth. — The  upper  teeth  describe  the  seg- 
ment of  a  circle  larger  than  that  of  the  lower  teeth  ;  so  that  the  edges 
of  the  anterior  teeth  above  close  over  those  below,  and  the  buccal  cusps 
of  the  grinding  teeth  above  close  outside  of  the  buccal  cusps  of  the 
lower  teeth  (Fig.  3).  By  this  arrangement  the  buccal  cusps  of  the 
lower  grinders  are  received  into  the  de- 
pressions or  sulci  between  the  buccal  and 
lingual  rows  of  the  cusps  and  tubercles 
of  the  superior  molars  and  bicuspids,  and 
the  lingual  cusps  of  the  upper  grinders 
are  received  into  the  sulci  of  the  lower 
grinders.  By  this  arrangement  the  whole 
of  the  morsal  surfaces  of  these  teeth  are 
brought  into  contact  in  the  several  move- 
ments of  mastication,  thereby  rendering 
the  performance  of  this  function  more 
effective. 

Then,  again,  the  upper  incisors  usually 
close  over  the  lower  for  one-third  of  their 
length.     This  allows  of  the  shearing  action  by  which  the  incisive  func- 
tion is  performed  as  the  edges  of  these  teeth  are  drawn  past  each  other. 

The  line  of  the  horizon  of  occlusion  (Fig.  4,  ^1-^)  presents  a  decided 


Incisors. 


Fig.  3. 

Bicuspids. 


Molar.' 


The  relative   position  of  tlie  upper 
and  lower  teeth  in  occlusion. 


20 


MACROSCOPIC  A  SATO  MY   OF   THE  Ili'MAX   TEKTII. 


curve  from  front  to  rear,  oi'  tj^rcatcr  or  less  (leo;ro(>  in  dilfercnt  forms  of 
the  arch.  Tims  it  is  liioli  at  the  incisors,  cnrvinu'  downward  at  the  bicns- 
pids,  roachino-  its  lowest  [)oint  at  the  first  molar;  it  curves  upward  rap- 
idly at  the  second  molar,  and  is  highest,  again,  at  the  third.  In  the 
rounded  arch   the   plane  is   more  flattened,  and  it  exhibits  the  extreme 

Fig.  4. 


The  horizon  of  the  line  of  occlusion  and  plane  of  occlusion. 

dowuAvard  curve  in  the  square  arch.  Between  these  extremes  there 
is  of  course  every  variety  of  modification.  Tlie  form  of  the  plane  of 
occlusion  is  shown  in  Fig.  4,  C. 

Fjg.  5. 


The  apposition  of  the  upper  and  lower  teeth. 


The  tendency  of  the  bolus  of  food  is  toward  the  low^est  part  of  the 
curve  at  the  region  of  the  lower  first  molar,  so  that  the  extraction  of 
this  tooth  alw^ays  affects  the  performance  of  mastication. 

In  the  apposition  of  the  teeth  of  the  opposite  jaw's  the  mechanical 


THE  OCCLUSION  OF  THE  TEETH. 


21 


arrangement  is  such  tliat  the  dynamics  of  mastication  is  subserved 
and  the  greatest  effectiveness  secured  (Fig.  5).  Thus  the  morsal  sur- 
face of  the  upper  central  incisor  is  opposed  to  all  of  that  of  the  cen- 
tral incisor  below  and  to  the  mesial  half  of  the  lateral ;  the  upper  lat- 
eral opposes  the  distal  half  of  the  lateral  below  and  the  mesial  face  of 
tlie  canine  ;  the  upper  canine,  the  distal  half  of  the  face  of  the  lower 
canine  and  the  mesial  half  of  the  first  bicuspid;  the  upper  first  bicuspid 
opposes  the  distal  half  of  the  lower  first  bicuspid  and  the  mesial  half 
of  the  second  ;  the  upper  second  bicuspid  opposes  the  distal  half  of 
the  lower  second  bicuspid  and  part  of  the  lower  first  molar  :  the.  upper 
first  molar  opposes  the  distal  part  of  the  lower  first  molar  and  the  me- 
sial half  of  the  second  ;  tlie  upper  second  molar  opposes  the  distal  half 
of  the  lower  second  and  part  of  the  third  ;  and  the  upper  third  covers 
the  remainder  of  the  lower  third  molar. 

By  this  method  of  apposition  the  teeth  are  so  arranged  that  two 
teeth  receive  the  impact  of  half  of  two  of  the  opposite  jaw,  thus 
distributing  the  force  of  occlusion  and  ensuring  the  safety  and  strength 
of  the  teeth.  This  "  break-joint "  arrangement  permits  each  tooth  to 
bear  two   opposing  ones,  and   also   helps  to   preserve   the  alignment. 

Fig.  G. 


Incisors.     Canines  or   Premolars  or  Molars. 

cus2)id.i.        Bicuspids. 

The  classes  of  the  teeth,  comprising  the  left  half  of  a  full  denture. 


Then  again,  if  one  tooth  be  lost,  the  opposing  teeth  still  rest  against 
two  teeth,  one  at  each  side  of  the  space.  The  normal  condition  of 
the  articulation  is  rarely  preserved,  however,  as  mutilation  usually  dis- 
turbs it ;  the  teeth  move  on  account  of  the  force  of  occlusion,  and  effec- 
tive mastication  is  more  or  less  destroved. 


22  MACROSCOPIC  ANATOMY   OF   THE  HUMAN  TEETH. 

6.  Number  and  Classes  of  the  Teeth. — Man  has  tliirty-tAvo  teeth, 
divided  into  four  clai^ses,  viz. — (1st)  I^X'LSOR.s,  (2d)  canines  or  cuspids, 
(3d)  PiiE^roLARS  or  bicuspids,  and  (4th)  molars  (Fig.  6).  Tliis  is 
expressed  by  the  dental  formula  as  follows  : 


2—2         1—  1    ,.   2-2         3  —  3 

,    c.  ,01.     —    ,  m. 

2—2'        1  —  1'        2—2'        3  —  3 


(1)  The  incisors  are  eight  in  number,  four  above  and  four  below, — 
two  on  each  side  of  the  median  line.  The  two  next  to  the  median  line 
are  called  the  central  inckors,  the  ones  next  to  them  distally,  the  lat- 
eral incisors. 

(2)  The  canines  arc  four  in  number,  two  above  and  two  below, — 
one  on  each  side  immediately  approximating  the  lateral  incisor  on  the 
distal  side. 

(3)  The  bicuspids  are  eight  in  number,  four  above  and  four  below, 
— two  on  each  side  approximating  the  canines  on  the  distal  side. 
The  first  of  these  next  the  canine  is  called  the  first  blcusjyid,  the  one 
next  to  it  on  the  distal  side  the  second  bicuspid.  The  same  designa- 
tion applies  to  both  upper  and  lower  bicuspids. 

(4)  The  molars  are  twelve  in  number,  three  on  each  side  of  each 
jaw,  approximating  the  second  bicuspid  on  the  distal  side.  The 
molar  next  to  the  second  bicuspid,  both  above  and  below,  is  called  the 
first  molar ;  the  next  one  distally  is  called  the  second  molar  ;  the  next 
one  distally,  and  the  last  tooth  in  the  jaw,  is  called  the  third  molar  or 
"  wisdom  tooth  "  {dens  sapiential). 

Functionally,  the  incisors  are  formed  for  cutting,  as  their  name  im- 
plies ;  the  canines  for  prehension  and  tearing  (for  which  purpose  this 
tooth  in  lower  animal  forms  is  often  excessively  developed).  It  also 
serves  in  guiding  the  bite.  The  bicuspids  are  the  crushing  teeth,  and 
the  molars  are  formed  for  grinding,  triturating  and  insalivating  the 
food. 

The  Incisors. 

7.  The  Upper  Central  Incisor. — This  is  the  first  tooth  in  the  den- 
tal series  in  man.  It  is  situated  in  the  front  of  the  mouth,  next  to  the 
centre  of  the  arch,  which  is  the  mesial  border  of  the  intermaxillary 
bone.  In  adult  man  these  bones  fuse  with  the  anterior  borders  of  the 
right  and  left  superior  maxillary  bones.  Their  junction  with  each  other 
marks  the  centre  of  the  dental  arch. 

The  general  form  is  that  of  a  truncated  cone  with  its  top  flattened 
out  to  form  the  cutting  edge. 

Its  function  is  to  cut  or  incise  food,  hence  its  name  from  the  Lat. 
incisus,  "  to  cut  into." 


THE  INCISORS. 


23 


The  mechanical  stnicture  of  the  crown  is  a  matter  of  importance.  It 
will  be  observed  that  it  consists  of  several  elements  :  first,  a  broad  cut- 
ting blade  (Fig.  7,  a)  supported  by  two  strong  lateral  columns  (6)  on 

each   side,   and    that  these   columns 
are  upheld  by  two  strong  marginal 

Fig.  8. 


Fig. 


The  mechanical  design  of  the  crown  of 
the  upper  central  incisor :  a,  the  blade  ;  6, 
the  two  columns  supporting  the  blade ;  c, 
the  marginal  ridges  acting  as  guys,  brac- 
ing the  columns ;  d,  the  basal  ridge  as  the 
base  of  attachment  for  the  guys. 


d  f 

Diagram  of  the  labial  face  of  the  upper  central 
incisor. 


ridges  (e)  leading  up  from  the  loAvcr  ridge  (d).  These  ridges  are  but- 
tresses, which  gu}'  and  uphold  the  columns  which  contain  and  carry  the 
blade.  Hence,  when  these  ridges  are  destroyed  by  caries  or  in  operating, 
the  support  of  the  column  is  lost  and  the  blade  readily  breaks  away. 

The  form  of  the  crown  is  spade-like,  or  a  compressed-wedge  shape, 
the  edge  being  quite  thin  and  the  thickness  increasing  rapidly  to  the 
base.  It  is  slightly  bent  toAvard  the  lingual  side,  or  much  curled  over  in 
some  cases. 

The  labial  face  is  imperfectly  square  or  oblong,  the  cervical  margin 
being  rounded  (Fig.  8,  a).  It  is  convex  from  side  to  side,  but  only 
slightly  so  from  cervix  to  edge.  Two  shallow  depressions  or  furrows 
extend  the  length  of  the  face  perpendicularly  (6)  dividing  it  into 
thirds,  called  lobes, — the  mesial,  (e),  median  (d) 
aud  distal  lobes  (e).  These  furrows  and  lobes  are 
quite  conspicuous  when  the  tooth  is  erupted,  but 
are  abraded  by  age  and  the  wear  of  use  and  denti- 
frices, until  the  face  becomes  smooth.  The  mesial 
margin  is  a  little  longer  than  the  distal  so  that 
the  cutting  edge  slopes  upw^ard  toward  the  distal 
side  (/). 

The  lingiud face  is  smaller  than  the  labial, 
being  on  the  inner  and  smaller  curve  of  the 
crown,  and  is  narrower  from  side  to  side  (Fig.  9). 
It  is  triangular  in  outline,  being  wide  at  the  r-dge  and  narrow  and 
rounded  at  the  base  or  cervix.  The  marginal  ridges  {a)  are  high 
and  conspicuous,  and  extend  from  the  basal  ridge  to  the  edge  on  the 


Diasram  of  the  lingual  face 
of  the  upper  central  in- 
cisor. 


24 


MACROSCOPIC  ANATOMY  OF  THE  IIUMAy   TEETH. 


mesial  and  distal  inai;<>'iMs  of  (his  surface.  The  basal  ridii'c  {f>)  is  a 
strong-  elevation  continuous  with  the  marginal  ridges  at  the  hase  of 
the  crown.  It  is  sometimes  developed  into  a  raised  cusp,  the  ridge 
at  the  base  of  which  forms  a  cingulum.  A  ridge  or  lobe  (r)  extends 
from  the  basal  ridge  to  the  centre  of  the  edge,  uniting  with  the  median 
lobe  from  the  labial  face  to  form  the  median  tubercle.  A  dei)ression 
or  fossa  (cif)  is  found  on  each  side  of  the  median  lobe  between  it  and  the 
marginal  ridges,  or,  when  the  lobe  is  low  or  entirely  absent,  these  fossre 
mav  be  continuous.  A  fault  or  fissure  at  its  junction  with  the  basal 
ridae  forms  the  seat  of  caries  in  teeth  of  low  structure. 

The  mesial  face  (Fig.  10)  is  a  rather  long  triangle  in  shape,  with  a 
concaved  base  at  the  cervix  of  the  tooth  (a), 
and  a  long  point  toward  the  edge.  It  is 
nearly  straight  in  a  longitudinal  direction, 
but  rounded  and  convex  transversely.  It  is 
longer  than  the  distal  face,  the  edge  descend- 
ing in  that  direction.  The  enamel  line  dips 
downward  into  this  face,  and  there  is  a  de- 
Mesial.       Distal.         'J  pressiou  above  it  (h)  which  sometimes  extends 

The  mesial  and  distal  fiices  and     u])ward  ou  the  root.     The  point  of  contact 

edge  of  the  upper  central  in-  .  •  .       -i      •  ^.^  ^.^.• 

cigoj..  With  the  opposing  tooth  is  near  the  cutting 

edge. 

The  distal  face  is  also  triangular  in  outline  (Fig.  10)  but  it  is  more 
curved  in  the  longitudinal  axis,  so  that  this  surface  is  convex  in  all 
directions.  It  is  most  curved  in  the  transverse  direction.  The  enamel 
dii)s  downward  into  the  surflice  (d),  as  in  the  mesial,  but  there  is  not  so 
much  of  a  depression  above  this  line.  The  point  of  contact  is  one-third 
of  the  distance  from  the  angle  (e). 

The  edge,  or  morsal  margin,  of  the  crown  is  formed  liy  the  com- 
pression of  the  top  of  the  truncated  primitive  cone.  It  is  quite  wide 
and  square  except  at  the  distal  corner,  which  is  rounded.  The  angle 
w^itli  the  mesial  face  is  acute  (Fig.  10,  /).  When  the  tooth  is  first 
erupted,  the  edge  has  three  ]:)rominent  tubercles  (g),  which  correspond 
to  the  ridges  on  the  labial  and  lingual  faces.  These  are  soon  worn  off 
with  use,  so  that  the  edge  usually  looks  straight.  The  pitch  of  the 
edo-e  is  toward  the  median  line. 

The  neck  of  the  central  incisor  is  a  rounded  pear-shape  in  outline, 
the  labial  half  being  wider  (Fig.  11,  a)  than  the  lingual.  There  is  not 
much  constriction  of  the  tooth  at  the  neck.  The  enamel  edge  curves 
upward  on  the  root  on  the  labial  and  lingual  sides,  and  dijis  down- 
ward on  the  mesial  and  distal  flices.  It  terminates  abruptly  on  all 
sides,  especially  on  the  lingual,  where  a  considerable  ridge  is  some- 
times raised  (Fig.  10,  c). 


THE  I^'CISOBS. 


25 


Fig.  11. 


The  root  of  the  upper  cen- 
tral incisor. 


The  root  is  cone-shaped  and   tapering   (Fig.  11,  b).     The  ronnded 
pear-shaped  section  continnes  ahnost  to  the  end. 

The  pidj)  chamber  is  spacions  and  open,  and  of 
the  general  form  of  the  tooth  (a  and  c).  The  radi- 
cal portion  of  the  canal  gives  free  access,  but  the 
flattened  coronal  portion  is  difficult  to  cleanse.  In 
young  teeth  the  cornua  or  horns  of  the  pulp  may 
project  far  toward  tlie  angles  (c). 

8.  The  Lateral  Incisor. — This  tooth  approxi- 
mates the  central  incisor  on  its  distal  side,  and  is 
also  implanted  in  the  intermaxillary  bone.  It  is 
of  similar  si)ade-like  form  and  of  the  same  architectural  design  as  the 
central,  modified  by  the  distal  half  being  more  rounded  in  every  direc- 
tion. As  the  crown  is  narrower  than  the  central,  the  destruction  of  the 
marginal  ridges  on  the  lingual  face  weakens  the  edge  still  more,  so 
that  it  breaks  off  more  easily.  The  crown  is  narrower  in  the  mesio- 
distal  diameter  than  the  central,  but,  still  almost  as  wide  labio-lingually, 
the  relative  difference  of  thickness  in  the  two  directions  is  more  ap- 
parent. The  tooth  has  the  appearance  of  being  compressed  mesio- 
distallv.  The  thickness  increases  ra})idly  from  the  edge  to  the  neck 
(Fig.  12,  B). 

Fig.  12. 


^      ^  B  C  D 

The  upper  lateral  incisor. 


The  labial  face  (Fig.  12,  C)  is  more  rounded  than  that  of  the  cen- 
tral. It  is  half  incisor  and  half  canine  («),  the  mesial  half  toward  the 
central  incisor  resembling  that  tooth  (6),  and  tlie  distal  half  toward 
the  canine  resembling  it  (c).  The  mesial  angle  of  the  edge  is  quite 
acute,  while  the  distal  angle  is  rounded  and  obtuse.  The  three  lobes 
may  be  well  developed,  similar  to  those  on  the  central  incisor,  but 
are  usually  indistinct,  although  the  central  ridge  is  prominent. 

The  Ungual  f<Lce  (Fig.  12,  D)  is  much  depres.sed,  but  less  concave 
than  that  of  the  central  incisor.  The  marginal  (cZ)  and  basal  ridges  (e) 
are  quite  j^rominent.  The  basal  ridge  is  often  raised  into  a  prominent 
cingule  or  talon,  an  exaggerated  example  of  which  is  shown  in  Fig. 
13,  which  is  a  revival  of  the  basal  talon  found  in  the  apes, — and 
the    insectivora.     This  cingule  occurs  more  frequently  on   the   lateral 


Flo.  13. 


2B  MACROSCOPIC  ANATOMY  OF  THE  HUMAN   TEETH. 

incisor  tlinii  on  any  other  of  the  anterior  teeth.  The  depression 
above  it  is  often  the  location  of  a  fanlt,  a  fissnre  or  j)it,  whicli  be- 
comes the  seat  of  caries.  The  basal  rid^e  is 
sometimes  cnt  by  a  fissnre  which  leads  down  (jnite 
npon  the  neck  of  the  tooth  (Fig.  12,/). 

Sometimes  the  entire  surface  is  full  and  ronuded 
without  any  concavity  whatever. 

The  memd  face  (g)  is  of  triangular  form  similar 
05      to  that  of  the  central  incisor.    It  is  rounded  toward 
the  edge  labio-lingually,  but  flattened  at  the  neck, 
'^  with  a  depression  at  the  enamel  line  which  leads 

Showing   unusual    develop-  i    i  •    i 

ment  of  the  cinguie  or  Upward  upou  the  root.     The  labial  angle  is  some- 

basal  talon  on  an  incisor.    ^-^^^^^  ^j^^  ^^^^  ^^  ^  depression  (h),  which  o'ives  the 

(From  case  reported  by  Dr.  a  v    /? 

w.  H.  Mitchell,  Dental  Cos-  angle  a  hook  shapc.  The  depression  varies  in 
7?io.s  ^  0  .  xxxi\ .  p.  o  .)  width  and  depth  and  may  become  the  seat  of 
caries.  The  point  of  contact  with  the  central  incisor  is  at  the  junction 
of  the  lower  with  the  middle  third  of  the  length  of  the  face. 

The  distal  face  is  more  convex  in  all  directions  and  resembles  the 
canine  in  form,  being  in  harmony  with  the  general  form  of  the  distal 
half  of  that  tooth.  From  cervix  to  edge  it  is  rounded  and  the  contact 
eminence  in  the  middle  third  is  very  fidl  [i).  From  this  point  it  rounds 
off  rapidly  to  the  edge.  The  upper  third  is  depressed  rapidly  toward 
the  cervix,  wdth  a  considerable  depression  at  the  enamel  line  leading 
off  to  the  distal  groove  on  the  root. 

The  cdf/e  is  divided  into  two  portions  by  the  prominent  tubercle  (J) 
in  the  middle  which  terminates  the  prominent  central  ridge  of  the 
labial  face.  The  mesial  half  is  straight,  like  that  of  the  central. 
When  worn,  these  features  disappear  and  the  edge  becomes  almost 
straight.  The  pitch  of  the  edge,  like  that  of  the  central,  is  toward 
the  median  line. 

The  nech  is  much  flattened  mesio-distally,  and  is  of  a  compressed 
pear  shape,  or  flattened  oval  on  section.  The  enamel  margin  pursues 
the  same  course  as  on  the  central  incisor,  rounding  upward  toward  the 
root  on  the  labial  and  lingual  sides  and  dipping  downward  on  the 
distal  and  mesial.  It  does  not  terminate  so  abruptly  as  that  of  the 
central  incisor,  and  presents  less  of  a  ridge  at  the  gingival  margin. 

The  root  is  common Iv  lono-er  than  that  of  the  central  incisor,  is 
narrower,  flattened  mesio-distally  (Fig.  12,  A,  B).  It  tapers  gradually, 
not  rapidly  like  the  root  of  the  central  incisor.  It  is  a  flattened  oval 
on  section  (e).  Sometimes  there  is  a  hook  at  the  end,  curved  distally. 
Grooves  sometimes  occur  on  the  mesial  and  distal  sides. 

The  j^^dp  caned  is  flattened  in  conformity  to  the  shape  of  the  root, 
but  is  readily  entered  if  the  root  be  straight. 


THE  INCISORS. 


27 


The  lateral  incisor  is  very  irregular  as  to  form,  presenting  various 
degrees  of  deformity  or  abnormality,  and  may  sometimes  be  reduced  to 
a  mere  peg.  It  is  also  erratic  as  to  eruption,  being  sometimes  sup- 
pressed, not  appearing  for  several  generations  of  a  family.  It  follows 
the  third  molar  in  the  frequency  of  its  irregularities  both  as  to  form 
and  frequency  of  non-eruption. 

The  third  incisor  of  the  primitive  typal  mammal  sometimes  reap- 
pears in  man,  and  is  kno^vn  as  a  supernumerary.  It  rarely  assumes  the 
proper  incisor  form  and  position  in  the  arch,  but  usually  erupts  within 
the  arch  and  is  a  mere  pointed-peg-shaped  tootli. 

9.  The  Lower  Incisors. — These  are  most  conveniently  described  as 
a  group,  as  they  are  very  similar  in  form,  having  but  slight  variations 
between  the  central  and  lateral  incisors  to  be  noted. 

They  are  located  in  the  anterior  portion  of  the  lower  jaw,  upon  each 
side  of  the  median  line,  opposite  the  incisors  above.  Their  function  is  the 
same  as  that  of  the  upper  incisors,  the  cutting  of  food,  which  they  per- 
form by  opposing  the  upper.  The  lower  central  opposes  only  the  cen- 
tral above  ;  the  lateral,  both  the  upper  central  and  lateral  incisors. 

The  lower  central  incisor  is  the  smallest  tooth  in  the  dental  series. 
It  is  of  spade-like  form  (Fig.  14),  the  crown  being  a  double  wedge 
shape  («,  b).  The  first  wedge  {a)  is  observed  on  viewing  the  crown 
from  the  front,  the  widest  portion  being 
at  the  morsal  edge  and  the  point  at  the 
cervix.  The  second  wedge  is  observed 
from  the  side  {h),  the  widest  part  being 
at  the  neck  and  the  point  at  the  morsal 
edge  of  the  crown.  The  edge  is  thin, 
but  the  labio-lingual  diameter  increases 
rapidly  to  the  cervix,  which  is  the 
widest  pnrt.  The  crown  is  widest 
mesio-distally  at  the  edge,  but  diminishes  to  the  neck,  which  is  scarcely 
more  than  half  the  width  of  the  edge.  The  tooth  cone  is  therefore 
compressed  in  one  direction  at  the  edge,  and  in  another  at  the  cervix. 
The  mechanical  elements  are  the  same  as  those  of  the  upper  central,  but 
with  tlie  parts  less  strongly  marked. 

The  labial  face  is  a  long  wedge  shape  {a),  the  widest  part  at  the 
edge  and  narrowing  to  the  cervix.  It  is  usually  straight,  or  nearly 
so,  longitudinally,  and  straight  across  the  edge,  but  round  and  con- 
vex at  the  neck  and  the  cervical  half.  Sometimes  vertical  ridges  are 
found  on  these  teeth  wlien  they  are  first  erupted,  but  these  soon 
wear  oif. 

The  UmjuaJ  face  is  depressed  and  concave  from  edge  to  cervix  (c), 
but   less  so  fnmi  side   to   side.       The  maroinal   ridges  are  often   well 


The  lower  incisor. 


28  MAcnosroi'/c  axatomy  of  the  human  teeth. 

marked.  In  tlic  latci'al  iiicisoi-  the  lossa  is  often  more  marked  and 
the   marginal   )'ido-es  more  distinct. 

The  //;r.s/<^/and  (fixfal  sides  are  of  wedge-like  form,  straight  from  edge 
to  cervix  and  widening  in  the  same  direction.  A  depression  runs  across 
the  neck  just  above  the  enamel  line. 

The  neck  is  much  compressed  disto-mesially,  and  the  root  ])artakes 
of  this  flattening  through  its  entire  length.  The  section  presents  a 
compressed  oval  {e).  The  enamel  line  dips  downward  on  the  labial  and 
lingual  sides,  and  curves  upward  on  the  UK^sial  and  distal,  in  a  manner 
characteristic  of  the  incisors. 

The  edge  is  perfectly  straight  from  side  to  side,  after  the  three  tuber- 
cles, found  when  first  erupted,  are  worn  olf. 

The  root  is  flattened  like  the  neck,  and  frequently  a  groove  runs  the 
entire  length  on  the  mesial  and  distal  sides.  Occasionally  complete 
bifurcation  results,  which  recalls  the  form  of  this  tooth  found  in  lower 
animals. 

The  pulp  canal  (e)  is  of  similar  form  to  the  root,  and  is  flattened 
and  thin,  so  that  it  is  often  difficult  to  effect  an .  entrance  to  it  with 
instruments. 

The  lateral  is  similar  in  form  to  the  central  incisor,  but  is  wider  at 
the  edge  and  the  distal  corner  of  the  edge  is  slightly  rounded  (d).  In  all 
other  features  it  resembles  the  central  incisor. 

The  Canines  or  Cuspids. 

10.  The  Upper  Canine. — This  is  the  third  tooth  from  the  median 
line  and  a])proxiniates  the  lateral  incisor  on  its  distal  side.  It  is  the 
first  tooth  ])osterior  to  the  intermaxillary  suture  and  is  imbedded  in 
the  maxilla  proper.  It  is  commonly  said  to  form  the  spring  of  the 
arch,  and  conveys  the  impression  of  great  strength,  as  is  indicated  by 
its  strong  implantation.  It  is  more  strongly  implanted,  and  by  a  longer 
and  larger  root,  than  any  of  the  other  teeth.  Zoologically  it  is  the 
largest  tooth  in  the  dental  series,  but  in  man  is  much  reduced  from 
its  prototype,  the  larger  carnassial  canine  of  lower  animals,  especially 
the  carnivora.  It  is  the  principal  prehensile  tooth,  and  is  therefore 
first  in  order  of  function  in  the  dental  series. 

The  canine  in  man  preserves  the  typal  form,  for  its  mechanical 
structure  is  still  that  of  a  single  cone,  brought  to  a  point  (Fig. 
15,  a).  This  is  the  earliest  form  of  teeth  found  in  the  lower  verte- 
brates, the  fishes  and  reptiles,  which  present  only  simple  conical  teeth 
in  all  parts  of  the  jaw.  It  has  an  older  history  than  any  other  tooth, 
and  still  bears  the  marks  of  the  many  changes  through  whicli  it  has 
passed  in  the  course  of  its  evolution. 


THE  CANINES  OR   CUSPIDS. 


29 


The  croion  has  a  spear-head  shape  (6),  hence  the  name,  cuspid,  by 
which  this  tooth  is  frequently  designated,  from  the  Lat.  cuspis,  ''  point, 
pointed  end,"  It  is  constructed  essentially  for  piercing  and  tearing. 
The  central  cusp  or  point  is  braced  in  all  directions  ;  the  edges  leading 
up  to  it  both  mesially  and  distal ly  (which  serve  for  cutting  as  well),  the 

Fig.  15. 


The  upper  canine. 


strong  labial  ridge  coming  downward  from  the  cervix  (c)  to  the  median 
ridge  leading  up  on  the  lingual  surface  (r/),  all  support  it  in  the  office 
of  prehension  and  the  laceration  of  flesh. 

The  labial  face  (b)  presents  the  outlines  of  the  spear  shape,  more  or 
less  rounded  in  different  cases.  Starting  from  the  well-defined  cusp  just 
in  front  of  the  central  axis  of  the  tooth,  it  widens  sharply  for  about 
one-third  of  its  length,  whence  it  narrows  gradually  to  the  gum  line, 
which  is  fullv  rounded.  In  some  cases  the  mesial  and  distal  anules  are 
rounded  and  the  outlines  are  more  of  a  leaf  shape  {e).  The  surface 
is  slightly  rounded  mesio-distally,  so  that  the  sides  slope  roundlv  or 
flatly  away  from  the  central  ridge.  This  ridge  descends  from  the  middle 
of  the  cervical  margin,  curving  slightly  forward  and  then  backward  to 
the  point  of  the  cusp  (c).  This  curve  recalls  the  curving  shape  of  this 
tooth  in  the  Felidse.  It  is  usually  a  sharp,  prominent  ridge,  but  may 
be  reduced  and  rounded  so  as  to  be  scarcely  perceptible.  The  three  lobes 
of  the  surface  are  imperfectly  marked, — the  central  ridge  dominating 
and  dwarfing  the  lateral  ones.  The  lateral  furrows  on  each  side  of 
the  central  ridge  separating  it  from  the  lateral  lobes  are  more  or  less 
marked,  especially  toward  the  edge.  Wear  reduces  in  time  the  prom- 
inence of  the  lobes  and  ridges  and  obliterates  the  furrows. 

The  Un(juaJ  face  is  of  similar  spear  shape  (r/),  but  is  more  flat.  It  is 
rarely  concave.  The  thickness  of  the  crown  increases  gradually  to 
the  lateral  prominences,  which  gives  a  blade-like  edge,  then  rapidly 
to  the  shoulder  at  the  base.  A  strong  vertical  ridge  extends  from  the 
cusp  to  the  basal  ridge  {d),  with  a  slight  concave  depression  on  each 
side.  The  basal  ridge  is  well  marked  and  sometimes  develops  into 
a  cingule,  more  or  less  marked.     The  marginal  ridges  lead  up  on  each 


30  MACROSCOPIC  ANATOMY  OF  THE  HUMAN  TEETH. 

side  only  so  far  as  tlie  lateral  protuberances.  They  are  not  strongly 
marked  as  u  rule.  The  fossie  on  eaeh  side  of  the  vertieal  median  ridge, 
between  it  and  the  marginal  ridges,  may  be  quite  deep  but  are  usually 
shallow  and  ill  defined. 

The  mesial  face  in  outline  is  not  unlike  the  central  incisor,  l)ut  its 
contour  is  very  different,  for  it  is  more  or  less  rounded  in  all  direc- 
tions, and  the  lateral  eminence  in  the  lesser  third  makes  this  part  espe- 
cially full  (i).  From  this  point  the  surface  is  depressed  roundly  to  the 
enamel  line  at  the  neck,  where  a  depression  of  greater  or  less  depth  is 
found.  It  is  somewhat  flattened  at  the  cervix.  The  point  of  contact 
is  at  the  eminence,  which  touches  the  lateral  incisor. 

The  dldal  face  is  of  similar  form  to  the  mesial,  except  that  it  is  more 
full  and  the  eminence  more  pronounced,  which  gives  the  increased  width 
of  the  crown  on  that  side.  The  surface  descends  rapidly  tow^ard  the  neck 
and  is  rounded  labio-lingually.  The  point  of  contact  with  the  first  l^i- 
cuspid  is  on  the  lateral  protuberance. 

The  morsal  edge  presents  a  prominent  cusp  which  is  almost  central 
to  the  long  axis  of  the  tooth.  The  side  facets  slope  away,  but  still  retain 
their  cutting  edge  (6).  The  distal  side  of  the  edge  is  longer  than  the 
mesial,  by  reason  of  the  increased  size  of  the  distal  protuberant  angle. 
The  sharp  point  is  soon  worn  off  to  a  rounded  cusp,  and,  as  wear 
increases  with  age,  it  may  be  reduced  to  a  straight  surface  between  the 
mesial  and  distal  protuberances  (g). 

The  neck  is  a  flattened  oval  on  section,  or  the  lateral  direction  of  the 
labial  portion  may  be  greater  than  that  of  the  lingual  (h).  The  enamel 
line  preserves  the  same  curves  as  on  the  incisors,  /.  e.  rounding  upward 
on  the  labial  and  lingual  surfaces  and  dipping  downward  on  the  mesial 
and  distal.  The  enamel  terminates  gradually  with  but  a  slight  ridge, 
unless  it  should  be  on  the  lingual  side.  A  depression  occurs  on  both 
mesial  and  distal  sides  above  the  curve,  which  may  lead  up  as  a  groove 
on  the  root. 

The  root  is  longer  than  that  of  any  other  tooth,  and  it  is  at  least 
one-third  larger  than  that  of  the  central  incisor.  It  is  of  a  rounded 
trihedral  form,  or  irregularly  conical.  It  is  usually  straight,  and  tapers 
to  a  slender  point,  which  may  be  curved  or  very  crooked.  In  well- 
arranged  dentures,  where  it  has  erupted  naturally,  it  is  usually  straight. 

The  pw/p  canal  is  large  and  open,  of  the  same  form  as  the  tooth,  and 
easilv  entered.  It  is  regularly  formed  except  in  those  cases  Avhere  the 
root  is  curved,  and  even  in  these  it  can  be  filled  if  not  too  crooked,  as 
it  is  so  open  and  accessible. 

11.  The  Lower  Canine. — This  is  similar  to  the  upper  in  form  and 
outline,  except  that  it  is  somewhat  smaller,  more  slender,  and  more 
rounded  in  form  (Fig.  16,  a).     It  differs  also  in  being  more  compressed 


THE  CANINES   OB   CUSPIDS. 


31 


mesio-distally  and  in  beinfr  flattened  in  the  neck  and  root.  The  crown 
leans  backward  on  the  root  so  that  the  mesial  face  is  almost  straight  the 
entire  length  of  root  and  crown.  It  forms  the  spring  of  the  lower  arch, 
and  is  strongly  built  to  oppose  the  strong  upper  canine  in  the  act  of 
prehension  and  tearing.  It  opposes  the  mesial  surface  of  the  canine 
above  and  the  distal  surface  of  the  upper  lateral  incisor. 


The  lower  canine. 

The  labial  face  is  a  long  oval  (a),  the  cusp  being  blunt  and  the  neck 
rounded  while  the  mesial  side  (e)  is  flattened.  The  lobes  are  indistinct 
and  the  central  ridge  rounded  from  side  to  side.  The  entire  face  is  in- 
clined inward  to  accommodate  the  occlusion.  The  crown  in  many  cases 
presents  the  appearance  of  being  blunt  toward  the  distal  side. 

The  lingual  face  (6)  is  flat,  sometimes  cup-shaped,  and  the  marginal 
ridges  are  not  prominent.  The  central  ridge  sometimes  stands  out 
strongly.  The  basal  ridge  is  weak  and  is  rarely  developed  into  a 
cingule.  The  crown  increases  gradually  in  thickness  from  the  point 
to  the  neck. 

The  iiwrsal  surface  presents  a  mere  rounded  eminence  ;  the  cusp  may 
be  sharp  in  childhood,  but  usually  it  is  soon  reduced  by  wear.  Some- 
times it  remains  sharp  and  prominent.  The  lateral  edges  are  not  devel- 
oped, but  are  mere  ridges  leading  down  to  the  lateral  faces,  which  are 
not  prominent,  except  the  distal  {«1),  which  is  often  full. 

The  mesial  face  is  quite  flat,  and  straight  with  that  face  of  the  root. 
The  eminence  is  not  marked.  It  is  rounded  only  at  the  eminence,  but 
flattened  at  the  cervical  third  (c). 

The  distal  face  has  the  most  prominent  eminence  (r/),  the  crown  being 
bent  in  that  direction.  The  cervical  third  of  this  face  is  flat.  It  descends 
rapidly  from  the  eminence. 

The  neck  is  usually  oval  (/)  or,  when  compressed,  spindle-shaped 
upon  section  {g),  being  depressed  on  the  mesial  and  distal  sides  at  the 
origin  of  the  grooves  running  up  on  the  root.  The  enamel  line  is 
not  so  variable  as  on  the  incisor,  but  more  nearly  on  a  level  on  all  four 
aspects. 


32 


MACROSCOPIC  ANATOMV   OF   THh'   HUMAN   TKKTIi. 


Tli(>  roof  is  long:,  iiattencd,  and  tapering  [a,  b,  c).  It  is  shdrtcr  tlum 
that  ot'the  up])or  canine.  It  is  grooved  on  tlie  mesial  and  distal  sides, — 
so  niueh  so  as  to  tend  toward  bifurcation.  This,  indeed,  sometimes  hap- 
])ens  in  man,  thereby  recalling  the  ibrm  usual  to  the  primates  and  some 
other  lower  animals. 

T\w  jjtt/jj  c((ii(i/ \i^  of  the  same  general  I'onii  as  the  root,  often  ])re- 
senting  the  spindle  shape  on  section.  It  is  somew  hat  dilVieult  to  enter 
on  acconnt  of  its  flattened  sha})e  and  narrowed  channel. 


The  upper  bicuspids. 

nient  of  a  root  to  snpport  it. 


The  Bicuspids. 

12.  The  Upper  Bicuspids, — The  npper  bicuspid  is  formed  bv  duplica- 
tion of  the  primitive  cone  and  cusp  in  a  transverse  direction  (Fig.  17,  a). 

Viewed  from  the  standpoint  of  com- 
l)arative  dental  anatomy,  the  external 
cone  is  the  canine  cone — and  to  this  is 
added  the  internal  or  bicuspkl  cone,  the 
tooth  being  a  donble  canine.  The  bi- 
cuspids are  the  first  of  the  complex 
teeth.  The  internal  cusp  is  formed 
by  the  raising  of  the  inner  primitive 
cusp  of  the  canine  and  the  develop- 
The  distinctive  featiu'c  of  the  architec- 
ture, therefore,  is  its  formation  from  two  cones,  and  this  makes  it  a 
weak  tooth  as  regards  its  mechanical  structure  and  resistance  to  mas- 
tication, for  the  binding  of  the  bases  of  the  cones  and  cusps  depends 
upon  the  connecting  power  of  the  two  marginal  ridges  (6,  h),  and  when 
these  are  destroyed  the  cones  readily  part  and  split  off. 

The  bicuspids  in  man  are  homologous  with  the  premolars  of  the 
quadrumana  and  other  lower  mammals.  They  succeed  and  displace  the 
molars  or  grinders  of  the  deciduous  set.  They  are  placed  next  after  the 
canines  in  both  jaws,  and  midway  between  the  cutting  and  grinding  teeth. 
Their  function  is  the  crushing  of  food  preparatory  to  mastication. 

The  upper  first  bicuspid  approximates  the  canine  on  the  distal  side. 
The  buccal  face  (c)  is  of  spear-head  shape,  similar  to  that  of  the 
canine.  This  is  more  apparent  in  some  lower  mammals  than  in  man,  in 
whom  it  is  much  reduced  and  rounded,  so  as  to  give  usually  the  a])])ear- 
ance  of  a  long,  rounded  oval.  The  buccal  cusp  (c)  rises  sharply  and 
prominently  from  the  lower  centre  of  the  face,  from  which  a  strong  ridge 
{(T)  leads  up  to  the  cervical  border.  The  mesial  and  distal  lobes  {e,  e)  are 
rarely  conspicuous,  and  the  furrows  between  them  and  the  central  ridge 
lead  but  half  way  up  the  crown.  The  lobes  sometimes  have  prominent 
points   at   the  morsal  margins  which  in  lower  mammals  become  pro- 


THE  BICUSPIDS.  33 

noiinced  cingules.  The  buccal  maro;inal  rida^es  de?^cend  from  the 
points  of  the  cusp  to  the  points  of  the  lateral  lobes.  The  distal  ridge 
is  usually  longer  than  the  mesial.  The  cervical  border  is  rounded  and 
oval  from  side  to  side. 

The  lingual  face  (/)  is  full  and  rounded,  more  or  less  straight  perpen- 
dicularly and  rounded  mesio-distally.  It  is  convex  in  both  directions. 
The  lingual  cusp  rises  over  it  full,  but  is  blunt  and  round  ;  the  mar- 
ginal ridges  are  rounded,  not  angular,  and  curve  sharply  round  to  meet 
the  mesial  and  distal  marginal  ridges. 

The  mesial  face  (Fig.  18,  g)  is  wide  and  flat  transversely,  full  at 
the  morsal  surface  at  the  marginal  ridge,  which  is  prominent,  and  de- 
scending flat  to  the  cervix,  where 

a  depression  (h)  occurs  which  ex-  ^^^'-  ^'^- 

tends  well  up  the  face. 

The  distal  face  is  of  similar 
form,  but  is  rather  more  convex 
and  the  portion  at  the  marginal 
ridge  more  prominent.  The  de- 
pression from  the  root  does  not 
extend  so  far  up  on  the  face.  "^  „,  ,  •       -^ 

i  The  upper  bicuspids. 

The  morsal  sioface  shows  an 
abrupt  change  from  that  of  the  canine  next  to  it,  as  it  presents  two 
distinct  cusps  or  points  instead  of  one.  One  cusp  is  on  the  buccal 
margin  {j)  of  the  crown,  and  one  on  the  lingual  (k),  and  they  are  named 
the  buccal  and  lingual  cusps.  The  buccal  cusp  is  sharp  and  prominent, 
and  is  not  unlike  the  single  canine  cusp.  The  lingual  cusp  is  broader 
and  more  rounded — indeed  it  is  preferable  to  term  it  a  tubercle. 

The  outline  of  the  morsal  surface  is  imperfectly  quadrate  and  is  bor- 
dered by  Avell-marked  mari>:inal  ridy-es,  named  as  follows  : 

The  mesial  marginal  ridge  {I),  bordering  the  mesial  face  of  the  crown  ; 
the  distal  marginal  ridge  on  the  distal  side  {m),  the  buccal  marginal 
ridges  (n)  descending  from  the  point  of  the  buccal  cusp  to  meet  the  buc- 
cal terminations  of  the  distal  and  mesial  marginal  ridges  at  the  angle 
formed  by  the  junction  with  the  buccal  lateral  lobes  (o),  and  the  lingual 
marginal  ridges  (p),  descending  from  the  lingual  tubercle  to  meet  the 
lingual  termination  of  the  mesial  and  distal  marginal  ridges. 

The  triangular  ridges  descend  from  the  cusps  toward  the  centre  of 
the  tooth  and  unite  at  the  central  groove.  In  defective  teeth  they  do 
not  fuse,  leaving  a  fault  or  Assure  which  becomes  the  seat  of  caries. 
This  groove  or  sulcus  extends  from  one  lateral  marginal  ridge  to  the 
other  mesio-distally  (r)  and  Avidens  into  the  mesial  and  distal  sulci  at 
each  end.  The  triangular  grooves  (.s)  run  from  the  mesial  and  distal 
sulci  toward  the  mesial  and  distal  angles,  dividing  the  marginal  ridges 
3 


34  MACROSCOPIC  ANATOMY  OF  THE  HUMAN  TEETH. 

from  the  triangular.  They  also  become  the  seat  ot"  caries  in  imperfectly 
formed  teeth. 

The  neck  of  the  first  bicuspid  is  com])rcssed  or  s|)indlc-shitpcd  (/), 
the  enamel  line  rising-  on  the  buccal  and  linoiial  sides  and  di])j)ing 
down  on  the  mesial  and  distal.  TJie  enamel  margin  tapers  oft' gradually 
on  to  the  root.  A  wide,  deep  depression  usually  occurs  [a)  on  the  mesial 
side  of  the  neck,  leading  to  the  groove  on  the  root.  On  the  distal  face 
this  is  not  so  well  marked. 

The  root  is  much  flattened  mesio-distally,  with  a  decaded  groove  ex- 
tending up  both  sides.  This  grooving  tends  to  cause  bifurcation  of  the 
root,  which  actually  occurs  in  one-third  of  the  cases,  especially  in  persons 
of  strong  build.  This  bifurcation  is  a  persistent  relic  of  lower  forms 
of  the  premolars,  as  in  the  apes. 

The  root  canal  is  fiat  at  the  neck,  and  nearly  always  bifurcated,  even 
when  the  root  is  not  separated.  This  is  readily  seen  by  holding  a  bicus- 
})itl  having  one  root,  up  to  the  light,  when  the  central  portion  will  l)e  ob- 
served to  be  translucent.  The  usual  bifurcation  necessitates  the  search 
for  both  canals  in  every  case  in  treating  this  tooth. 

The  upper  second  bicuspid  (w)  approximates  the  first  on  the  distal 
side,  and  is  similar  to  it  in  every  way,  except  that  it  is  usually  smaller  and 
more  rounded  in  all  directions.  The  sharp  features,  conspicuous  ridges, 
etc.  are  not  so  strongly  marked.  The  cusps  are  reduced,  the  ridges  more 
rounded,  and  the  morsal  face  more  flattened,  and  it  is  often  wrinkled. 
The  triangular  ridges  are  more  likely  to  be  united,  thus  making  the  crown 
stronger.  The  crown  is  thinner  mesio-distally.  The  neck  is  more 
rounded  or  oval. 

A  most  conspicuous  difference  is  in  the  root,  which  is  narrower  labio- 
lingually,  is  more  rounded,  and  is  rarely  bifurcated.  It  is  sometimes 
cylindrical  or  cubical  in  form.  It  is  disposed  to  be  turned,  and  is  often 
crooke<^l.     The  ^yulp  canal  is  single  and  readily  entered. 

13.  The  Lower  Bicuspids. — These  are  placed  next  after  the  lower 
canines  on  the  distal  side.  In  form  they  are  not  truly  bicuspid,  for  the 
first  is  unicuspid  and  the  second  is  tricuspid  in  the  pure  typal  forms ; 
but  they  are  arbitrarily  termed  bicuspids  on  account  of  their  position  as 
compared  with  the  upper  bicuspids,  which  are  typically  bicuspid. 

The  architectural  form  of  these  teeth  is  that  of  the  single  cone,  the 
crown  being  augmented  in  various  directions  by  the  addition  of  cin- 
gules  to  the  primitive  cusp. 

The  lower  first  bicuspid  is  a  well-formed  transitional  tooth,  for  it 
grades  from  canine  to  bicuspid  and  is  typically  composite.  It  more 
closely  resembles  a  canine  than  a  bicuspid  in  its  usual  form,  because 
the  inner  cusp  is  almost  suppressed  and  is  rarely  as  large  as  the  outer 
one  (Fig.  19,  a).     In   fact,  it  looks  like  a  canine  with  a  cingule  raised 


THE  BICUSPIDS. 


35 


upon  its  inner  face.     This  cusp  is  really  a  cingule,  for  it  is  rarely  raised 
to  the  full  height  of  a  cusp. 

It  varies  much  in  size  from  a  mere  point  on  the  basal  ridge  (6)  on 
through  various  degrees  of  development,  up  to  a  full  cusp  as  large  as 
the  buccal  cusp,  when  the  tooth  becomes  a  true  bicuspid.  The  tooth  is 
therefore  essentially  a  primitive  unicuspid  premolar,  of  the  form  of  this 
tooth  in  some  of  the  lower  primates. 

'  The  buccal  face  (c)  is  caniniform,  or  a  long  oval  in  outline  with 
the  cusp  rising  as  an  abrupt  point  above  it.  The  angle  of  the  junc- 
tion of  the   marginal  ridges  may  stand    out  prominently.     The    face 


The  lower  first  bicuspid. 

curves  markedly  toward  the  lingual  side,  so  that  the  buccal  cusp  becomes 
central  to  the  long  axis  of  the  tooth  (a).  The  cervical  border  is  rounded 
at  its  margin  and  convex  from  side  to  side.     The  lobes  are  not  marked. 

The  Ungual  face  {d)  is  convex  from  side  to  side  and  straight  vertically, 
but  is  not  perpendicular,  as  it  is  directed  toward  the  lingual  side.  Its 
height  depends  upon  the  height  of  the  lingual  cingule,  which  varies  from 
a  mere  buccal  ridge  through  various  degrees  up  to  the  full-sized  cusp. 

The  mesial  and  distal  surfaces  are  of  similar  form,  convex  from  side 
to  side  {a,  h)  slightly  flattened  at  the  cervical  border  and  flaring  out  to 
meet  the  full  marginal  ridges,  which  are  round  and  prominent.  The 
prominence  of  these  ridges  and  the  inward  inclination  of  the  lingual 
face  gives  the  crown  a  decided  bell  shape,  tapering  to  the   neck  (r/). 

The  morsal  surface  (e)  is  peculiar  and  difl'ers  from  every  other  tooth 
in  its  great  variability  and  the  extremes  which  it  may  present,  from 
being  a  full  bicuspid  to  a  mere  canine.  This  face  is  nearly  circular  in 
outline,  the  widening  of  the  lateral  surfaces  by  the  spreading  of  the 
marginal  ridges  (/, /)  adding  to  the  width.  The  buccal  cusp  (g)  is  large 
and  prominent,  and  is  also  drawn  toward  the  centre  of  the  tooth  to 
accommodate  the  occlusion.  Sometimes  it  is  high  and  sharp  when  the 
lingual  cusp  is  reduced,  and  is  low  and  blunt  when  the  latter  is  en- 
larged,— appearing  to  have  an  inverse  ratio  in  size  to  the  inner  cusp. 
The  lingual  tubercle  or  cingule  varies  much  in  size,  from  a  mere  point 
on  the  liasal  ridge,  above  the  cervical  border,  to  a  pronounced  cingule, 
a  larger  cingule,  a  small   cusp,  then  a  full  cusp,  the  basal   ridge    (h) 


36  MACROSCOPIC  ANATOMY  OF  THE  HUMAN  TEETH. 

being  raised  with  it.  The  ridges  are  the  mesial  and  distal  marginal 
ridges  (/,  /),  which  are  bowed  out  round  and  full  and  are  always  j)ro- 
nouuced  ;  the  buccal  marginal  ridges  {/,/),  leading  down  from  the  buc- 
cal cusp  to  form  an  angle  with  the  mesial  and  distal  marginal  ridges ; 
the  basal  ridge,  when  the  lingual  cingule  is  lowered  (h) ;  and  the  tri- 
angular ridge  of  the  buccal  cusj),  which  is  always  large  and  when  the 
inner  tubercle  is  reduced  leads  down  as  a  high  central  eminence.  The 
lingual  cingide,  as  a  rule,  possesses  no  triangular  ridge. 

The  central  groove  usually  crosses  the  central  ridge  (A-),  but  not 
always,  being  often  bowed  around  its  lower  termination.  Sometimes  the 
ridge  is  crossed  by  a  sulcus.  The  groove  terminates  in  a  sulcus  at  each 
end,  with  slight  triangular  grooves  branching  up  on  the  buccal  (!usp. 
The  necJx  is  usually  oval  on  section,  being  much  constricted,  the  crown 
flaring  upward  from  the  cervical  portion,  giving  the  crown  the  well- 
known  bell  shape.  The  enamel  line  dips  but  slightly,  being  usually 
level  on  all  four  sides.  The  buccal  border  sometimes  presents  a  prom- 
inent ridge. 

The  root  is  single,  long,  tapering  and  may  be  nearly  round,  but  is 
usually  flattened  mesio-distally.  It  is  sometimes  thick  the  greater  part 
of  its  length,  and  terminates  in  an  abrupt,  round,  blunt  apex  (c,  (J).  It 
is  very  liable  to  be  crooked.  It  is  rarely  bifurcated  and  does  not  pre- 
sent grooves  on  its  lateral  faces. 

The  pulp  canal  is  constricted  and  flattened  at  the  neck,  and  the  back- 
ward inclination  of  the  teeth  makes  it  difficult  to  enter.  The  possibility 
of  the  root  being  crooked  and  the  peculiarity  of  its  anatomical  rela- 
tionships '  also  increase  the  uncertainty  of  treatment,  which  makes  the 
pulp  canals  of  the  lower  bicuspids  difficult  to  deal  with. 

The  lo"wer  second  bicuspid  aj)proximates  the  first  on  its  distal  side. 
It  resembles  the  first  as  regards  the  general  form  of 
^^*^'-  -^-  the  crown,  its  tapering  bell  shape,  the  constriction  of 

the  neck,  and  the  shape  of  the  root.  In  all  these 
features  there  is  little  difference  between  these  teeth, 
and  the  description  of  the  first  will  apply  also  to  the 
second  bicuspid. 

The  m.orsal  surface  (Fig.  20),  however,  differs  very 
I,  materially  from  that  of  the  first.     This  is  circular  in 

Themorsai  surface  of     outline  like  the  first,  and  the  l)uccal  cusp  is  full  and 

the  lower  second  bi-  i     i   /    \    i  i       •  •      t    •  i     i  i 

cuspid.  rounded  (a),  but  the  niner  cusp  is  divided  by  a  groove 

(6)  running  over  it,  into  two  parts,  so  that  it  is  really 

divided  into  two  tubercles.    This  makes  the  lower  second  bicuspid  in  its 

typal  form  a  tricuspid  tooth  ;  so  that  it  differs  from  the  lower  first,  which 

has  but  one  cusp,  and  from  the  others,  which  have  but  two  cusps.     The 

^  See  page  G06,  Chapter  XXI.,  on  Extraction  of  Teeth. 


THE  MO  LABS.  37 

lingual  tubercles  vary  much  in  size,  so  that  one  may  be  suppressed  and 
the  tooth  seem  bicuspid.  The  mesial  lingual  tubercle  (e)  may  be  of 
large  size  and  be  developed  at  the  expense  of  the  distal  (d)  ;  this  may 
be  a  mere  cingule  on  the  distal  marginal  ridge  and  appear  on  the  distal 
side,  but  it  is  always  present. 

The  morsal  groove  (e)  is  triangular  in  design,  passing  between  each 
of  the  three  tubercles.  A  well-marked  triangular  ridge  descends  from 
each  of  the  cusps. 

The  tricuspid  form  of  the  morsal  surface  of  this  tooth  is,  of  course, 
a  reproduction  of  the  trituberculate  premolars  of  the  lower  primates, 
and  of  still  lower  mammals,  although  the  triangular  form  of  the  crown 
is  lost  in  man. 

The  Molars. 

14,  The  Tuberculate  Teeth. — Molar  teeth  appear  early  in  the  scale 
of  vertebrate  life ;  mere  crushing  teeth  are  found  in  fishes  and  slightly 
tuberculate  teeth  in  the  reptiles.  The  grinders  are  of  simple  form  in  the 
lowest  vertebrates.  The  Bruta  have  simple,  flat-crowned  molars,  which 
are  undiiferentiated  and  used  merely  for  crushing.  Tuberculate  molars 
appeared  early  in  the  placental  mammalia,  the  trituberculate  molars  being 
found  in  numerous  fossil  species,  which  are  the  typal  form  and  forerunners 
of  the  tuberculate  molars  in  the  liigher  mammalia.  The  simjjle-crowned 
tooth  with  a  single  tubercle  {hap/odonf,  Cope),  becomes  duplicated  and 
doubled,  with  a  crown  supporting  several  tubercles  [hunodont).  The 
transition  from  simple  to  complex  teeth  is  accomplished  by  the  repeti- 
tion of  the  type  in  diiferent  directions  and  the  addition  of  cusps  and 
roots  both  laterally  and  longitudinally  of  the  jaw.  The  upper  molar  is 
formed  by  the  addition  of  the  third  cusp  to  the  bicuspid  type  and  has 
three  roots,  which  support  three  or  four  tubercles.  Lower  molars  con- 
sist of  four  cones  which  support  four  or  five  tubercles.  The  low^er  mo- 
lar is  therefore  the  more  complex  tooth.  The  bicuspid  is  more  complex 
than  the  canine,  the  upper  molar  than  the  bicuspid,  the  lower  than  the 
upper  molar. 

The  molar  teeth  of  man  are  bunodont  in  form,  /.  e.  thev  have  simple 
rounded  tubercles  on  the  grinding  face.  They  are  of  simple  and  primi- 
tive type,  and  indeed  are  most  like  the  molars  of  the  bears  and  other 
omnivorous  animals.  They  are  not  highly  specialized  like  those  of  the 
carnivora  on  the  one  hand  with  high  sharp  blades  for  cutting  flesh,  nor 
like  those  of  the  herbivora  on  the  other,  which  are  extended  laterally  for 
grinding  tough  vegetable  fibre.  They  are  of  low  organization  as  regards 
their  functional  development. 

The  molars  in  man  are  twelve  in  number,  three  on  each  side  of  each 
jaw,  and  are  placed  at  the  rear  of  the  arch,  opposite  the  strong  triturat- 


38  MACROSCOPTC  ANATOMY  OF   TIIF.    HTMAX   TKKTII. 

\uvr  muscles,  fur  the  ])urpose  of  cnisliiiiu'  and  masticating;  I'ood.  Thoy 
arc  im})ortant  factors  in  alimentation  and  contribute  to  the  function  of 
digestion  by  preparing  ibod  for  the  stomach.  Their  loss  imjiairs  this 
function  seriously  and  leads  to  derangement  of  the  stomach  by  over-tax- 
ing it  with  imperfectly  masticated  food-substances. 

15.  The  Upper  Molar. — The  typical  U])})er  molar  is  formed  by  the 
fusion  of  three  cones,  as  is  plainly  observed  in  the  three  roots  and  the 
three  tubercles  (Fig.  21,  A).  The  tricuspid  molar,  therefore,  is  a  jirimi- 
tive  form,  and  is  rarely  seen  in  man,  the  normal  form  being  quadritu- 
berculate.  The  fourth  additional  cusp,  the  disto-lingual  {b),  is  merely 
a  supplemental  cusp  added  to  the  crown.  An  upper  molar  is,  there- 
fore, composed  of  three  tubercles,  and  a  cingule  which  has  not  yet 
developed  a  root  to  support  it.  The  tritubereulate  molar  is  the  primitive 
form  of  this  tooth,  the  quadrituberculate  appearing  later,  and  is  found  in 
onlv  a  iew  liviup;  forms,  as  some  of  the  lemurs  and  the  insectivorous 
and  carnivorous  mammalia.  In  man  there  is  sometimes  a  reversion  of 
the  upper  molar  to  the  tritubereulate  form,  which  is  a  marketl  degeneracy 
in  the  form  of  this  tooth.  In  an  analysis  of  this  tooth,  therefore,  the 
mesio-buccal  tubercle  (c)  is  the  canine  cusp  ;  the  mesio-lingual,  the  bicus- 
pid cusp  [d) ;  the  disto-buccal,  the  molar  cusp  {e),  and  the  disto-lingual 
is  but  a  supplemental  cusp, — it  is  not  a  true  cusp,  as  it  has  no  root  to 
support  it. 

The  architecture  of  the  upper  molar  presents  some  interesting  features. 
We  observe  that  the  crown  is  in  a  general  way  a  geometrical  form,  a 
cube  (/),  wdien  perfect  and  symmetrical.  It  is  suggestive  of  symmetry, 
but  when  taken  with  the  root  form  is  not  quite  perfect,  for  it  is  sup- 
ported on  three  roots  instead  of  four  to  correspond  with  the  four  tuber- 
cles at  the  four  corners.  So  it  lacks  the  "  harmony  of  adequate  sup- 
port," which  is  a  cardinal  principle  in  architecture.  But  the  crown 
separately  is  a  symmetrical  form,  a  cube,  although  the  angles  are  rounded 
off  and  the  corners  and  ])oints  are  toned  down  and  not  acute.  We  no- 
tice that  there  are  four  strong  columns,  one  at  each  of  the  four  corners 
(fj).  They  are  connected  on  the  four  sides  by  the  marginal  ridges  acting 
as  strong  connecting  arches  (h).  These  arches  are  related  to  the  col- 
umns of  the  crown,  and  both  are  impressively  proportioned.  The  cusps 
may  be  likened  to  the  capitals  of  the  columns,  and  the  descending  mar- 
ginal and  triangular  ridges  to  the  cornice,  gathered  together  to  form  the 
capitals.  The  triangular  ridges  may  be  considered  girders  (i),  bind- 
ing the  four  together  and  also  bracing  the  square  obliquely.  Or,  the 
four  triangular  ridges  running  to  the  centre  may  be  regarded  as  half- 
arches  or  buttresses,  supporting  the  roof  vault, — the  grinding  face. 
Other  elements  could  be  marked  out  in  an  architectural  study  of  the 
crown  of  this  tooth,  showing  its  beautiful  design  and  symmetry. 


THE  MOLARS. 


39 


The  upper  first  molar  approximates  the  secoud  bicuspid  on  its  distal 
side.  There  is  a  marked  and  abrupt  change  in  form,  as  the  molar  has 
double  the  number  of  cusps  of  the  bicuspid, — being  formed  like  two 
bicuspids  fused  together.  The  four  tubercles  mean  an  extension  of  sur- 
face and  a  further  adaptation  to  functional  requirements.  The  crown 
is  laro-e  and  cubical  in  form,  and  more  or  less  rounded. 

Fig.  21. 


Architectural  diagram. 


The  upper  molar. 


The  buccal  face  (K)  is  wide  and  rounded.  It  is  twice  the  width  of 
the  bicuspids.  It  is  broadest  at  the  morsal  margin,  narrowing  upward  to 
the  cervix,  where  it  is  widely  rounded  or  arched.  A  vertical  depression, 
the  buccal  groove  (l),  extends  from  the  cervical  border  to  the  morsal 
margin,  dividing  the  face  into  two  oblong  rounded  eminences,  the  mesial 
and  distal  buccal  lobes  (m  m). 

The  lingual  face  (n)  is  more  rounded  than  the  buccal,  the  cervical  por- 
tion being  the  most  convex  (o),  the  mesial  and  distal  sides  being  depressed 
toward  the  single  lingual  root.  The  morsal  half  is  divided  by  the 
lingual  groove  (q),  which  descends  over  the  lingual  marginal  ridge  be- 
tween two  lobes,  the  mesial  (r)  and  distal  (jj),  which  are  usually  much 
rounded.  The  morsal  half  of  the  face  curves  toward  the  grinding  sur- 
face. The  mesial  lobe  sometimes  presents  the  lingual  cingule  (s),  a 
sort  of  fifth  tubercle  of  greater  or  less  size.  A  groove  branches  from 
the  lingual  groove  and  extends  over,  between  the  cingule  and  crown. 

The  mesial  face  (T)  is  flat  longitudinally,  descending  from  the  marginal 
ridge   to   the  cervix  in   a    nearly  straight  line.     Bucco-lingually  it  is 


40 


MACROSCOPIC  ANATOMY  OF  THE  HUMAN  TEETH. 


convex,  ncarlv  flat  at  the  marginal  ridge,  and  rounded  at  the  cervix, 
beino;  (l(>j)rcssed  toward  the  lingual  root.  Sometimes  a  depression  from 
the  hifui-cation  of  the  mesio-buceal  and  lingual  roots  extends  part  way 
up  on  the  face  {a). 

The  (Udal  face  is  similar  to  the  mesial  except  that  it  dips  more 
toward  the  cervix,  and  is,  perhaps,  more  rounded  toward  the  lingual 
root. 

The  morsal  surface  (Fig.  22)  is  the  most  important  part  of  this  tooth, 
and  shows  features  that  make  it  interesting  and  unique.     The  abrupt 


Fig.  2-2. 


d     h      j       c 

The  morsal  surface  of  the  upper  first  mular. 

change  from  the  bicuspid  form  is  notable,  for  there  are  presented  four 
cusps,  a  doubling  of  the  number ;  the  outline  of  this  face  presents  a 
square  form  with  tubercles  at  each  corner,  the  mesio-buccal  («),  the 
disto-buccal  (6),  the  mesio-lingual  (e),  and  the  disto-lingual  (d) ;  the  lat- 
ter is  erratic  and  may  be  either  pronounced  or  quite  reduced  in  size. 

There  are  four  marginal  ridges — the  mesial  (e),  buccal  (/),  distal  (g) 
lingual  (h),  the  oblique  (t),  and  the  four  triangular  ridges  (_/).  The  oblique 
ridire  connects  the  mesio-ling-ual  with  the  disto-buccal  tubercle  and  is 
really  the  remnant  of  the  marginal  ridge  of  the  tricuspid  molar  ;  the 
fourth  cusp,  the  disto-lingual,  being  raised  up  on  the  disto-lingual  side. 
The  four  triangular  ridges  descend  from  the  four  tubercles  toward  the 
centre  of  the  tooth,  the  oblique  ridge  being  formed  by  the  fusion  of  the 
triangular  ridges  of  the  mesio-lingual  and  disto-buccal  cusps. 

There  are  two  fossae  (A-),  one  mesial  and  the  other  distal  to  the  oblique 
ridge.  Sometimes  the  latter  is  cut  by  a  groove  or  sulcus  (/)  which 
extends  from  the  mesial  to  the  distal  fossa.  Sometimes  by  the  reduction 
of  the  disto-lingual  lobe  and  cusp,  the  mesial  fossa  is  extended  and 
becomes  central  to  the  crown.  A  groove  extends  from  the  mesial  fossa 
over  the  buccal  marginal  ridge  (hi)  quite  on  to  the  buccal  face,  dividing 
the  mesial  from  the  distal  buccal  lobes.  A  groove  also  extends  over 
the  lingual  marginal  ridge  (71)  down  upon  the  lingual  face,  dividing  the 
lingual  lobes.  When  this  groove  becomes  a  fissure,  caries  ensues  and 
the  disto-lingual  cingule  readily  breaks  away,  this  cingule  being  a  weak 
feature  in  the  mechanical  design  of  this  tooth ;  cutting  the  distal  mar- 
ginal ridge  also  weakens  this  cusp.     The  triangular  grooves  branch  from 


THE  MOLARS.  41 

the  two  fossse  on  to  the  cusps,  dividing  the  triangular  from  the  marginal 
ridges. 

The  neck  of  this  tooth  is  of  rounded  rhomboid  form  on  section  (o), 
widest  at  the  buccal  side.  The  enamel  is  almost  level  on  all  four  sides, 
dipping  downward  slightly  on  the  mesial  and  distal.  A  depression 
occurs  at  the  bifurcation  of  the  buccal  roots,  and  an  inward  inclination 
on  the  mesial  and  distal  sides. 

The  roots  are  three  in  number  (Fig.  21),  two  on  the  buccal  side, 
which  are  small  and  flat  or  round,  and  one  on  the  lingual  side,  which  is 
large  and  rounded.  The  roots  are  usually  separated,  but  may  be  found 
united,  by  a  septum  of  cementum,  in  various  directions.  The  mesio- 
buccal  root  is  the  larger  of  the  two  buccal  roots,  and  forms  a  second 
turning-point  or  spring  of  the  arch.  All  the  roots  are  slightly  bent 
and  may  be  very  crooked. 

The  pulp  chamber  branches  into  three  canals,  one  in  each  root.  The 
lingual  canal  is  large  and  open  and  is  readily  entered.  The  canals  of  the 
two  buccal  roots  are  small  and  fine,  and,  with  the  possibility  of  crooked- 
ness in  the  roots,  present  the  most  difficult  problems  as  to  treating  and 
filling  found  in  the  whole  denture. 

The  upper  second  molar  is  similar  to  the  first  in  some  respects  but 
very  diiferent  in  others.  It  is  rather  smaller,  is  not  usually  full  and 
square,  but  disposed  to  become  rhomboid  in  form  (Fig.  23,  o,  6),  by 
disto-mesial  compression. 

The  buccal  face  is  similar  to  that  of 
the  first  molar,  and  the  same  description 
will  apply  to  it.  If  any  difference  is 
found  it  is  that  the  face  is  strongly  com- 
pressed from  front  to  back,  and  the  disto- 
lingual  cusp  is  more  reduced  as  a  con- 
stant feature. 

The  linqual  face  (c)  is  diiferent  from  ^_,        ^  f    , 

•^  •^  ^   '  The  upper  second  molar. 

that  of  the  first  molar  in  that  by  the  sup- 
pression of  the  disto-lingual  tubercle  (d)  and  the  distal  lobe,  the  mesio- 
lingual  lobe  is  enlarged  so  that  it  occupies  the  entire  fiice,  which  is  full, 
rounded,  and  convex  (<').  It  is  rarely  divided  into  two  lobes  as  in  the 
first  molar,  owing  to  the  enlargement  of  the  mesial  lobe  and  the  pushing 
backward  of  the  oblique  ridge,  which  throws  the  lingual  groove  on  to 
the  disto-lingual  angle  {(I) ;  or  the  groove  may  be  absent  altogether. 

The  mesial  and  distal  faces  are  similar  in  form  to  those  of  the  first 
molar,  being  perhaps  more  flattened. 

The  morsalface  is  similar  to  that  of  the  first  molar,  except  that  the 
tubercles  are  less  pronounced  and  the  distal  ones  are  reduced  in  height 
to  accommodate    the  u])war<l    curve  of  the  line    of  occlusion    at  this 


42 


MACROSCOPIC  ANATOMY  OF  THE  HUMAN  TEETH. 


point.  The  disto-lingiial  ('1110:1110  is  smaller  than  that  iijxni  the  first 
molar,  and  is  often  barely  markcHl.  This  throws  the  oblique  ridge  more 
to  the  distal  side  and  enlarges  the  mesial  fossa.  The  various  grooves  are 
the  same  as  on  the  first  molar,  except  that  one,  the  lingtial,  may  be  lost. 

The  neck  is  less  regular  in  outline  than  that  of  the  first  molar,  as  the 
crown  varies  so  much  in  shape.  It  is  more  flattened  mesio-distally  and 
depressed  toward  the  roots. 

The  roots  are  the  same  in  number  and  general  form  as  in  the  first 
molar,  but  spread  less  and  are  more  irregular  in  form.  They  may  con- 
verge or  be  crooked,  or  may  be  fused  together.  This  makes  the  pulp 
canals  more  difficult  to  treat.  Sometimes  the  three  roots  are  completely 
fused,  as  in  the  third  molar,  and  the  canals  may  coalesce  ;  or  the  canals 
of  the  two  buccal  roots  may  run  into  one.  The  irregularity  and  uncer- 
tainty of  the  form  of  the  roots  make  this  tooth  difficult  to  deal  with  in 
treating  its  pulp  canals. 

16.  The  Lower  Molars. — The  lower  first  molar  ap])roximates  the 
lower  second  bicuspid  on  its  distal  side.  It  is  the  first  of  the  true  grind- 
ers of  the  lower  jaw  and  the  largest  tooth  in  the  dental  series.  Unlike 
the  upper  molars  the  transverse  diameter  is  less  than  the  mesio-distal. 
The  greater  width  is  found  across  the  base  of  the  disto-buecal  tubercle. 
The  crow'n  is  square  or  trapezoidal  in  form,  depending  on  the  size  of  the 
fifth  tubercle.  Being  quinquituberculate,  the  crown  is  broadened  by  the 
multicuspid  grinding  face.  The  buccal  face  is  inclined  toward  the  centre 
of  the  tooth,  for  its  morsal  half,  to  accommodate  the  occluding  teeth. 

Architecturally,  the  tooth  is  formed  of  four  cones  (Fig.  24,  .4),  and 


Architectural  diagram 
(1 


B 

The  lower  flrst  molar. 

mav  be  roughly  divided  into  four  quarters.     There  are  four  primitive 
cones  with  their  tubercles  and  one  cingule  in  the  structure. 


THE  MOLARS.  43 

The  morsal  surface  {B)  is  trapezoidal  in  outline,  the  buccal  line 
being  the  longest.  The  buccal  angles  are  acute,  while  the  lingual 
are  rounded  and  obtuse. 

There  are  five  tubercles,  two  on  the  lingual  margin  and  three  on  the 
buccal.  They  are  named  the  mesio-buccal  (c),  median  buccal  {d),  disto- 
buccal  {e),  disto-lingual  (/),  and  mesio-lingual  {g).  These  tubercles  are 
less  obtuse  and  more  rounded  than  those  of  the  other  grinding  teeth,  the 
mesio-buccal  usually  being  the  largest,  the  others  are  not  so  prominent, 
rarely  raised  and  sharp. 

The  ri(lf/es  are :  the  marginal  ridges — buccal,  distal,  lingual,  and 
mesial — and  the  five  triangular  ridges  descending  from  the  five  tuber- 
cles toward  the  centre  of  the  tooth. 

The  grooves  and  sulci  upon  the  morsal  surface  are  very  irregular.  A 
deep  sulcus  traverses  the  face  from  the  mesial  to  the  distal  marginal 
ridge.  A  groove  runs  off  toward  the  lingual  side,  dividing  the  lingual 
cusps  (i),  sometimes  cutting  the  lingual  marginal  ridge,  but  rarely 
reaching  over  on  the  lingual  face.  A  groove  runs  toward  the  buccal 
side,  dividing  the  mesio-buccal  from  the  median  tubercle  (/),  cutting 
the  marginal  ridge  and  extending  over  quite  on  to  the  buccal  face.  This 
groove  often  becomes  the  seat  of  caries  owing  to  the  enamel  structure 
being  faulty.  Another  groove  extends  toward  the  disto-buccal  angle  (^k), 
dividing  the  median  from  the  disto-buccal  tubercle,  and  rarely  extends 
over  on  to  the  buccal  face.  A  groove  may  extend  distally  cutting  the 
distal  marginal  ridge  (l),  and  one  mesially  cutting  the  mesial  marginal 
ridge  (/»),  but  these  are  not  usually  marked.  The  triangular  groove  run- 
ning up  on  each  side  of  the  triangular  ridges  («)  divides  these  from  the 
marginal  ridges.  Supplemental  grooves  may  divide  the  triangular  ridges 
again.  The  pits  at  either  end  of  the  sulcus  may  become  the  seat  of  caries 
through  faulty  formation. 

The  buccal  face  (C)  is  an  irregular  trapezoid  in  form,  the  morsal  margin 
being  longest ;  the  mesial  and  distal  sides  converge  toward  the  cervical 
border,  which  is  rounded.  The  morsal  margin  is  broken  by  the  three 
tubercles  rising  upon  it.  The  buccal  face  is  convex  in  all  directions, 
that  from  the  morsal  to  the  cervical  borders  being  the  most  marked 
owing  to  the  morsal  half  converging  toward  the  centre  of  the  tooth. 
The  buccal  groove  (o)  leading  over  from  the  morsal  face,  divides  the 
face  into  two  lobes  which  are  full  and  rounded.  Sometimes  the  disto- 
buccal  groove  cuts  off  another  lobe,  thus  making  three  lobes  on  the  buccal 
face.  These  grooves  sometimes  lead  to  the  cervical  border,  but  usually 
terminate  in  the  mi<ldle  of  the  face  in  a  pit,  which  may  become  the  seat 
of  caries  through  faulty  formation  of  the  enamel. 

The  Ungual  face  (d)  is  wide,  rounded,  smooth  and  convex,  rather 
straight  perpendicularly,  leaning  in  the  lingual  direction.     It  forms  a 


44  MACROSCOPIC  ANATOMY  OF  THE  HUMAN  TEETH. 

isharp  antilc  with  the  niorsal  surfhcc,  whicli  is  smMiiouiitrd  with  two 
tubercles.  Sometimes,  but  rarely,  tlie  lingual  groove  passes  over  on  to 
this  face. 

The  mesidi  and  disfdl  faccn  (.s)  are  wide  and  flattened  transversely, 
but  convex  vertically.  They  are  trapezoidal  in  outline,  the  morsal 
border  being  longer.  The  cervical  border  is  more  convex,  and  tlips 
toward  the  neck  of  the  tooth. 

The  neck  (t)  is  very  regular  in  outline  and  contour.  It  is  approxi- 
matelv  square  with  all  four  sides  depressed  in  the  centres.  The  mesial 
and  distal  are  depressed  at  the  origins  of  the  grooves  leading  down 
upon  the  roots  ;  the  lingual  and  buccal  are  depressed  at  the  bifurca- 
tion of  the  roots,  the  depression,  which  is  wide  and  deep,  extending  up 
on  to  the  neck,  especially  upon  the  buccal  side.  The  enamel  line  is 
quite  irregular,  dipping  down  on  the  lingual  and  buccal,  and  leading 
well  up  on  the  mesial  and  distal  sides. 

The  rootM  are  two  in  number,  placed  with  their  longer  diameter  trans- 
versely to  the  jaw.  They  are  wide  bucco-lingually,  and  flat  and  narrow 
disto-mesially,  being  situated  distally  and  mesially  to  the  crown.  The 
posterior  is  formed  of  the  two  posterior  cones,  and  the  anterior  of  the 
two  anterior  cones  {A).  This  is  plainly  shown  in  the  formation  of  the 
roots,  Avhich  are  grooved  both  distally  and  mesially,  and  in  the  tendency 
to  bifurcation,  which  sometimes  actually  occurs.  They  divide  close  to 
the  crown,  so  that  the  grooves  of  bifurcatiou  extend  well  up  on  the 
neck.  The  distal  root  is  thicker  and  more  rounded  than  the  mesial, 
the  latter  being  more  flattened,  with  the  grooves  deeper,  and  it  is  more 
often  bifurcated.     Both  are  deflected  from  the  median  line. 

The  pulp  canal  is  shaped  like  the  roots,  with  two  main  branches. 
The  distal  branch  is  the  larger,  being  round  and  open,  as  the  root  is  more 
rounded.  The  mesial  branch  is  flat  and  spindle-shaped,  being  difficult 
to  enter,  and  usually  having  two  sub-branches  following  the  buccal  and 
lingual  divisions  of  the  root.  These  sub-branches  are  small  and  hair- 
like and  troublesome  to  enter. 

The  lower  second  molar  (Fig.  25)  differs  from  the  first  in  many 
respects.  It  is  of  the  same  general  form,  but  is  more  quadrangular,  as 
it  has  but  four  tubercles.  It  is  more  rounded  and  symmetrical  than  the 
first,  the  four  cones  and  four  primitive  tubercles  being  well  marked. 
The  absence  of  the  fifth  tubercle  leads  to  most  of  the  differences  between 
the  second  and  the  first  molar. 

The  morsal  face  (c)  has  but  four  tubercles,  one  at  each  corner  of  the 
face,  differing  from  that  of  the  first  molar,  which  has  five.  The  fifth 
tubercle  rarely  appears  in  the  higher  races  of  mankind,  but  is  some- 
times found  in  the  low  and  savage  races,  and  occurs  regularly  in  the 
apes.     It  is  not  uncommon  in  the  negro,  but  is  absent  as  a   rule  in 


THE  MOLARS. 


45 


the  European  races.  The  tubercles  are  symmetrical,  rounded  and 
obtuse,  the  lingual  being,  however,  sharper  than  the  buccal. 

The  sulci  describe  a  cruciform  shape,  separating  the  four  tubercles 
symmetrically  from  each  other.  The  buccal  groove  sometimes  continues 
on  to  the  buccal  face,  rarely  to  the  lingual.  The  triangular  grooves 
run  up  on  the  morsal  triangular  ridges.  The  marginal  ridges  are  well 
marked,  the  mesial  and  distal  being  often  divided  by  grooves.  The 
triano-ular  ridges  are  usually  w^ell  marked,  leading  to  the  centre  of  the 
tooth.     They  are  full  and  strong. 

The  buccal  face  (d)  is  convex  and  of  more  regular  form  than  that 
of  the  first  molar.     It  is  divided   into  two  lobes  {e,  e)  by  the  buccal 


Fig.  25. 


h        h 
The  lower  second  molar. 


groove  {d),  which  is  rarely  deep.  A  pit  is  often  found  in  the  centre 
of  the  face,  which  may  become  the  seat  of  caries.  The  face  is  curved 
toward  the  centre  of  the  tooth,  as  in  the  first  molar. 

The  lingual  face  is  similar  to  that  of  the  first  molar,  but  may  be  more 
rounded  toward  the  morsal  l)order.  It  is  symmetrically  convex  in  both 
directions. 

The  )iic.-<ial  and  distal  faces  (f)  are  similar  to  those  of  the  fii'st  molar 
excei)t  tluit,  the  crown  being  smaller,  they  may  be  more  perpendicular, 
but  are  well  rounded. 

The  neck  (g)  is  more  regularly  formed  than  tliat  of  the  first  molar, 
the  margin  of  the  enamel  line  being  quite  as  irregular.  It  may  be  more 
constricted. 

The  roots  {h,  It)  are  similar  to  those  of  the  first  molar,  but  are  more 
rounded  in  shape,  are  usually  crooked,  and  on  that  account  difficult  to 
treat. 

The  jiidp  cancds  arc  similar  to  those  of  the  first  molar,  but  the  tend- 
ency to  crookedness  renders  treatment  quite  difficult.  The  direction 
of  irregularity  of  form  is  so  uncertain  that  no  rule  can  be  applied  to  it. 

17.  The  Third  Molars. — The  up])er  and  lower  third  molars  can  best 
be  described  together,  on  account  of  their  similar  eccentricities.  They 
are  verv  irregular  as  t(t  the  time  and  to  the  frecpiency  of  their  appearance 
in  civilized  man.     About  one-half  of  the  individuals  of  European  races 


46 


MACROSCOPIC  ANAT03n^  OF  THE  HUMAN  TEETH. 


The  upper  third  molar 


erupt  them  :>t  tlic  normal  |)('ri()(l,  /.  c.  seventecMi  to  twonty-one  year.'<  of 
ago.  Ill  oiu'-fourth  they  erupt  at  irregular  intervals  to  the  thirtieth 
vear,  and  in  the  remainder  they  may  appear  later,  or  the  first,  seeond, 
third,  or  all  o\'  them,  may  he  absent  altogether.  In  one  series  of  forty 
adult  skulls  observed,  twelve  had  one  or  more  absent.  The  absence  and 
other  erratic  peculiarities  of  these  teeth  sometimes  seem  to  be  hereditary 
and  can  be  traced  in  families  through  several  generations. 

This  tooth  is  often  reduced  in  size  and  may  be  a  mere  peg  (Fig.  26,  a). 
It  is  of  very  irregular  form  in  civilized  races,  but  is  as  large  and  as  well 

formed  as  the  other  molars  in  most 
a  b  d  e  races  low  in  the  ethnological  scale. 

The  contraction  of  the  jaws  through 
disuse  has  much  to  do  with  the  mal- 
development  of  this  tooth,  and  it  is 
often  so  cramped  for  room  as  to  pro- 
duce distressing  irritation  which  ne- 
cessitates its  removal.  Impaction 
and  malposition  of  the  third  molars  render  them  difficult  of  extraction 
and  are  the  fruitful  source  of  many  serious  lesions.  (See  the  chapter 
on  Extraction  of  Teeth.) 

The  upper  third  molar  is  more  or  less  similar  to  the  other  upper 
molars  when  perfect  and  well  developed,  but  it  is  very  erratic  as  to  form 
and  structure. 

This  tooth,  when  well  formed,  is  of  trituberculate  form  (b),  the 
disto-lingual  cingule  being  suppressed.  This  cingule  diminishes  grad- 
ually from  the  first  molar,  in  which  it  is  well  formed,  to  the  second, 
Mdiere  it  is  reduced,  then  to  the  third,  where  it  is  almost  or  entirely 
absent.  The  oblique  ridge  thus  becomes  the  posterior  marginal  ridge 
(c),  as  in  the  typical  trituberculate  molar.  The  three  tubercles  are 
reduced  and  rounded.  The  sulci  usually  degenerate  into  fissures,  as 
the  formation  of  this  tooth  is  notoriously  faulty.  The  enlarged  mesial 
fissures  thus  become  the  seat  of  extensive  caries. 

The  buccal  face  resembles  that  of  the  first  and  second  molars,  but  is 
more  rounded. 

The  lingual  face  (d)  is  full  and  rounded,  with  but  a  single  lobe,  owing 
to  the  reduction  or  absence  of  the  disto-lingual  tubercle. 

The  mesial  face  (e)  is  similar  to  that  of  the  second  molar,  but  reduced, 
and  the  dwtalface  is  round  and  short,  as  no  tooth  succeeds  it  in  the  rear. 
The  7ieck  is  constricted  and  tapers  toward  the  conate  roots.     It  is  of 
a  rather  rounded  triangular  shape. 

The  three  roots  of  the  upper  molars  are,  in  the  third,  usually  more 
blunt,  conate,  short  in  form,  and  may  curve  backward.  In  lower  races 
and  sometimes  in  individuals  having  strong  osseous  organizations,  the 


THE  MOLARS. 


47 


Fig. 


The  lower  third  mobir. 


t>'pical  three  molar  roots  are  found.  Sometimes  there  are  multiple 
roots,  which  are  likely  to  be  curved  iu  various  directions  and  may 
have  decided  hooks. 

In  the  large  conate  root,  the  pulp  canals  usually  coalesce,  but  in 
cases  in  which  the  root  is  divided  there  will  also  be  division  of  the 
pulp  chamber. 

The  lower  third  molar  is  similar  to  the  other  loAver  molars  in 
general  form  (Fig,  27,  u),  but  is  probably  not  so  erratic  and  not  subject 
to  such  extreme  variations.  The  crown  is 
quadrangular  in  section,  the  angles  rounded. 

On  the  morsal  face  [b),  there  are  four 
principal  tubercles  as  in  the  second  molar, 
but  this  may  be  supplemented  by  the  ex- 
tension of  the  disto-marginal  ridge  into  a 
cingule  or  heel  (c).  This  heel  is  rather 
erratic ;  it  may  be  large  or  small,  thus 
modifying  the  size  of  the  morsal  sur- 
face. Sometimes  the  face  is  wrinkled  and,  like  this  tooth  in  the 
orang  utan,  the  sulci  exhibit  the  cruciform  shape  similar  to  that  of  the 
second  molar.  The  many  grooves  leading  away  from  the  main  sulcus  may 
be  imperfect  and  become  the  seat  of  caries.  The  buccal  groove  running 
from  the  morsal  on  to  the  l)uccal  face  (a)  is  very  subject  to  imperfection. 

The  four  lateral  faces  are  similar  to  those  of  the  second  molar,  except 
that  the  distal  is  more  convex  and  full,  and  often  very  prominent  if  the 
fifth  cingule  is  well  developed. 

The  neck  is  of  similar  shape  to  that  of  the  second  molar. 

The  roots  are  similar  to  those  of  the  other  lower  molars,  but  generally 
smaller  as  compared  with  the  crown  (cl).  They  are  usually  divided  like 
the  others,  but  the  two  may  be  fused  together,  or  be  closely  opposed. 
In  either  case  they  are  usually  projected  distally  more  or  less,  leading 
backward  into  and  under  the  ramus,  thereby  rendering  extraction  of 
this  tooth  difficult  and  dangerous,  especially  where  the  maxilla  is  of 

Fig.  28. 


The  fourth  molar. 


dense  structure  or  where  there  is    impaction.     The  roots    are  usually 

more  rounded,  especially  the  distal  one,  than  those  of  the  other  molars. 

The  pulp  canah  are  generally  divided,  whether  the  root  is  or  not. 


48  MACROSCOPIC  ANATOMY  OF  THE  HUMAN  TEETH. 

As  the  roots  are   usually  crooked,  the    difliculty  of  euteriuo'    thcni   is 
increased,  as  the  canals  follow  the  form  of  the  roots. 

Fourth  molars  sometimes  ai)j)ear  as  supernumerarv  teeth,  and  are 
either  fused  to  the  uj)])er  tiiird  molar  in  a  variety  of  uncouth  forms 
(Fig-.  2<S,  (i)  or  erupt  separately  as  mei'e  pe_i>--shai)ed  teeth  between  the 
buccal  faces  of  the  second  and  third  molars  (h)  or  at  the  distal  aspect 
of  the  latter  tooth.  The  fourth  molar  rarely  appears  as  a  full  molar, 
c.\ce])t  in  some  of  the  large-toothed  races,  as  negroes,  Australians,  etc., 
and  then  usually  in  the  lower  jaw.  Among  the  negroes  in  Africa  the 
fourth  molar  is  sometimes  found  in  full  form  as  a  typical  molar. 

Fig.  29. 

•^^-  T  '  /• . 


Negro  jaw  with  fourth  molar. 


The  Deciduous  Teeth. 


IS.  The  DECIDUOUS  TEETH  are  those  which  appear  in  infancy  and 
serve  the  purpose  of  dental  organs  during  the  first  years  of  the  develo])- 
ment  of  the  individual,  until  the  jaws  and  their  environment  are  ready 
for  the  larger,  permanent  teeth  to  come  into  place.  They  bear  a  direct 
relationship  to  the  conditions  of  the  digestive  apparatus  and  the  food 
required  at  that  early  stage.  The  food  of  infancy  being  simple  and 
requiring  little  mastication,  the  deciduous  set  are  small  and  insufficient 
for  the  reduction  of  more  resisting  substances.  As  these  foods  come  to 
form  part  of  the  dietary,  the  larger  teeth  of  the  permanent  set  appear, 
and  perform  the  duties  of  higher  functional  activity. 

The  crowns  of  the  deciduous  teeth  resemble,  in  a  general  way,  those 
of  the  permanent  teeth  which  succeed  them,  except  the  deciduous 
molars  (Fig.  30,  a,  d),  which  are  very  different  from  the  bicuspids 
of  the  permanent  set  which  displace  them. 

The  incisors  of  both  jaws  precede  the  analogous  teeth  of  the  same 
series  of  the  permanent  set.  They  are  similar  in  form,  but  reduced  {b), 
and  do  not  have  the  main  features  so  characteristically  marked.  They 
are    infantile   in  form   and    function.       T!ie   roots   of  these    teeth    are 


THE  DECIDUOUS  TEETH. 


49 


resorbed  at  from  the  fifth  to  the  ninth  year,  when  the  permanent  incisors 
come  into  place,  beginning  with  the  lower  centrals. 

The  canines  (c)  of  both  jaws  are  still  more  reduced  from  the  strong, 


Fig.  30. 


The  deciduous  teeth. 


full  form  of  their  permanent  successors,  and  are  but  little  more 
specialized  than  the  incisors.  They  are  of  the  same  general  form  as 
the  permanent  canines,  but  much  less  developed. 

But  in  the  deciduous  molars  are  found  some  important  features 
which  mark  distinctive  differences.  They  are  of  true  molar  form  as 
compared  with  the  permanent  molars,  but  they  occupy  the  place  of  the 
bicuspids.  There  are  no  bicusjiids  in  the  deciduous  set,  the  molars  being 
of  full  molar  pattern  («,  d). 

The  deciduous  molars  of  both  jaws  are  of  irregular,  quadrangular 
form  on  the  morsal  surface,  diverging  rapidly  outward  to  the  neck, 
which  presents  a  large  buccal  ridge  standing  out  at  the  margin  of  the 
enamel,  and  is  rounded  off  suddenly  to  the  neck,  which  is  much  con- 
tracted. This  thick  ridge  is  characteristic  of  the  deciduous  molars  and 
is  absent  in  those  of  the  permanent  denture.  It  is  somewhat  more 
prominent  and  bulging  on  the  buccal  than  on  the  other  faces.  In 
adjusting  ferrule  crowns  to  these  teeth,  the  gold  need  not  be  carried 
beyond  this  ridge  but  burnished  over  it  slightly. 

The  morsal  surface  (e)  of  the  upper  deciduous  grinders  presents  the 
characteristic  pattern  of  the  upper  molars,  four  tubercles,  oblique  ridges, 
etc.,  but  reduced  and  contracted.  A  distinctive  feature  is  that  the 
marginal  ridges  and  angles  are  more  acute  and  sharp  than  in  the  per- 
manent molars.  Sometimes  the  two  lingual  cusps  are  reduced  to  one 
and  the  lingual  border  is  rounded  and  crescentic. 

The  second  molar  is  larger  than  the  first  and  the  morsal  surface  is 
wider. 

4 


50  MACROSCOPIC  ANATOMY  OF  THE  HUMAN  TEETH. 

The  transverse  diameter  of  the  crowns  of  the  upper  molars  is  tlie 
long;est. 

The  LOWER  MOLARS  ((/)  are  similar  to  the  ))ermaiient  molars  in  pat- 
tern, but  are  more  irregular  as  to  the  contour  of  the  morsal  surface  (/). 
The  tubercles  may  be  higher  than  in  the  upper  molars,  and  the  tri- 
angular ridges  more  marked.  The  (central  fossa  may  be  large  and  wide, 
or  divided  by  the  triangular  ridges.  The  second  molar  is  five-lobed, 
unlike  the  second  permanent  molar,  which  has  but  four  cusps.  The 
morsal  foce  is  d(H!idedly  trapezoidal  in  outline,  the  mesio-distal  diameter 
being  greater  than  the  transverse. 

The  roots  of  the  deciduous  molars  are  similar  to  those  of  th(>  other 
molars,  except  that  they  are  very  divergent  to  accommodate  the  crown 
of  the  advancing  bicuspids.  They  are  thin  and  long,  and  difficult  to 
enter  and  fill.  The  pulp  chamber  is  large  and  open  in  the  crown ;  as 
a  consequence  of  this  caries  soon  reaches  the  pulp.  Treatment  and 
filling  of  the  canals  is  difficult  and  uncertain. 

The  Variations  of  Tooth  Forms. 

19.  The  teeth  may  vary  quite  extensively  from  the  typal  forms  which 
have  been  described,  and  these  variations  may  be  due  to  a  number  of 
causes.  Through  all  degrees  of  variation,  however,  the  type  is  still  pre- 
served, unless  the  tooth  form  is  quite  destroyed  by  pathological  causes. 

The  general  causes  of  variation  may  be  enumerated  as  follows  : 

(1)  Incompleteness  of  development. 

(2)  Reversion  to  primitive  types. 

(3)  Temperamental  impress. 

(4)  Pathological  lesions. 

(1)  Under  incompleteness  of  development  may  be  grouped  all 
those  varieties  of  stunted  growth  which  are  the  eifect  of  disuse  and 
the  consequent  effi^rt  of  Nature  to  reduce  and  suppress  the  teeth  as 
useless  parts.  The  third  molar  teeth  suffer  most  from  these  suppressive 
attempts  of  Nature  in  the  effort  toward  economy  of  growth  ;  next  to 
these  teeth,  the  upper  lateral  incisors  are  most  frequently  affected  by 
reduction  of  size,  stunted  growth  and  sup})ression.  Other  teeth  are 
rarely  affected,  or  but  very  slightly,  by  this  influence,  except  in  rare 
cases. 

(2)  Under  the  second  head,  reversion  to  primitive  types,  we  have  a 
variety  of  interesting  phenomena  in  the  form  of  parts  of  the  human 
teeth  which  seem  to  be  a  zoological  legacy.  These  consist  of  conspic- 
uous features  which  reappear  and  seem  to  recall  forms  of  the  teeth 
observed  in  some  of  the  lower  animal  orders,  especially  the  quadrumana 
and  insectivora. 

Among  these  features  may  be  mentioned  the  curved  upper  central 


THE   VARIATIONS  OF  TOOTH  FORMS.  51 

incisor  with  the  prominent  cingule  on  the  lingnal-buccal  ridge,  making 
a  notch  which  recalls  the  incisors  of  the  moles  ;  the  prominent  cingule 
on  the  lingual  face  of  the  lateral  incisor,  which  is  not  uncommon  and 
recalls  the  form  found  in  the  insectivora  and  some  of  the  quadrumana ; 
the  extra-long,  curved  canine,  Avith  extra-large  median  ridges,  which 
recalls  the  large  forms  of  this  tooth  in  the  baboons  and  in  the  car- 
nivora ;  the  double  root  sometimes  found  in  this  tooth  is  also  a  re- 
version to  the  insectivorous  type  ;  the  three-rooted  bicuspid  is  a  quad- 
rumanous  reversion  ;  the  upper  tricuspid  molar  is  a  primitive  typal 
form,  leading  back  to  the  lemurs  and  beyond  them  to  the  early  typal 
mammals  found  in  fossil  formations  ;  the  notched  and  grooved  incisor 
recalls  the  divided  incisor  of  the  Galeojuthecus  ;  the  double-rooted  lower 
incisors  and  canines  recall  insectivorous  forms  ;  the  unicuspid  lower 
first  bicuspid  is  an  insectivorous  type  and  is  often  quite  marked  in  man  ; 
the  fifth  cusp  on  the  lower  second  molar  is  a  quadrumanous  rever- 
sion ;  the  wrinkled  surface  of  the,  lower  third  molar  is  like  that  of  the 
orang. 

There  are  other  features  that  might  be  named  illustrating  the  work- 
ings of  the  law  of  atavism,  by  which  parts  once  lost  in  evolution  may 
reappear  and  be  reproduced. 

(3)  Under  the  third  head,  temperamental  impress,  may  be  noticed 
those  differences  of  form  and  structure  which  have  relation  to  the  domi- 
nant temperament  in  the  constitution  of  the  individual.  Great  differ- 
ences exist  between  the  teeth  of  different  persons,  and  these  are  mainly 
dictated  by  temperament. 

The  teeth  of  the  primary  basal  temperaments  present  the  following 
physical  peculiarities,  which  are  characteristic  of  the  particular  tempera- 
ment : 

The  BILIOUS  TEMPERAMENT  presents  teeth  that  are  of  a  strong 
yellow ;  large,  long,  and  angular,  often  with  transverse  lines  of  forma- 
tion, without  brilliancy,  transparency,  and  of  but  slight  translucency ; 
firm  and  close  set  and  well  locked  in  articulation. 

The  SANGUINE  TEMPERAMENT  has  teeth  that  are  symmetrical  and 
well  proportioned,  with  curved  or  rounded  outlines,  and  round  cusps  ; 
cream  color,  inclined  to  yellow,  rather  brilliant  and  translucent ;  well 
set,  and  occlusion  firm. 

The  NERVOUS  TEMPERAMENT  has  teeth  Avhich  are  rather  long,  the 
cutting  edges  and  cusps  long  and  fine ;  color  pearl-blue  or  grav,  very 
transparent  at  the  apex  ;  the  occlusion  very  penetrating. 

The  LYMPHATIC  TEMPERAMENT  presents  teeth  that  are  pallid  or 
opaque,  dull  or  muddy  in  coloring ;  large,  broad,  ill-shaped,  cusps  low 
and  rounded  ;  the  occlusion  lose  and  flat. 

Of  the  binary  combin((fions  - 


52  MACROSCOPIC  ANATOMY  OF  THE  HUMAN  TEETH. 

The  SANGUiNEO-iuiJOiis  has  teeth  whicli  arc  Xay^o,  with  strong;  edges 
and  hirge  cusps  ;  color  dark  yellow,  and  quality  good. 

The  NERVO-BiLious  has  teeth  that  are  long  and  narrow,  with  l<^ng 
cusps  ;  color  yellowish  or  bluish  or  both  combined  ;  the  enamel  strong, 
the  dentin  soft. 

The  i.YMPiio-BiLious  has  teeth  that  are  large,  with  thick  edges  and 
short  thick  cusps  ;  yellowish  in  color ;  enamel  of  good  structure  and 
polish,  and  dentin  fair. 

The  BiLio-SAN(JUiNE()US  has  teeth  of  average  size,  round  arch,  well- 
developed  cusps  and  edges  ;  ri(;h  dark-cream  color ;  excellent  in  (piality. 

The  NERVO-SANGUINEOUS  has  teeth  of  average  size,  good  shape,  round 
arch,  good  edges  and  cusps  ;  rich  cream  color ;  enamel  and  dentin  of 
excellent  structure. 

The  LYMPHO-SANGUINEOUS  has  teeth  of  more  than  average  size, 
shapely  edges  and  cusjjs,  rounded  arch  ;  color  grayish  cream  ;  enamel 
and  dentin  fairly  good. 

The  BiLio-NERVOUS  lias  teeth  variable  in  size  and  form,  sometimes, 
broad,  again  very  long  with  more  pointed  and  long  cusps ;  the  color 
generally  bluish  ;  enamel  fairly  good,  dentin  soft  and  sensitive. 

The  SANGUINEO-NERVOUS  has  teeth  of  average  size,  good  shape, 
round  arch  ;  color  grayish  blue ;  soft  and  frail. 

The  BiLio-LYMPHATic  has  teeth  usually  large,  with  thick  edges, 
short  thick  cusps,  and  flat  arch  ;  color  yellowish ;  quality  good. 

The  SANGUiNEO-LYMPHATic  lias  teeth  of  more  than  the  average  size, 
broad  round  arch  ;  color  gray  ;  enamel  and  dentin  poor. 

The  NERVO-LYMPHATic  lias  teeth  of  average  size,  good  shape,  aver- 
age length,  rather  round  arch  ;  color  bluish  gray ;  soft  and  poor. 

Combinations  of  the  binary  temperaments  are  of  the  most  common 
occurrence  in  individuals,  but  there  is  usually  one  basal  temperament 
that  preponderates  over  the  others  and  gives  its  characteristic  to  the 
teeth  as  a  predominating  influence. 

(4)  Under  the  fourth  head,  patholog-ical  lesions,  are  to  be  included 
all  those  disturbances  of  nutrition  which  eventuate  in  faulty  formation 
of  the  teeth,  whether  due  to  specific  hereditary  diseases,  mere  malnutri- 
tion, idiosyncrasies,  predispositions,  defective  functional  life,  etc.  But 
this  leads  beyond  the  province  of  this  chapter  into  the  field  of  special 
pathology. 


CHAPTER   II. 

THE  EMBRYOLOGY  OF  THE  DENTAL  TISSUES. 

By  R.  R.  Andrews,  A.  M.,  D.  D.  S. 


A  CLEAR  understanding  of  the  minute  structure  of  the  teeth  can  only 
be  had  through  a  study  of  the  complex  processes  through  which  the 
tissue  elements  have  had  their  origin  or  have  derived  their  forms. 
The  teeth  do  not  belong  to  the  bony  skeleton  of  the  body,  but,  like 
the  hair,  nails,  etc.,  are  parts  of  the  dermal  system. 

The  origin  of  the  tissues  of  the  teeth  is  from  two  of  the  three 
germinal  layers  of  the  blastoderm,  the  epiblastic  and  mesoblastic  layers. 
A  transverse  section  through  the  blastoderm  of  a  chick  shows  that  the 
epiblast,  or  outer  layer,  is  formed  of  cells  like  columnar  epithelium ; 
their  shape  is  probably  due  to  lateral  pressure  of  adjoining  cells.  It 
is  from  this  layer  that  epithelium  is  formed,  and  epithelial  tissue  is  the 
origin  of  the  enamel.  The  mesoblast,  or  middle  layer,  is  composed  of 
cells  said  to  be  derived  from  both  hypoblast  and  epiblast,  but  princi- 
pally from  the  latter.^  They  are  merely  nucleated  structures,  containing 
granules,  the  nuclei  of  the  future  cells  of  the  connective  tissues.  In  this 
state  they  have  no  cell-limit  or  wall ;  as  they  grow  older  they  accumu- 
late around  themselves  formed  material.  Only  in  maturer  stages  do 
these  cells  develop,  on  their  surfaces,  an  optically  distinct  membrane 
or  other  structure.  It  is  from  the  cells  of  the  mesoblast  that  the  em- 
bryonic connective  tissue  which  forms  the  dentinal  papilla  originates. 

Development  of  the  Jaws. 

As  stated  by  Prof.  Sudduth,^  the  first  indication  of  the  formation  of 
the  oral  cavity  is  seen  very  early  in  the  life  history  of  the  embryo. 
The  superior  maxilla  arises  from  three  separate  points  :  on  either  side 
of  the  embryonic  head  a  process  springs  from  the  first  pharyngeal  arch. 
The  processes  pass  downward  and  forward,  and  unite  with  the  sides  of 
the  nasal  process.  From  the  frontal  prominence,  the  third  process,  the 
incisive,  grows  downward  and  fills  in  the  space  between  the  ends  of  the 
two  preceding  processes.  By  a  union  of  these  three  processes  the  supe- 
rior maxillse  are  completed.  The  inferior  maxilla  is  formed  by  buds 
growing  from  the  first  pharyngeal  arch ;  these  buds  grow  rapidly  until 

'  The  three  layers  of  tlie  blastoderm  are  also  designated  as  ectoderm,  mesoderm,  and 
entoderm  respectively. 

'^  American  System  of  DentiMry,  vol.  i.  p.  550. 

53 


54  EMBRYOLOGY  OF  THE  DENTAL   TISSUES. 

union  occurs  at  the  median  line.  The  central  portion  of  the  arch  thus 
formed,  very  soon  after  the  union  of  the  two  lateral  })rocesses,  becomes 
differentiated  into  a  cartihifjinous  cord  or  band,  which  serves  to  strengthen 
the  embrv(mic  jaw.  This  is  Meckel's  cartilage.  It  is  formed  of  two 
})arts  arising  from  the  mallei  of  the  ears  and  traversing  both  sides  of  the 
embvronic  jaw  to  the  point  of  union.  While  the  jaw-bone  is  forming, 
Meckel's  cartilage  disappears  by  absorption  ;  some  authorities  believe  it 
becomes  ossified,  forming  part  of  the  inferior  maxilla. 

The  Embryonic  Mucous  Membrane. 
If  at  a  time  just  previous  to  tooth  formation  a  section  across  the 

lower  jaw  is    cut,  it  will   be  found    to  consist  of  a  central    mass  of 

embryonic  connective  -  tissue  cells 
edged  on  every  surface  by  the  in- 
nermost layer  of  the  epithelium. 
This  covering  of  epithelium  is  the 
Malpighian  or  mother  layer,  most 
important  to  the  dental  histologist, 
because  from  it  originate  the  en- 
amel organs  of  the  teeth,  as  well  as 
'  the  bulbs  of  the  hair  and  the  epi- 
thelium of  the  glands.  Thus  early 
the  Malpighian  layer  consists  of 
cells  somewhat  like  those  of  the 
connective   tissue    within,  but  they 

Section  of  jaw,  embryo  of  pig,  showing  the      stain   more    deeply   and   are   really 

appearance  of  mucous  membrane  before  ^ithclial    CClls,    having   their    origin 

the  formation  of  the  enamel  organ :  1,  epi-  r  '  fe  & 

thelium ;  2,  stratum  Malpighii ;   3,  embry-  from  the  Cclls  of  the  Cpiblast.      This 

onic  connective  tissue.  tv  r   i    •    i  •  i 

Malpighian    layer   is,  again,  every- 
where covered  by  epithelial  cells,  which  are  continually  formed  by  it. 

When  the  tissue  is  older,  the  cells  of  the  stratum  Malpighii  become 
columnar  or  prismatic  in  shape,  standing  somewhat  vertically  over  the 
emV)rv()nic  tissue  beneath.  They  have  large  round  nuclei,  and  some 
authors  have  stated  that  they  have  no  cell-wall.  Just  without  these 
are  larger  cells,  sometimes  called  youthful  cells,  and  external  to  these 
the  cells  are  larger  and  are  more  polygonal  in  form,  representing 
the  cells  in  their  middle  life,  in  which  the  cell-wall  has  increased  in 
thickness,  while  the  nucleus  is  found  to  be  smaller.  Those  cells  on 
the  outer  surface  are  the  aged  cells,  consisting  almost  wholly  of  formed 
material.  They  in  time  lose  their  vitality,  having  undergone  changes, 
until,  from  the  fresh  mass  of  protoplasm,  they  finally  become  thin,  lifeless 
scales,  which  in  adult  tissue  are  constantly  cast  off  during  the  life  of  the 
individual.    They  are  reproduced  from  the  cells  of  the  stratum  Malpighii. 


THE  DENTAL  RIDGE  AND  DENTAL   GROOVE.  55 

Fig.  32. 


Section  of  jaw,  embryo  of  pig,  showing  the  epithelium  highly  magnified:  1,  oldest  epithelial 
cells ;  2,  the  younger  cells ;  3,  the  infant  layer,  the  stratum  Malpighii ;  4,  the  embryonic  connec- 
tive tissue. 

The  epithelium,  as  has  been  stated,  is  derived  from  tlie  epiblast,  and 
is  developed  considerably  earlier  than  is  the  embryonic  connective  tis- 
sue beneath. 


The  Dental  Ridge  and  Dental  Groove. 
On  that  portion  of  the  jaw  which  is  to  become  the  alveolar  border, 


between  the  fortieth  and  forty-fifth  days, 
there  is  seen  a  growth  of  cells,  which  looks 
as  though  it  had  been  pushed  up  in  the 
form  of  a  smooth  ridge.  If  a  section  is 
cut  across  the  jaw  at  this  time,  and  exam- 
ined, it  will  be  found  that  this  ridge  con- 
sists of  a  mound  of  epithelial  cells  which 
some  writers  have  called  the  maxillary 
rampart.  This  growth  of  cells  is  seen  to 
have  had  a  more  energetic  growth  inward 
into  the  substance  of  the  embryonic  tissue 
tlian  it  has  had  outward,  so  that  a  groove 
containing  epithelium  is  formed  around  the 
entire  upper  border  of  the  jaw,  and  in  this 
condition  has  been  called  the  tooth  band. 


Fig.  33. 


Section  thr<.ui,'h  ilic  jaws  of  human 
embryo,  showing  developing  en- 
amel organs.  (Section  by  Dr. 
Sudduth.) 


56 


EMBRYOLOGY  OF  THE  DENTAL   TISSUES. 
Fig.  34. 


.Hf^" 


Section  of  lower  jaw,  embryo  of  pig,  sliowing  lliu  lirsl  i^tage  of  growth  in  enaniel  organ  :  1,  epithe- 
lium ;  2,  stratum  Malpighii ;  3,  dental  groove ;  4,  commencing  growth  of  temporary  enamel 
organ  ;  5,  Meckel's  cartilage ;  6,  forming  bone  of  jaw.    (Section  by  Dr.  Sudduth.) 

The  cells  of  the  layer  next  the  embryonic  connective  tissue  are  always 
more  or  less  columnar.  They  are  directly  derived  from,  and  are  a  part 
of,  the  stratum  Malpighii.     It  was  the  loss  of  this  epithelial  tissue,  per- 

FiG.  35. 


Section  of  jaw,  embryo  of  pig,  showing  growth  of  enamel  organ:  1,  epithelium:  2,  stratum 
Malpighii :  3,  first  stage  in  growth  of  enamel  organ  of  temporary  tooth  ;  4,  embryonic  connec- 
tive tissue ;  5,  developing  bone  of  jaw. 


THE  DENTAL   RIDGE  AND  DENTAL    GROOVE. 
Fig.  36. 


5? 


1- 


'm' 


,...'■3^^ 


Section  of  jaw,  embryo  of  pig,  showing  growth  of  enamel  organ:   1,  cpitlielium;  2,  Malpighian 
layer:  3,  second  stage  in  growth  of  enamel  organ  :  4,  embryonic  connective  tissue. 


^^1^^ 


"-:-i 


Section  of  jaw , 


.i.rvi.  .1  |ii-,  -iio\\:;i_-  _■;.'«  Ill  ^.1  .  iiainil  nr-an:  1,  epithelium ;  2,  second  stage 
in  growth  of  enamel  organ  ;  <i,  embryimic  connective  tissue. 


58 


EMBRYOLOGY  OF  THE  DENTAL   TISSUES. 


r 


iMC.   3S. 


..•.«:•" 


**^ 


"^ 


-51 


>^fB| 


Section  of  jaw,  embryo  of  pig,  showing  growth  of  enamel  organ  and  zone  of  dentin-forming 
tissue :  1,  epithelium  ;  2,  enamel  organ  ;  3,  zone  of  dentin-forming  tissue. 

Fig.  39. 


1 

•^                                   ^       *     1*       , 

^ 

,^ 

JHj 

■j^^^s 

M 

'^J 

■    ! 

Section  of  jaw,  embryo  of  pig,  showing  growth  of  enamel  organ  and  first  stage  in  growth  of  dentin 
germ :  1,  epithelium  ;  2,  enamel  organ  ;  3.  dentin  germ.  (The  enamel  organ  has  been  pushed 
away  from  the  dentin  by  the  knife  in  cutting  the  section,  leaving  a  space  between  the  two.) 


THE  DENTAL   ETDGE  AND  DENTAL    GROOVE. 


59 


haps  by  the  action  of  too  powerful  reagents,  which  led  Goodsir  and  his 
followers  to  describe  the  appearance  of  an  open  groove.  The  Goodsir 
theory  had  no  foundation  in  fact,  because  no  such  open  groove  ever 
existed  in  that  situation. 

The  various  foldings  found  in  embryonic  tissue  no  doubt  are  an  ex- 
pression of  an  economic  provision  on  the  part  of  Nature  in  caring  for 

Fig.  40. 


Section  of  jaw,  embryo  of  sheep,  showins;  sr.iwth  of  enamel  orc^an  and  dentin  germ:   1,  large 
mass  of  epithelium  ;  '1,  enamel  organ  ;  3,  dentin  germ  ;  4,  growing  jaw. 


the  tissue  that  is  to  be  taken  up  by  the  expansion  of  the  parts  during 
its  growth,  as  eventually  they  are  all  smoothed  out.  Rose's  models^ 
show  that  the  original  inflection  (stratum  Malpighii)  at  an  early  stage 
divides  into  two  portions,  one  of  which,  the  outer,  is  nearly  perpen- 
dicular and  is  intimately  connected  with  the  formation  of  the  lip 
furrow,  whilst  that  immcHliately  under  consideration  passes  almost 
horizontally  backward  into  the  tissue  beneath. 

At  about  the  forty-eighth  day,  from  the  lingual  side  of  this  groove, 
at  a  point  where  a  tooth  is  to  be  formed,  a  portion  of  the  stratum 
Malpighii  is  found  growing  into  the  embryonic    connective  tissue,  in 

^  Models  of  Developing]  Teeth  and  Jaws.     By  Carl  Rose,  M.  D. 


60 


EMBRYOLOGY  OF  THE  DENTAL    TISSUES. 


shape  somewhat  like  a  bud,  and  this  is  the  first  indication  that  a  tooth 
is  to  be  developed — the  commencing  growth  of"  the  enamel  organ. 
This  ingrowth  increases,  and  assumes  the  sha])e  of  a  tubular  gland, 
pushing  its  way  into  the  connective  tissue.  It  may  now  be  called  an 
EPITHELIAL  CORD,  and  at  the  end  farthest  from  the  epithelium  proper 
a  growth  of  cells  takes  place,  this  part  ex))anding  from  the  multi])lica- 
tion  of  cells  within,  which  causes  it  to  assume  the  form  of  a  Florentine 
flask. 

Just  at  this  time,  at  a  point  somewhere  between  this  ex])anding  ])art 
and  the  Malpighian  layer  above,  a  budding  takes  place  from  this  cord, 
which  is  the  commencing  growth  of  the  enamel  orrjan  of  the  permanent 
tooth.  A  change  is  taking  pkice  in  the  embryonic  tissue  just  under  the 
flask-shaped  enamel  organ  ;  a  very  active  growth  of  cells  is  seen  to  be 


Via   41, 


Section  of  jaw,  embryo  of  pis,  showing  growth  of  enamel  organ  and  deutiii  germ :   1,  enamel 
organ  ;  2,  dentin  germ  ;  3,  growth  of  jaw  ;  4,  tongue. 

going  on,  and  this  activity  results  in  the  formation  of  a  pa])iUa,  the  first 
stage  in  the  growth  of  the  dentin  germ. 

As  the  enamel  organ  enlarges  by  an  increase  of  cells  within  it,  the 
borders  of  its  base  grow  inw^ard,  covering  the  dentinal  papilla  like  a 
cap  or  hood,  enclosing  it  at  its  base.  The  cells  within  the  enamel 
organ  are  seen  to   have   changed  ;    they  are  no  longer  like  epithelial 


THE  DENTAL  RIDGE  AND   DENTAL   GROOVE. 


61 


formations,    but    form    a   reticulum   and   have   a   stellate    appearance 
when  seen  in  section. 

While  the  change  in  form  of  the  central  cells  of  the  enamel  organ  is 
tiiking  place,  the  dentin  germ  is  assuming  the  form  of  the  future  tooth- 
point.     From  the  base  of  the  dentin  germ,  connective  tissue  is  being 


Section  of  jaw,  embryo  of  pig,  showing  fU 


i(i.  lary  molar  tooth  :  1,  enamel  organ  ; 


I,  dentin  germ. 


formed  around  the  enamel  organ,  like  the  outer  walls  of  a  bag,  this 
laver  beino;  the  wall  of  the  dental  sacculus  ;  and  when  the  enamel 
organ  is  nearly  enclosed,  the  epithelial  cord  that  connects  it  with  the 
INIalpighian  layer  breaks  up  into  epithelial  clusters ;  some  of  which 
wander  toward  the  INIalpighian  layer,  while  others  cluster  to  the  wall 
of  the  sacculus,  where  it  is  supposed  they  become  absorbed.  In  their 
origin  the  sacculus  and  dentin  germ  are  identical,  springing  as  they  do 
from  the  embryonic  connective  tissue. 

At  this  time  there  is  no  evidence  of  a  basement  membrane.  When 
the  enamel  organ  and  dentin  germ  become  enclosed  in  the  sacculus,  it 
and  its  contents  become  the  dental  follicle,  at  which  period  calcifica- 
tion is  about  to  commence. 


62 


EMBRYOLOGY  OF  TlIK  DENTAL    TISSUES. 


li] 


'\ 


k 


Section  of  jaw,  embryo  of  pig,  show  in^ 


'1(\  rldpmcnt  (if  temporary  molar  tooth  :  1,  enamel  organ  ; 
:J,  dentin  germ. 


The  Enamel  Organ. 

The  enamel  organ  is  now  in  its  perfected  state.  On  examination 
it  is  found  to  be  composed  of  three  distinct  celhilar  forms.  The  essen- 
tial layer  is  the  ameloblastic  layer  of  columnar  cells  which  rests  upon 
the  dentin  germ.  These  are  the  cells  that  are  to  become  the  enamel 
cells  or  ameloblasts.  They  have  become  changed  by  pressure  into  very 
symmetrical  hexagons,  four  or  five  times  as  long  as  they  are  broad,  with 
a  distinctly  marked  nucleus  in  the  part  farthest  away  from  the  dentin 
germ.  Only  the  sides  of  the  cells  are  said  to  have  membranes  :  they 
are  without  covering  at  either  end.  These  cells  are  longer  just  over  the 
point  of  the  dentin  germ  and  are  shorter  as  they  approach  its  base,  being 
here  very  mucli  like  those  of  the  outer  layer,  the  external  epithelium  of 
the  enamel  organ. 

This  outer  layer  is  composed  of  cells  which  are  roundish,  a  little 
longer  than  they  are  wide,  and  seem  to  be  losing  their  columnar  form. 
Indeed,  soon  after  calcification  has  commenced  these  cells  disappear.^ 

^  It  is  a  question  what  becomes  of  them.  Some  authorities  think  that  they  are  the 
origin  of  Nasmyth's  membrane,  but  this  is  very  doubtful,  for  investigation  shows  that 


THE  ENAMEL   ORGAN. 


63 


Just  within  these  two  epithelial  layers  there  is  found  the  second  im- 
portant layer  of  cells,  and  this  layer  has  been  named  the  stratum  inter- 
medium (see  Fig.  55).     The  cells  of  this  layer  are  intermediate  in  shape 


Fig.  44. 


Section  of  jaw,  embryo  of  pig,  showing  development  of  dental  follicle  and  first  stage  in  the  growth 
of  the  permanent  enamel  organ;  also  the  formation  of  walls  of  the  saceuhis  :  1,  epithelium  ; 
2,  Malpighian  layer ;  3,  enamel  organ  ;  4,  dentin  germ  ;  5,  outer  wall  of  sacculus ;  6,  inner  wall 
of  sacculus ;  7,  bud  of  enamel  organ  of  permanent  tooth ;  8,  growing  jaw. 

between  the  ameloblasts  and  those  of  the  stellate  reticulum.  The  layer 
was  first  described  by  Hanover,  and  is  thought  to  be  a  supplying  and 
nourishing  layer  to  the  ameloblasts.  Over  these  they  remain,  while 
everywhere  else  they  disappear  as  calcification  progresses.  It  is  prob- 
able that  they  give  birth  to  new  enamel  cells  as  the  circumference  of  the 
enamel  layer  increases  by  growth.  By  careful  examination  it  will  be 
found  that  they  are  connected  by  minute  processes  with  the  enamel  cells 
and  also  with  the  stellate  cells  of  the  central  portion.  Dr.  Lionel  Beale 
first  made  the  statement  that  a  vascular  network  lies  Avithin  the  stratum 
intermedium.     This  fact  has  recently  been  confirmed  by  other  English 

they  are  completely  lost  some  time  before  the  comj)letion  of  the  calcilication  of  the  enamel. 
Just  after  a  layer  of  dentin  has  been  formed,  everywhere  upon  its  surface  are  seen  the 
enamel  cells,  ready  to  form  the  enamel,  and  no  trace  of  the  outer  epithelium  can  be  seen. 
It  has  disappeared  from  tliat  part  in  the  perfected  enamel  organ. 


64 


EMBRYOLOGY  OF  THE  DEM'AL   TISSUES. 


workers,  for  Tomes  mentions  the  fact  that  Prof.  Howes  and  Mr.  Poulton 
have  demonstrated  this  vascular  network  in  the  stratum  intermedium 
of  the  enamel  org;an  of  tlie  rat. 

Dr.  J.  Leon  Williams,  in  an  article  on  "  The  Formation  and  Struc- 
ture of  Dental  Enamel,"  '  demonstrates  with  his  photo-microin^rajjhs  the 
existence  of  this  vascular  network  in  the  stratum  intermedium  of  the 
rat  which  had  been  previously  seen  by  these  English  observers,  but  it 
is  to  be  remembered  that  this  vascular  network  forms  after  the  outer 

Fig.  4-5. 


-^ 


\ 


Section  of  jaw,  embryo  of  pig,  showing  development  of  dentin  germ  and  enamel  organ  of  per- 
manent tooth  :  1,  epithcliuui ;  2,  euaiuel  organ ;  3,  dentin  germ  ;  4,  budtiiug  of  enamel  organ 
of  permanent  tooth ;  5,  developing  jaw. 

portions  of  the  enamel  organ  have  disappeared,  and  only  when  the  con- 
nective tissue  of  the  jaw  is  in  contact  with  the  cells  of  the  stratum 
intermedium. 

The  third  form  of  cells  fills  up  the  central  portion ;  they  appear 
star-shaped,  and  have  been  called  the  stellate  reticulum  of  the  enamel 
organ.  Between  the  cells  is  to  be  found  a  fluid  rich  in  albumin  ;  the 
consistence  of  this  is  somewhat  like  a  jelly ;  indeed,  enamel  organs 
have  been  called  enamel  jelly  or  enamel  pulps.  Tomes  states  that  the 
function  and  destination  of  the  stellate  reticulum  is  not  very  clear. 
Enamel  can  be  very  well  formed  without  it,  as  is  seen  among  reptiles 
'  Dental  Cosmos,  February,  1896. 


THE  EX  A  MEL   ORGAN.  65 

and  fish,  and  even  in  mammalia  it  disappears  prior  to  the  completion  of 
the  enamel.  It  has  been  supposed  to  have  no  more  important  function 
than  to  till  up  the  space  subsequently  taken  up  by  the  growing  tooth. 
Kolliker  does  not  agree  with  this.  He  states  that  the  stellate  reticulum 
is  certainly  of  great  imjxirtance  in  the  building  up  of  enamel,  and, 
owing  to  its  richness  in  albumin  and  the  gelatinous  mass  in  its  meshes, 
is,  figuratively  speaking,  a  pantry  from  which  the  enamel  membrane  (the 
ameloblasts)  derives  the  material  for  its  growth, — being  some  distance 
from  blood-vessels. 

The    cells  of  the  stellate  reticulum  are  characterized  by  the  great 
length    of  their   communicating   processes.     Dr.  Sudduth  thinks   that 

Fig.  46. 


.V 


Section  of  jaw,  embryo  of  sheep,  showiug  development  of  dentin  germ :  1,  layer  (portion  of)  of 
ameloblasts ;  2,  external  epithelium  of  enamel  organ  (most  of  the  stellate  reticulum  has  been 
washed  out) ;  3,  enamel  organ  of  permanent  tooth ;  4,  dentin  germ ;  5,  whorls  of  epithelial 
cells  caused  by  breaking  up  of  neck  or  cord  of  enamel  organ ;  6,  part  of  stellate  reticulum. 

this  appearance  is  largely  due  to  shrinkage.  He  says  :  "  I  fully  believe 
that  if  we  could  examine  these  cells  at  once  before  any  shrinkage  occurs, 
we  should  be  able  to  prove  the  fact  that  in  life  they  are  not  stellate  but 

5 


66 


EMBRYOLOGY  OF  THE  DENTAL  TISSUES. 


large  polygonal  cells."  Dr.  Williams  lias  shown  '  that  this  siii)j)()si- 
tion  of  Dr.  Su(l(hith  is  a  fact.  In  his  photo-niicrograpiis  he  has 
clearly  demonstrated  the  cell  contents  tilling  in  the  sj)aces  between 
the  stellate  tissue.  He  shows  them  to  be  very  perfect  nucleated  cells 
lying  in  the  so-called  stellate  reticulum,  which  is  reallv  the  sliuhtlv 
modified  cell  wall. 

The  "  stellate  reticulum/'  then,  may  be  regarded  as  a  storehouse  of 

Fig.  47. 


Section  of  jaw,  cinliryo  of  iiiir,  showing  developing  tooth  (section  teased  away  from  tooth  to  show 
the  fold  in  the  enamel  substance):  1,  enamel  organ;  2,  enamel  substance  not  yet  calcified; 
3,  layer  of  formed  dentin  ;  4,  a  fold  in  the  enamel  substance  ;  5,  dentin  pulp;  6,  folds  at  base 
of  dentin  germ;  7,  developing  bone. 

the  calcium  salts  from  which  the  first-formed  layers  of  enamel  are  sup- 
plied. That  calcium  salts  exist  in  the  meshes  of  the  stellate  reticulum 
may  be  proven  by  placing  a  drop  of  dilute  nitric  acid  on  the  slide  when 
it  passes  under  the  cover-glass.  The  globules  or  granules  which  were 
noticed  there  disappear  as  the  acid  reaches  them,  and  bubbles  accumu- 
late and  are  forced  out  from  under  the  class  cover.  After  the  calcify- 
,ing  process  commences  and  enamel  is  forming,  the  calcium  salts  are 
supplied  by  a  rich  plexus  of  blood-vessels  now  in  direct  contact 
with  the  cells  of  the  stratum  intermedium,  all  other  portions  of  the 
enamel  organ  having  disappeared  from  this  part.  Indeed,  it  is  difficult 
to  demonstrate  clearly  the  cells  of  the  stratum  intermedium  after  any 
'  Dental  Cosmos,  l^ebruary,  1S96. 


THE  ENAMEL   ORGAN. 


67 


considerable  portion  of  the  enamel  has  been  formed ;  they  appear  to 

have  been  lost  in  the  connective  tissne  which  is  evervwhere  above  them. 

The  origin  of  the  enaind  organs  of  tlie  permanent  teeth  may  be  de- 


Frc.  4S. 


v\^jMwaji) 


"    ,.J 


Section  of  incisor  of  rat  (  ■'  175):  a,  blood-vessels  with  eorpuseles  in  situ;  h,  Ijraiieh  of  same  de- 
scending to  supply  capillary  loops  about  secreting  papilla;  c,  ameloblasts.  (Dr.  J.  LeoQ 
Williams*  specimen.) 

scribed  in  general  as  follows  :  From  the  neck  of  the  enamel  organs  of 
the  twenty  deciduous  teeth,  midway  between  the  stratum  Malpighii  and 
the  temporary  enamel  organ,  growths  in  the  form  of  buds  are  being 

Fig.  49. 


Section  of  incisor  of  rat  (X  80):  a,  capillary  loops  torn  out  of  secreting  papillae;  b,  .secreting 
papillpe  after  removal  of  capillary  loops;  c,  ameloblasts;  d,  enamel;  e,  dentin.  (Dr.  J.  Leou 
Williams"  specimen.) 

formed,  increasing  in  length,  and  these  result  in  the  formation  of  the 
enamel  organs  of  the  ])ermanent  teeth,  their  grow^th  taking  place  on 
the  lingual  surface  of  the  temporary  teeth.     Soon  after  this,  tlie  tern- 


68  EMBRYOLOGY  OF  THE  DENTAL   TISSUES. 

Ficj.  50. 


f?"*^'! 


^^' 


Section  of  jaw,  embryo  of  rabbit;  penn.i  n  developing  under  the  temporary  molar: 

1,  enamel  of  temporary  tooth  ;  2,  dental  pulji ;  Z,  developing  alveolar  wall ;  4,  permanent  den- 
tin germ.    (Section  by  Dr.  Sudduth.) 


Fig.  51. 


'*h 


gEii;4f-= 


Section  of  developing  tooth  of  human  embryo  (  •  lOOii)  :  a,  large  nucleated  cells  of  middle  layer 
(reticulum)  of  enamel  organ  ;  h,  stratum  intermedium  ;  c,  ameloblasts.  (Dr.  J.  Leon  Williams' 
specimen.) 


THE  ENAMEL    ORGAN. 


69 


porary  enamel  organ  becomes  separated  from  its  cord.  Between  the 
temporary  enamel  organ  and  the  permanent  enamel  bud,  the  cord 
of  the  temporary  enamel  organ  is  seen  to  be  breaking  up  and  losing 
its  connection  with  the  stratum  Malpighii ;  while  the  cord  for  the  per- 

FiG.  52. 


.4^;..  -V^**^^ 


Section  of  developing  tooth,  embryo  of  calf  i,x  liJ^W) :  a,b,  nuclei  of  reticulum  of  enamel  organ, 
showing  spongiose  character ;  c,  outer  ameloblastic  membrane  ;  d,  inner  ameloblastic  mem- 
brane; e,/,  enamel  globules  faintly  showing  nuclear  network.  (Dr.  J.  Leon  Williams'  speci- 
men.) 

manent  tooth  appears  as  a  continuation  of  the  Malpigliian  end.  The 
cord  for  the  permanent  incisor  in  the  human  embryo  is  formed  about  the 
lifth  month,  and  while  descending  into  the  embryonic  connective  tissue 
assumes  a  spiral  form  of  growth,  as  do  the  necks  of  most  of  the  enamel 
organs  of  the  permanent  teeth,  growing  down  to  take  their  positions 
under  the  tem]iorary  teeth,  where  they  go  through  all  the  changes  that 


70  EMBRYOLOGY  OF  THE  DENTAL    TISSUES. 

have  bc't'ii  spoken  of  in  describing'  the  growth  oi"  tiie  temporary  enamel 
organ.  Dr.  8udduth  says  that  as  a  rnh;  the  cords  ibr  the  permanent 
molars  arise  directly  from  the  epithelium  of  the  mouth,  that  is,  the 
Malpighian  layer.  Other  authorities  state  that  the  first  permanent  molar 
only  is  from  the  Malpighian  layer,  as  is  the  enamel  organ  of  the  tem- 
porary tooth.  Bodecker  is  the  author  of  the  statement  that  all  the 
permanent  molar  teeth  are  an  offspring  of  the  enamel  organs  of  the 
second  temporary  molar  tooth.  The  enamel  organ  of  the  second  per- 
manent molar  is  an  outgrowth  from  the  first  permanent  molar  ;  the 
enamel  organ  of  the  third  permanent  molar  being  an  outgrowth  from 
that  of  the  second.  Von  Brunn  holds  that  the  primary  function  of 
the  enamel  organ  is  that  of  determining  the  form  of  the  future  tooth. 
He  goes  so  far  as  to  assert  that  its  calcification  into  enamel  in  some 
animals  is  a  secondary  function  taken  on  later.  In  support  of  this 
o])inion,  he  says  that  enamel  organs  are  universal,  even  where  no 
enamel  is  found.  He  holds  that  wherever  dentin  is  to  be  found,  there 
is  an  antecedent  "  form-building"  investment  of  enamel  organ. 

The  Dentinal  Papilla. 

The  dentinal  papilla,  or,  preferably,  the  dentin  germ,  has  its 
origin  in  the  embryonic  connective  tissue  of  the  jaw.  Sometime  about 
the  second  month  of  foetal  life,  as  the  enamel  organ  of  the  first-forming 
teeth  assumes  its  flask-like  shape,  and  the  cells  within  its  central  portion 
are  seen  to  be  differentiating,  just  under  it  is  noticed  an  area  of  dense 
tissue,  in  shape  somewhat  like  a  crescent.  It  is  distinctly  outlined  by 
its  dense  and  active  cell-multiplication.  This  is  the  first  indication  of 
the  commencing  growth  of  the  dentin  germ.  As  the  enamel  organ 
enlarges,  and  assumes  the  shape  of  a  surrounding  cap,  a  papilla-like 
growth  takes  place  coincidently  with  it.  About  the  ninth  week  it 
assumes  the  pointed  form  of  the  future  incisor.  With  these  changes  the 
outer  layer  of  the  connective-tissue  cells  next  the  enamel  cells  will  be 
found  to  have  changed  their  form,  and  to  have  assumed  a  very  distinct 
columnar  appearance,  forming  a  layer  somewhat  like  the  enamel  cells, 
but  broader.  This  layer  has  been  falsely  called  a  membrane,  "  mem- 
brana  eboris"  or  membrane  of  the  ivory.  It  is  not  a  membrane,  and 
all  recent  authorities  ignore  it  as  such.  If  the  tissue  has  been  carefully 
prepared,  minute  glistening  bodies  are  seen,  under  the  higher  powers 
of  the  microscope,  within  the  substance  of  the  germ.  These  are  calco- 
^pherites,  and  are  seen  everywhere  near  the  odontoblastic  layer  in  the 
dentin  germ,  as  well  as  in  the  enamel  organ,  near  the  enamel  cells. 
They  are  mostly  minute  globules.  Some  are  larger  than  others,  caused 
undoubtedly    by    several    merging   together.     They    indicate    that    the 


THE  DENTAL   FOLLICLE.  71 

process  of  calcification  is  about  to  begin,  and  are  constantly  present 
while  it  is  going  on,  throughout  the  process  of  the  formation  of  the 
tooth. 

Dr.  Suckluth  is  authority  for  the  statement  that  there  is  no  real 
union  between  the  dentin  germ  and  the  enamel  organ.  There  exists 
no  intimate  connection  between  the  two  surfaces  other  than  that  of  per- 
fect adaptation  to  each  other :  vessels  or  nerves  have  never  been  dem- 
onstrated to  pass  from  one  to  the  other.  The  relation  is  analogous  to 
that  sustained  by  the  epithelium  and  dermal  layers  of  the  mucous 
membrane  of  the  oral  cavity,  from  which  they  have  their  origin. 
Bodecker,  on  the  other  hand,  states  that  there  is  a  connection  between 
tlie  two.  He  says  that  when  the  enamel  organ  is  detached  from  the 
papilla — as  it  frequently  is,  in  sections — its  outer  surface  appears  beset 
with  an  extremely  delicate  fringe,  the  true  connection  between  the  pa- 
pilla and  the  enamel  organ. 

The  Dental  Follicle. 

The  walls  of  the  dental  sacculus  have  their  orio;in  in  the  area  of 
tissue  which  is  so  plainly  marked  by  its  increasing  growth,  seen  just 
under  the  enamel  organ  while  in  the  shape  of  a  flask.  At  this  early  stage 
are  seen,  from  the  outer  edges  of  this  area  of  tissue,  encircling  processes 
which,  as  the  dentin  germ  forms,  grow  rapidly  up,  surrounding  the 
enamel  organ  on  all  sides  (see  Fig.  53).  Some  authorities  have  stated 
that  the  dental  sacculus  does  not  wholly  cover  the  enamel  organ,  but 
in  the  collection  of  the  writer  are  specimens  where  its  walls  are  seen 
to  completely  cover  the  dentin  germ,  so  that  it  apparently  is  wholly 
enclosed.  The  bone  of  the  jaw  is  now  forming  rapidly  about  it  (mak- 
ing a  nest,  as  it  were,  in  which  the  sacculus  and  its  contents,  now 
the  dental  foUide,  rest.  The  cells  within  the  tissue  of  this  sac  are 
found  to  ha\'e  separated  by  growth  into  two  layers.  They  have  not 
changed  their  form,  but  remain  connective-tissue  cells.  The  outer 
layer  is  seen  to  be  much  denser  and  very  much  more  vascular  than 
the  inner  one,  and  this  is  to  form  the  dental  periosteum ;  the  inner  one 
is  said  to  form  the  cementum  of  the  root. 

This  diiferentiation  of  a  portion  of  the  dental  sac  into  a  softer  and 
looser  tissue,  but  little  firmer  than  that  of  the  stellate  reticulum  of  the 
enamel  organ,  has  been  thought  by  Magitot  to  be  sufficiently  pronounced 
to  justify  him  in  calling  it  a  distinct  organ, — the  "  cement  organ."  But 
the  existence  of  such  an  organ  is  doubted  by  many  authorities.  Prof. 
Sudduth  is  of  the  opinion  that  the  tissues  of  the  sacculus  do  not  arise 
wholly  from  the  base  of  the  dentin  germ,  but  largely  from  a  conden- 
sation of  the  fibrous  connective  tissue  in  which  the  enamel  organ  lies. 
The  follicular  wall  just  over  the  surface  of  the  enamel  organ  is  often- 


/2  EMBRYOLOGY  OF  THE  DENTAL   TISSUES. 

times  found  in  folds.  These  have  been  called  "  papilliform  eminences," 
and  are  seen  to  be  projecting  into  or  near  the  enamel  cells.  To  this 
appearance    some   authors   attach    considerable    importance,    but   it   is 

Fig.  53. 


Section  of  jaw,  embryo  of  pig,  showing  dental  follicle:  1,  dental  follicle,  consisting  of  enamel 
organ,  dentin  germ  surrounded  by  the  sacculus  within  the  substance  of  the  jaw  ;  2,  jaw-bone  ; 
3,  tongue ;  4,  papillary  layer  of  tongue. 


doubtful  if  it  has  any  significance.  It,  like  the  folds  in  many  other 
embryonic  tissues,  is  to  be  taken  up  by  the  expansion  of  the  part  by 
growth. 

In  regard  to  the  cement  organ,  Tomes  says  :  "  In  those  creatures 
which  have  comentum  upon  tlie  roots  of  the  teeth  only,  no  special  cov- 
ered organ  exists  ;  but  osteoblasts,  which  calcify  into  cementum,  are 
furnished  by  the  tooth  sac." 

The  gubernaculum  is  a  thin  fibrous  cord  of  dense  tissue,  connecting 
the  permanent  tooth  follicle  in  its  bony  shell  with  the  gum  tissue  just 
back  of  the  neck  of  the  corresponding  temporary  teeth.  It  is  a  struct- 
ure of  no  importance. 


CA  L  CIFICA  TION.  73 

Calcification. 

Calcification  is  a  process  by  which  organic  tissues  become  hardened 
by  a  deposition  of  salts  of  calcium  within  their  substance.  In  the  intercel- 
hilar  tissue  and  in  the  substance  of  the  cells  themselves,  these  salts  are 
deposited  by  the  rich  blood  supply  always  near.  They  are  deposited  in 
minute  particles  and  in  such  fine  subdivisions  as  to  make  it  difficult 
to, demonstrate  many  of  them  even  with  the  higher  powers  of  the  mi- 
croscope. The  intercellular  substance,  either  a  protoplasmic  or  gelati- 
nous fluid  or  semifluid,  contains  the  calcium  particles.  In  it  they  change 
their  nature  chemically,  uniting  \vith  the  albuminous  organic  substance 
of  the  part,  and  form  small  globular  bodies  which  have  been  called 
calco-spherites  ;  and  these,  blending  or  coalescing  at  the  point  of  cal- 
cification, form  a  substance  called  calco-globulin.  This  calco-globulin, 
wliich  is  a  lifeless  matter,  has  been  deposited  through  the  cells  into  the 
gelatinous  substance,  where,  by  a  further  hardening  process,  it  becomes 
the  fully  calcified  matrix. 

Mr.  Rainey,  and  later  Prof.  Harting  and  Dr.  Ord,  have  devoted 
much  time  to  the  study  of  this  substance.  Mr.  Rainey  found  that  if 
a  soluble  salt  of  calcium  be  slowly  mixed  Avith  another  solution  capable 
of  precipitating  it,  the  resultant  calcium  salt  will  go  down  as  an  amor- 
phous powder,  and  sometimes  as  minute  crystals.  But  when  the  cal- 
cium salts  are  precipitated  in  gelatin,  the  character  of  the  calcium  salts 
is  materially  altered.  Instead  of  a  powder,  there  were  found  various 
curious,  but  definite,  forms  quite  unlike  the  crystals  or  powder  produced 
without  the  intervention  of  the  organic  substance.  Mr.  Rainey  found 
that  if  calcium  carbonate  be  slowly  formed  in  a  thick  solution  of  albu- 
min, the  resultant  salt  has  changed  in  character ;  it  is  now  in  the  form 
of  globules,  laminated,  like  tiny  onions,  which  coalesce  into  a  laminated 
mass.  In  this  Mr.  Rainey  claims  to  find  the  clue  for  the  explanation 
of  the  development  of  shells,  teeth,  and  bone. 

At  a  more  recent  date.  Prof.  Harting  took  up  this  line  of  investiga- 
tion and  found  that  other  calcium  salts  would  behave  in  a  similar  man- 
ner. The  most  important  addition  to  our  knowledge  made  by  Prof. 
Harting  lay  in  the  very  peculiar  constitution  of  the  "  calco-spherite," 
by  which  name  he  designated  the  minute  globular  forms  seen  and 
described  by  Rainey.  Mr.  Rainey  found  that  albumin  actually  en- 
tered into  the  composition  of  the  globule,  since  it  retained  its  form 
even  after  the  action  of  acids.  Prof.  Harting  has  shown  that  the 
albumin  left  behind  after  treatment  of  a  calco-spherite  with  acid  is 
no  longer  ordinary  albumin ;  it  is  profoundly  modified,  becoming 
exceedingly  resistant  to  the  action  of  acids.  For  this  modified  albu- 
min  he   proposes  the  name  "  calco-globulin."     Microscopic  glistening 


74  EMBRYOLOGY  OF   THE  DENTAL   TISSUES. 

globules  like  those  (lescrihed  above  are  constantly  seen  at  the  edges 
of  tissue  where  enamel,  eenientuni,  dentin,  or  bone  are  to  l)e  formed 
or  are  forming,  liobin  and  Magitot  have  described  isolated  spherules 
of  calcium  salts  as  occiin-ing  abundantly  in  the  young  pulps  of  human 
teeth,  as  well  as  those  of  other  animals,  and  Tomes  suggests  that  per- 
haps all  deposits  of  calcium  salts  commence  in  this  way.  These  micro- 
scopic globular  bodies  are  calco-spherlfes. 

CALCIFICATION    OF    THE    DENTIN. 

Although  the  enamel  organ  is  first  formed,  with  its  layer  of  amelo- 
blasts  all  ready  to  commence  the  process  of  calcification,  it  is  at  the 
ti])  and  within  the  substance  of  the  dentin  germ  where  this  process 
really  begins.  The  papilla  has  assumed  the  form  of  the  point  of  the 
future  tooth  crown  ;  the  cells  everywhere  upon  its  outer  surface — the 

Fig.  54. 


Section  of  growing  tooth  of  calf  at  birth,  showing  the  layer  of  odontoblasts  and  fibril  cells 
attached  to  tlie  forming  dentin. 

odontoblastic  layer — are  found  to  be  actively  at  work  forming  the  first 
cap  of  dentin.  They  are  seen  to  be  imbedded  in  a  transparent  and 
structureless  gelatinous  substance,  in  which  small  globular  masses  are 
already  forming.  The  cells  are  clearly  defined,  being  somewhat  broader 
than  the  ameloblasts  just  above  them,  and  like  them  are  seen  to  be  in  a 
single  layer,  which  has  been  named  the  "  membrana  eboris,"  but  it  is 
not  a  true  membrane  (see  Figs.  55  and  56).  The  cells  are  found  to  vary 
in  form,  according  as  the  formation  of  the  dentin  is  actively  going  on 
or  not.  During  the  period  of  their  greatest  activity  they  are  broad  at 
the  end  directed  toward  the  dentin  cap,  so  as  to  look  almost  abruptly 
truncated,  having  as  many  as  three  or  four,  in  some  instances  as  many 
as  six,  dentinal  processes  proceeding  from  a  single  cell,  Boll  having 
counted  as  many  as  six.  The  cells  are  finely  granular,  and  are,  accord- 
ing to  Waldeyer  and  Boll,  destitute  of  membranes.       The  nucleus  is 


CALCIFICATION. 


75 


oval  and  lies  in  that  part  of  the  cell  farthest  from  the  dentin,  and  is 
sometimes  prolonged  toward  the  dentinal  processes  so  as  to  be  ovoid 
or  almost  pointed.     The  dentinal  process  passes  into  the  canals  of  the 


Fig.  55. 


Fig.  56. 


Section  of  developing  tooth,  embryo  of  pig: 
1,  stellate  reticulum  of  enamel  organ ;  2, 
stratum  intermedium ;  3,  internal  epithe- 
lium of  enamel  organ  (ameloblasts);  4, 
forming  odontoblasts ;  5,  pulp  tissue. 


Section  of  jaw,  embryo  of  pig:  1,  ameloblasts 
showing  Tomes'  processes  :  2,  layer  of  formed 
dentin;  3,  odontoblasts  ;  4,  pulp  tissue.  (Sec- 
tion by  Dr.  Sudduth.) 


dentin,  and  it  frequently  happens  that  the  layer  of  odontoblasts  is 
slightly  separated  from  the  dentin  in  making  a  section,  when  these 
processes,  which  constitute  the  dentinal  fibrils,  may  be  seen  stretching 
across  the  interval  in  great  numbers.  Intermediate  between  the  per- 
manently soft  central  fibrils  and  the  general  calcified  matrix  is  that 
portion  which  immediately  surrounds  the  fibril,  namely,  the  dentinal 
sheath. 

In  1891  Mr.  Mummery  noted,  as  the  dentin  was  forming,  the 
appearance  of  connective-tissue  fibers,  or  bundles  of  fibers,  just  in  ad- 
vance of  the  main  line  of  calcification.  Their  high  refractive  index 
suggested  their  partial  calcification,  the  processes  being  continuous  from 
the  formed  dentin  to  the  general  connective  tissue  of  the  dentin  germ. 
He  found  in  a  young  developing  tooth  a  distinct  reticulum  of  fine  fibers 
passing  between  and  enveloping  the  odontoblasts.  By  careful  focussing, 
he  saw  these  fibers  gathered  into  bundles  and  incorporated  with  the 
matrix  substance  of  the  dentin,  out  of  which  they  seemed  to  spring. 
The  origin  of  these  fibers  seems  to  be  from  connective-tissue  cells,  which 
are  found  everywhere  in  the  formative  pulp  next  the  odontoblastic  layer, 
and  also,  as  he  has  demonstrated,  between  the  odontoblasts  themselves. 
These  fibers  are  the  scaffolding  on  whicli  the  tooth  matrix  is  built  up  ; 
they  are  incorporated  in  the  matrix  of  the  dentin,  and  form  really  the 
basis  of  its  substance. 


76  EMBRYOLOGY  OF  THE  DENTAL  TISSUES. 

The  odontoblasts  are  modified  connective-tissue  cells  that  superin- 
tend the  deposition  of  the  caleific  material  which  is  to  form  the  calcified 
matrix.  The  tliiekeniiiii;  of  the  dentin  is  by  successive  deposits  of  this 
material  in  the  form  of  layers  which  calcify.  I'^ibrils  from  the  odonto- 
blasts remain  within  the  formed  and  forminii;  dentin  as  the  persistent 
organic  contents  of  the  canals.  This  forming  of  the  dentin  is  at  the 
expense  of  the  dentin  germ,  which  is  thus  gradually  reduced  until  it 
becomes,  Avhen  the  tooth  is  fully  formed,  its  pulp.  Thus  it  is  seen  that 
dentin  is  a  secretion  in  the  form  of  calcific  material  coming  from  the 
abundant  blood  supply  in  the  pulp  tissue  near  the  odontoblasts.  The 
material  is  given  out  from  the  cells  in  a  globular  form  (calco-spherites) 
into  a  protoplasmic  fluid,  or  semifluid,  found  everywhere  against  the 
calcifying  dentin.  In  this  substance  is  the  scaffolding  of  fine  con- 
nective-tissue fibers  spoken  of  by  Mr.  Mummery,  of  London.  The 
calco-spherites  meeting  against  the  formed  dentin  coalesce  into  a 
layer  of  calco-globulin,  and  this,  becoming  fully  calcified,  forms  an 
additional  layer  of  dentin,  and  the  process  continues  until  the  tooth 
is  formed. 

By  the  deposition  of  calcium  salts  into  the  protoplasmic  layer  calco- 
globulin  is  formed,  and  by  its  calcification  the  dentin  tissue  becomes  a 
homogeneous  mass,  penetrated  by  many  parallel  canals  filled  with  the 
persistent  dentinal  fibrils.  Beside  these  parallel  canals  with  their 
fibrillar  contents  many  lateral  canals  are  seen  branching  off  from  the 
main  canals  and  anastomosing  with  neighboring  canals. 

Exceptions  may  be  taken  to  many  of  the  statements  of  histologists 
in  this  field  ;  many  or  most  mistakes  are  traceable  to  faulty  methods 
of  technique.  Processes  which  involve  the  securing  of  specimens 
while  they  are  yet  warm  are  greatly  preferable.  These  are  placed  in 
a  quarter  of  one  per  cent,  to  one-half  of  one  per  cent,  solution  of 
chromic  acid,  wdiieh  is  changed  several  times  a  day,  for  three  or  four 
davs.  At  the  end  of  this  time  the  eda;es  of  the  dentin  which  were 
calcified  are  found  to  be  sufficiently  softened  to  make  a  number  of 
sections.  The  teeth  are  then  taken  from  the  acid  solution,  washed  in 
distilled  water,  placed  in  a  solution  of  gum  arabic  for  several  hours,  and 
next  transferred  to  a  solution  of  alcohol  to  abstract  the  water.  Paraffin 
and  lard  are  melted  together  and  poured  into  a  convenient  mould. 
When  this  clouds  in  the  process  of  cooling,  the  tooth,  which  has  had  its 
outer  surface  dried  as  much  as  possible  with  bibulous  paper,  is  placed  in 
it  and  the  whole  allowed  to  cool.  The  microtome  for  this  purpose  should 
permit  the  immersion  of  both  tissue  and  knife  when  the  sections  are 
cut.  These  sections  float  off  in  the  fluid,  and  remain  there  until  used. 
Sections  are  cut  until  the  calcified  tissue  is  reached.  The  sections 
are   placed  in    distilled   water  for   a  few   minutes  to  dissolve  out  the 


CALCIFICATIOX. 


77 


gum,  and  then  mounted  in  glycerin  jelly.  The  difiPereuce  in  the 
appearance  in  the  tissue  prepared  by  this  method  is  marked.  It  is 
seldom  necessary  to  stain  tissues  which  are  to  be  studied  under  the 
higher  powers  of  the  microscope. 

The  dcnti)i  matrix  is    mainly  a    connective-tissue    calcification,  and 
it  should  be  remembered  in  examining  sections  of  forming  dentin  that 

Fig.  57. 


'S 


-^^fcvlllV-il**^-^ 


Plflffi^lli^. 


^r' 


Section  of  growing  tootli  I'l'  <air  at  lii 
and  two  odontoblasts 


th,  shdw  inu  till'  fiiniu'd  ilriitiii,  tlie  layer  of  calco-globulin 
a  fibril  is  seen  at  the  side  of  one  of  them. 


sections  are  seen  at  that  stage  of  growth  at  which  the  death  of  the 
part  left  it.  In  some  the  odontoblasts  are  seen  square  and  abrupt  against 
the  calcified  matrix,  having  no  appearance  of  other  tissue  between  them. 


Fig.  58. 


Section  of  growin;-'  t  i  ith  -i  mW  at  birth,  showing  the  layer  of  odontoblasts  -luar.  aiul  abrui>t 
against  the  forming  dentin ;  some  of  the  fibril  cells,  or  dentin  corpuscles,  that  are  pear- 
shaped,  are  seen  running  between  them. 

In  others  the  odontoblasts  are  seen  square  and  abrupt  against  a  layer 
of  a  fibrous,  gelatinous  tissue,  which  is  seen  to  be  filling  with  globular 


f8 


EMBRYOLOGY  OF  THE  DENTAL   TISSUES. 


masses  (Fig.  57).  This  layrr  is  hctwecn  the  odontoblasts  and  the  cal- 
eifi(>d  in:itrix.  A  section  from  another  embryo  will  show  a  different 
picture.  Here  is  seen  a  layer  of  mostly  ])ear-sha|)('d  cells,  not  (juite 
against  the  calcified  matrix,  showing  their  fibrils  (h-:i\\ii  out  and  I'un- 
ning  into  the  canals  of  the  matrix  (Fig.  58).  Thci-c  is  no  appcarancse 
of  a  gelatinous  layer,  while  here  and  there  against  the  calcified  matrix 
are  what  appear  to  be  used-up  odontoblasts,  only  portions  of  them 
showing.  The  cells  in  this  picture  rarely  show  more  than  one  fibril 
running  into  the  canals  of  the  matrix.  Again,  a  section  from  another 
tooth  will  show  layers  of  calco-globulin  merging  together  and  forming  a 
new  laver  of  the  matrix,  and,  in  this,  parts  of  the  odontoblasts  seem  to 
lose  their  identity  (Figs.  59-61).    ^Vn  irnjxu'tant  fact  not  to  be  lost  sight 

Fig.  59. 


.^V  /  ^'•^• 


^  *     :- 


Section  of  develoiiin.;  ,..  ...  ..i..  ..;   ...it;..  .;..-,.  .......i.  ,-,....,  .,,,u  ,,i,-u..j ,...;,-  layrr  of  dentin 

matrix.    The  caleospherites  are  seen  forming  a  layer  of  calco-globulin  wliich  by  further  calci- 
fication is  to  become  the  matrix. 


of  is  that  all  of  these  appearances  indicate  the  different  stages  in  the 
growth  of  the  dentin  matrix.  Conclusions  cannot  be  drawn  from  any 
one  of  them,  so  all  must  be  studied.  These  appearances  are  not  found 
at  the  early  stages  alone  ;  they  are  also  seen  when  the  matrix  is  nearly 
formed. 

The  odontoblasts  are  masses  of  protoplasm  without  membranes,  and 
are  at  a  certain  stage  of  growth  square  and  abrupt  against  the  matrix 
(Fig.  58).  It  is  an  easy  matter  to  find  among  them,  and  immediately- 
adjacent,  large  numbers  of  pear-shaped  cells,  tapering  into  the  dentinal 
fibril.  The  odontoblasts,  when  calcification  is  active,  are  scarcely 
more  than  masses  of  protoplasm,  filled  with  minute  globules  (Fig.  62). 
The  fibrils  which  appear  to  come  from  them,  described  by  Tomes  as 
pulp,  lateral,  and  dentin  processes,  originate   probably    from  a  fibril- 


CALCIFICATION. 
Fig.  60. 


79 


■>  r 


)-^  ■.. 


Seetiou  of  growing  :     :i^i\\;ii_'  iii  r.    .     .  .  i  <  "iMutoblasts ;  also  the 

lavLT  (il  fak'ij-gliiljuliii  anU  the  lonmiig  dfiiliu. 


Fig.  61. 


Section  of  growiug  louth  of  ualf  at  birth,  showing  fibrils,  fibril  cells,  and  odontoblasts.    The  pulp 
has  been  teased  away,  leaving  these  cells  clinging  to  the  formed  dentin. 

Fig.  62. 


Section  of  growing  tooth  of  calf  at  birth,  showing  odontoblasts  and  fibril  cells. 


80  EMBRYOLOGY  OF  THE  DENTAL   TISSUES. 

forming  cell.  These  pass  through  the  soft  substance  of  the  odonto- 
blasts (protoplasm )  and  seem  to  be  a  part  of  them,  but  in  fresh,  young 
sections  the  so-called  processes  move  in  the  substance  of  the  odonto- 
blasts bv  j>ressure  on  the  cover-glass,  and  the  fibril  may  be  traced  to 
a  i)ear-shaped  cell  beyond  (Fig.  62).  There  will  usually  be  found  as 
manv  })rocesses  going  out  from  sides  or  ends  of  the  odontoblasts  toward 
the  pulp  as  there  are  going  into  the  matrix  from  the  dentin  end  of  the 
cell.  In  cross  sections  of  the  odontoblasts,  delicate  light  spots  are  seen 
in  the  substance,  which  are  probably  the  cut  fibers.  When  the  layer 
of  odontoblasts  is  teased  away  from  the  forming  dentin,  fibrils  are  seen 
bridging  the  gap,  apparently  offshoots  from  the  odontoblasts  ;  but  on 
careful  examination  there  will  usually  be  found  a  decided  line  of  demar- 
cation across  the  fiber  at  the  point  where  it  meets  the  square  end  of  the 

Fig.  63. 


Section  of  growing  tooth  of  calf  at  birth;  odontoblasts  that  were  square  and  abrupt  against  the 
forming  dentin,  showing  the  line  of  demarcation  between  the  cell  and  the  fibril.  They  are 
attached  to  the  pulp. 

odontoblast  (Fig.  63).  This  line  seems  to  show  that  the  fibril  was  not 
continuous  with  the  protojilasm  of  the  cell.  Other  sections  which  have 
been  separated  by  teasing,  show  odontoblasts  having  their  side  masses 
of  protoplasm  drawn  away  from  the  fibril  which  apparently  has  run 
through  it.  Some  of  this  protoplasm  is  left  upon  the  fibril,  giving  it 
a  ragged  appearance  as  it  passes  from  a  canal  in  the  matrix  across  to 
the  separated  pulp  tissue,  bridging  the  gap. 

The  pear-shaped  cell  has  perhaps  a  more  important  function  than 
the  odontoblast  proper.  It  is  to  supply  the  life  and  nourishment  to 
the  whole  of  the  calcified  matrix,  as  the  bone  corpuscle  within  its 
lacuna  supplies  life  and  nourishment  to  bone  and  cementum. 

Minute  calcium  globules  or  calco-spherites  are  seen  to  be  arranging 
themselves  against  the  already  formed  matrix,  where  they  collect  in  large 


CALCIFICATION. 

Fig.  64. 


81 


Section  of  human  tooth,  showing  globules  of  calco-globulin  which  have  been  deposited  in  the 
gelatinous  layer  by  the  odontoblasts ;  these  have  been  pulled  away  in  making  the  section. 
(Section  by  Mr.  Mummery.) 


Fig.  65. 


Fig.  66. 


Av 


vA 


Fig.  67. 


Sections  of  growing  tooth  of  calf  at  birth,  showing  forinution  of  layer  of  masses  of  calco-globulin 

to  form  layer  of  dentin. 


82  EMBRYOLOGY  OF  THE  DENTAL   TISSUES. 

numbers,  and  lose  their  individuality  by  merging  into  one  another,  form- 
inf  hirger  globules,  of  various  shapes  and  sizes  (Fig.  64),  seeming  to 
take  into  their  substance  portions  of  the  odontoblast.  These  globules 
enlarge  until  they  reach  their  typal  width,  expand  laterally,  meeting 
and  coalescing  with  others.  The  minute  glol)ules  are  seen  within  the 
odontoblasts  of  different  sizes,  all  having  a  glistening  appearance,  some- 
thing like  fat  globules  in  cells.  The  early  layers  formed  by  the  glol)- 
ules  are  about  the  width  of  the  band  of  formative  cells.  (See  Figs. 
65,  66,  67). 

CALCIFICATION    OF    THE    ENAMEL, 

The  statement  made  by  Tomes  and  others  that  enamel  is  formed 
by  the  actual  conversion  of  the  enamel  cells  into  the  enamel  rods  is  an 
erroneous  one.  The  enamel  cell  does  not  calcify ;  it  superintends  the 
laying  down  of  calcific  material  which  is  to  form  the  rod.  For  the 
earliest  deposit  of  enamel  the  calcium  salts  are  stored  in  the  meshes 
of  the  so-called  stellate  reticulum,  and  as  the  first  enamel  forms,  the 
enamel  organ  proper  disapjjears  at  this  point.  Only  the  two  inner- 
most layers  remain  ;  these  are  the  layer  of  the  columnar  cells  (amelo- 
blasts)  over  the  forming  enamel,  and  a  layer  of  cells  somewhat  resem- 
bling connective-tissue  cells  (the  stratum  intermedium)  over  these.    The 

two   layers   are   separated   by  Avhat 
^^^-  ^^'  appears  to  be  a  line  of  tissue  which 

has  been  called  a  membrane.     The 
embryonic  connective  tissue   of  the 
jaw  is  now  in  direct  communication 
with  the  stratum   intermedium,  and 
_     a    rich    blood    supply  is    developing 
near   the    point   of  juncture.       The 
function  of  the  cells  of  the  stratum 
intermedium  is    supposed  to   be  the 
'^      supplying  of  new  cells  to  the  amelo- 
blastic layer  as  they  may  be  needed  by 
the  increase  in  the  circumference  of 
Section  of  i.u, n.u,  .1,  f  Jw.ing  tooth,  showing     the  enamel,  as  new  enamel  is  formed  ; 
calcification  of  enamel :  1,  globules  of  cai-     ^^  furnish  the  Organic  fluid  in  M-hich 

co-globulin    deposited    on    dentin    cusps  ^  i  •      i 

from    the    enamel    cells;    2,  dentin    (the  the      calcium      Salts     are      deposited; 

enamel  cells  have  been  cutaway  in  prepar-  ^^^j    ^^    supplv    the    fine    network    of 
ing  the  section).  i  i    .  i  .   i 

fibers,  the  scaffolding  upon  wdiich 
the  enamel  rods  are  to  be  built.  Prof.  Sudduth  is  the  authority  for 
the  statement  that  enamel  is  nothing  more  or  less  than  a  coat  of  mail 
supplied  by  Nature  to  protect  the  dentin. 

Enamel  cells  that  have  been  properly  prepared  and  not  shrunken 
will  be  seen  filled  with  minute  globules.     The  authorities  who  speak  of 


CALCIFICATION. 


83 


granules  of  calcium  salts  have  described  them  as  seen  in  the  shrunken 
cells  in  the  tissue  as  it  is  usually  prepared.  They  are  really  globular, 
though  minute.  If,  just  as  calcitication  commences,  a  few  drops  of 
dilute  nitric  acid  be  placed  on  tlie  slide  near  the  edge  of  the  cover- 
glass,  the  liquid  will,  by  capillary  attraction,  run  under,  and  these  re- 
fractive granular  bodies  in  the  stellate  reticulum  will  disappear,  as  will 


Fig.  69. 


Fk;.  to. 


mi 


Sections  from  growing  tooth  of  calf  at  birth,  showing  how  enamel  rods  are  formed  from  the  globu- 
lar masses  of  calco-globulin. 


Fk;.  71. 


those  that  are  in  the  enamel  cells  themselves.  Large  numbers  of  small 
bubbles  will  accumulate,  and  force  themselves  out  from  under  the  cover- 
glass.  This  would  seem  a  positive  demonstration  of  the  presence,  in  the 
stellate  reticulum  and  enamel  cells,  of  calcium  carbonate  just  previous 
to  commencing  calcification.  In  teasing  off  portions  of  active  enamel 
cells,  we  find  the  surface  of  the  dentin  on  which  it  is  being  formed 
covered  with  layers  of  globules  that  have  been  deposited  there  by  the 


84  EMIUIYOLOGY  OF  THE  DENTAL    TISSUES. 

eiiamol  cells  (Fij;.  68).     These,  given    (nit   from  tli(>  cell    continually, 

form  the  cnaniel  rods.     One  rod  is  separated  tVoni  anotlici'  hy  a   |n-oto- 

j)lasnuc  cenieut  substance. 

Dr.  Graf  Spee  says  that  whcii   the  tissue  is  j)roj)erly  ])repared — and 

he  lays  great  stress  on  this  point — at  the  time  of  the  formation  of  the 

enamel,  the  globules  are  always  to  be  found.     Their  entire  absence  at 

„      „„  earlier   stap-es   is    an    indication    that 

Fig.  72.  ^ 

these  globules  are  an  enamel  sub- 
stance. He  gives  to  them  the  name 
'*  enamel  drops,"  and  says  he  saw 
these  "  enamel  drops,"  when  enamel 
is  to  be  formed,  appear  only  in  the 
half  of  the  enamel  cells  wdiich  rests 
[J  on  tiic  dentin;  afterward  they  were 
to  be  seen  farther  up  in  the  cell,  but 
not  quite  to  the  region  of  its  nucleus. 
Many  of  them  were  so  small  as  to  be 
scarcely  measurable,  and  they  are  al- 
ways spherical.  Great  numbers  of 
Section  of  (leveinpiM    t    .1,  of  calf  at  birth,    ^\^^,^  ^^^  collected  at  the  periphery, 

showinj;  tirst-foriiiiii;;  layer  i)f  enamel.    The  ,  l        i  j  7 

globules  of  caico-giobuiin  are  seen  arranged    and  appear  here  either  to  be  completely 

in  lines  where  rods  are  to  be  formed:  1  ^^y^^^^     ^.^  to     fuse     together.        The 

enamel  cells  containing  caleo-spherites ;  ■:!,              ^  b 

globules  arranged  to  form  rods;  3,  first-  loWCr    part  of    the    cell     COntainS     the 

forming  layer  of  enamel :  4,  dentin.  1                ,,  ^    ^             )5       1  •    1 

larger  "  enamel  drops,  which  merge 
without  sharp  boundaries  into  the  substance  of  the  enamel  rods.  This 
then  appears  as  a  part  of  the  enamel  cell,  in  which  the  originally  iso- 
lated "enamel  drops"  have  run  together  into  a  continuous  mass,  and 
the  growth  of  the  enamel  rod,  once  begun,  appears  to  take  place  by  the 
addition  of  new  "  enamel  drops." 

The  minute  globular  forms  described  by  Dr.  Sj^ee  are  calco-s])herites  ; 
the  larger  ones,  his  "  enamel  drops,"  are  globules  of  calco-globulin  which 
are  to  form  the  rods  (Fig.  72). 

Appearances  of  calcified  fibers  ])roj('cting  beyond  the  line  of  calci- 
fication are  seen  when  studying  sections  of  forming  young  enamel,  and 
these  are  evidences  that  fine  processes  of  fibers  from  the  cells  of  the 
stratum  intermedium  pass  down  through  and  among  the  ameloblasts  to 
the  forming  enamel  beneath.  These  are  probably  the  processes  which 
i\rr.  Tomes  saw  and  descrilied  as  connecting  the  enamel  cells  with  the 
stratum  intermedium.  If  one  separates  slightly  the  enamel  cells  from 
the  stratum  intermedium  the  j^arted  cells  will  have  the  appearance  of 
broken  processes  or  fibers,  and  we  may  be  able  to  see  fibers  crossing 
from  the  enamel  cells  to  the  stratum  intermedium. 

A  longitudinal   section  of  a  human   tooth   at  birth,  just   after  the 


CALCIFICATION.  85 

process  of  calcification  in  the  enamel  has  begun,  will  show,  between 
the  enamel  cells  and  the  formed  enamel,  a  thin  layer  which  has  been 
called,  by  earlier  investigators,  the  membrana  prceformativa.  It  was 
misunderstood  then  :  it  is  not  a  membrane.  It  is  the  latest  deposition 
of  enamel  from  the  enamel  cells,  composed  of  globules  or  masses  of 
calco-globulin ;  and  around  these  globules  there  seems  to  be  a  fibrous 
network.  Connecting  with  this  fibrous  network,  and  running  to  the 
formed  enamel  beneath,  are  innumerable  thread-like  processes,  in  ap- 
pearance like  fibers.  There  are  indications  of  fibers  which  have  been 
broken  on  the  upper  portion  of  thi^  thin  layer ;  these  appear  as 
though  they  had  been  broken  otf  in  the  separation  of  the  layer  from 
the  enamel  cells.  In  a  longitudinal  section  of  the  tooth  of  a  calf  at 
birth,  when  the  recently  formed  layer  of  enamel  is  still  in  contact  with 
the  fully  calcified  enamel,  this  younger  portion  may  be  teased  oif, 
exposing  to  view  what  appear  to  be  fibrils  standing  out  from  the  sur- 
face. These  have  apparently  been  drawn  out  from  the  only  partially 
calcified  new  tissue.  In  other  sections  this  appearance  is  more  marked. 
Thty  may  appear  so  large  that  it  is  probable  they  have  been  enlarged 
either  by  the  action  of  reagents  or  by  calcific  matter  clinging  to  a 
fiber,  if  one  is  there,  and  tliey  are  undoubtedly  partially  calcified. 
They  are  very  much  coarser  than  the  fine  fibrils  seen  between  the 
enamel  cells.  Deeper  within,  these  processes  are  seen  to  surround  the 
globules  or  masses  which  have  been  deposited  by  the  enamel  cells,  and 
which  are  forming  the  rods.  In  other  sections  from  the  tooth  of  the  calf 
the  younger  layer  of  forming  enamel  shows  a  network  of  fibers ;  they 
are  surrounding  the  recent  deposition  of  globules.  It  is  only  in  this 
layer  that  this  appearance  is  clearly  shown  ;  this  network  in  more 
fully  formed  enamel  cannot  be  seen,  yet  a  distinct  network  is  always 
visible  in  the  layer  first  deposited.  It  is  probable  that  these  pro- 
cesses have  their  origin  among  the  cells  of  the  stratum  intermedium  ; 
that  they  pass  either  within  or  between  the  enamel  cells,  and  thus  on, 
to  form  a  very  fine  fibrous  substructure,  throughout  which  are  deposited 
the  globules  which  are  to  form  the  future  enamel  rods.  When  the  cal- 
cification of  the  rod  is  complete,  the  calcium  salts  have  been  so  densely 
deposited  as  to  entirely  obscure  the  appearance  of  any  fiber. 

To  sum  u]) :  there  probably  exists  in  developing  enamel,  as  has 
already  been  found  in  developing  bone  and  dentin,  a  fibrous  sub- 
structure on  and  throughout  which  the  enamel  globules  are  deposited. 
After  the  enamel  is  wholly  formed,  this  structure  seems  to  be  wholly 
blotted  out  in  the  dense  calcification  of  the  tissue  (Figs.  73,  74).  In 
sections  of  completely  formed  enamel  the  writer  has  been  unable  to 
trace  it,  although  the  methods  of  those  who  claim  to  have  seen  it 
have  been  faithfully  followed.     In  regard  to  a  protoplasmic  reticulum 


86  EMBRYOLOGY  OF   THE  DENTAL    TISSUES. 

Fui.  73.  Fig.  74. 


Sections  of  very  young-  enamel  (human),  showing  the  appearance  of  a  fibrous  s-tructure  :  1,  enamel 
cells;  2,  newly  forming  enamel;  3,  dentin. 

of  living  matter  in  formed  enamel,  it  is  undemonstrable.  Klein  states 
that  it  is  improbable  that  nucleated  protoplasmic  masses  are  contained 
in  the  interstitial  substance  of  the  enamel  of  a  fully  formed  tooth. 


CALCIFICATION    OF    THE    CEMEXTUM. 

In  the  year  1858,  Magitot,  a  French  histologist,  claimed  to  have 
found  within  the  follicle  of  a  developing  tooth  a  special  organ  for  the 
development  of  the  cementum.  In  18G1  Robin  and  INIagitot  made  a 
presentation  of  the  same  facts.  With  the  exception  of  these  authors, 
no  other  authority  has  recognized  the  presence  of  this  special  organ  ; 
while  Kolliker,  Waldeyer,  Herz,  and  others  had  formerly  denied  its 
existence.  Although  there  are  appearances,  in  a  fully  formed  follicle, 
of  a  tissue  between  the  calcifying  dentin  germ  and  the  outer  covering 
of  the  sacculus,  which  might  admit  of  the  supposition  of  the  existence 
of  such  an  organ,  it  cannot  be  traced  with  certainty.  The  appearance 
may  be  noted  in  sections  from  embryos  of  the  pig  and  calf.  At  a  later 
stage  when  the  crown  is  further  developed  there  are  also  to  be  seen 
infoldings  of  the  tissue  at  the  base  of  the  germ  which  may  develop 
into  a  special  organ  for  the  formation  of  the  cementum,  as  stated  by 
Magitot ;  but  in  teeth  more  matured,  where  the  cementum  has  already 
commenced  its  growth,  there  are  no  indications  of  a  special  organ. 

If  the  developing  tooth  is  examined  just  after  the  cementum  has 
begun  to  form,  its  matrix  will  be  found  to  be  made  up  of  masses 
looking  like  scales  of  a  tissue  found  everywhere  on  the  borderland  of 
calcification.  It  is  calco-globulin,  and  has  been  formed  from  globules. 
At  this  early  stage  the  calcific  material  is  in  the  osteoblasts,  and  is 
given  from  them  to  the  dentin,  where  a  thin  layer  is  forming.     The 


THE  DENTAL  PULP.  87 

osteoblasts  are  filled  with  minute,  glistening  globules.  As  the  growth 
continues,  these  cells  appear  to  fuse  into  the  cementum  already  formed. 
At  the  neck  of  the  tooth  outside  this  layer,  which  is  forming  the  matrix 
of  the  cementum,  a  row  of  cells  is  seen  which,  according  to  Rollet,  re- 
sembles an  epithelium.  They  are  really  new  osteoblasts  or  cemento- 
blasts  filled  with  the  minute  glistening  bodies.  Just  exterior  to  these 
cells,  roundish  nucleated  cells  with  innumerable  processes  are  seen 
slightly  resembling  a  stellate  reticulum.  Outside  of  these  is  a  con- 
nective-tissue layer  which  will  become  the  periosteum.  This  slight 
amount  of  stellate  tissue  is  probably  what  has  been  called  the  special 
cement  organ.  Across  the  developing  matrix  of  the  cement  are  found 
numerous  connective-tissue  fibers  seen  and  described  by  Sharpey  and 
named  after  him  Sharpey's  fibers.  They  become  calcified  within  the 
matrix.  As  the  cementum  grows  thicker  we  find  infolded  within  its 
substance  nucleated  bodies  which  appear  to  be  connective-tissue  cells. 
They  apjiear  larger  than  the  osteoblasts  and  are  forming  the  regular 
lacuuffi  of  the  cementum.  Their  function  is  to  give  nourishment  to 
the  matrix  of  the  cementum,  anastomosing  with  one  another  by  means 
of  many  fine  canals,  many  of  which  run  in  the  direction  of  the  termi- 
nation of  the  dentinal  canals  as  though  connecting  with  them.  They 
are  not  as  regular  as  those  in  true  bone,  and  are  often  very  much  larger. 
The  processes  of  these  cells  anastomose  with  the  dentinal  canals  through 
the  interglobular  spaces  of  the  so-called  granular  layer  of  Tomes.  Thus 
the  matrix  of  the  cementum  is  formed  from  the  cementoblasts  which 
have  become  filled  with  calcific  material  from  the  blood  supply  every- 
where near.  They  rest  against  already  formed  dentin  and  become 
merged  into  a  layer  of  calco-globulin,  which  in  turn  becomes  calcified 
into  the  first  layer  of  cementum.  Layer  after  layer  is  formed,  and 
this  gives  to  the  cement  the  peculiar  laminated  appearance  so  often 
seen  in  it. 

The  Dental  Pulp. 

The  tooth  pulp  is  that  which  remains  of  the  dentin  germ  after  cal- 
cification is  completed.  It  is  very  generally  but  erroneously  called  the 
"  nerve."  In  the  young  tooth  it  is  composed  of  connective-tissue  matrix 
which  contains  the  nerves  and  vessels  supplying  the  dentin.  These 
are  more  numerous  near  the  odontoblastic  layer,  the  nerve  fibers  appear- 
ing to  terminate  here.  The  odontoblasts  cover  the  surface  of  -pulp  like 
an  epithelium.  Just  Avithin  these  is  a  layer  of  cells  consisting  of  a 
comparatively  pale  and  transparent  zone,  and  this  has  been  called  the 
basal  layer  of  Weil.  It  is  described  as  consisting  of  fine  connective- 
tissue  fibrils  which  communicate  with  the  processes  of  the  odontoblasts. 
Von  Ebner  doubts  the  existence  of  this  layer,  as  does  Rose. 


88 


EMBRYOLOdY   OF  THE  DENTAL    TISSUES. 


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CHRONOLOGY  OF  TOOTH  DEVELOPMEXT. 


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90  EMBRYOLOGY   OF   THE  DENTAL    TISSUES. 

In  a  recent  ]);i|){'r  on  tlie  Histology  of  the  Pulp,  by  Erwin  Hoelil,  he 
states  that  the  cells  of  the  pulp  show  in  the  diU'erent  life  periods  cha- 
racteristic differences  in  form  and  number.  Three  kinds  are  found, 
Avhieh  arise  from  one  another  by  metamorphosis  in  the  following  way  : 
(1)  Round  cells  with  large  nucleus  and  scanty  ])rot(ii)lasm.  (2)  Irregu- 
larly shaj)ed  cells  with  many  freely  anastouiosing  ])roccsses.  (.'i)  Spindle- 
sha])c(l  cells  with  the  same  character  as  the  ibregoing.  The  (changes  of 
the  cell  form  begin  at  the  })eriphery  and  ])roceed  towai'd  the  centre  of 
the  ])ulp.  The  outermost  ])eri])heral  layer  of  the  branched  cells  contains 
the  elementary  or  primary  odontoblasts.  Ccntralward  from  these  is  a  cell 
layer  which,  with  reference  to  the  function  of  its  elements,  is  called  the 
conjugation  cell  layer.  The  secondary  odontoblasts  arise  by  conjugation 
of  the  primary  odontoblasts  with  the  conjugation  cells,  and  they  form 
the  dentin.  The  conjugation  processes  probably  cease  only  with  the 
com])letion  of  growth  in  the  tooth. 

Of  the  peripheral  processes  of  the  primary  odontoblasts  the  larger 
one  represents  what  will  be  the  future  dentin  fibril.  The  increase  of 
cells  seems  to  be  dependent  upon  the  development  of  the  capillaries, 
inasmuch  as  more  cells  are  found  where  the  distribution  of  capillaries  is 
most  dense,  i.  e.  on  the  periphery  of  the  pulp.  Tlie  gradual  decrease 
of  the  number  of  branch  cells  in  the  centre  of  the  pulp  during  the 
course  of  development  is  because  only  trunk  vessels  are  found  here. 
In  the  place  of  these  destroyed  cells  we  find  a  delicate  cellular  network 
which  is  probably  derived  from  the  numerous  anastomoses  of  the  cell 
processes.  Next  to  or  just  within  the  odontoblastic  layer  is  seen  a  bright 
zone  variable  in  width  ;  this  is  the  so-called  Weil's  layer.  Between  this 
and  the  fibrous  or  central  portion  of  the  pulp  is  an  intermediate  layer 
which  forms  a  contrast  with  the  delicate  fibrous  elements  of  Weil's  layer, 
and  in  this  way  Weil's  layer  is  made  visible. 

The  ground  substance  of  the  pulp  by  a  certain  method  of  treatment 
shows  a  dense  interlacing  of  fibrillse  wdiieh  are  arranged  parallel  to  one 
another  and  seem  to  run  in  the  direction  of  the  axis  of  the  tooth. 

The  Gum. 

Gum  tissue  is  the  same  as  that  of  the  general  mucous  membrane  of 
the  mouth.  It  is  more  dense  because  it  is  bound  down  to  the  bone 
by  numerous  fibers  of  its  own,  and  it  is  also  united  with  the  periosteal 
tissue  which  spreads  into  it  in  every  direction.  Numerous  large  single 
and  compound  papillffi  are  seen.  The  blood  supply  is  abundant,  but 
nerve  tissue  is  not  often  found.  The  histological  appearances  which 
look  like  young  enamel  organs  are  the  glands  of  Serres.  Near  develop- 
ing teeth  epithelial  clusters  are  frequently  seen,  the  remains  of  the  dis- 
appearing necks  of  the  enamel  organs.     The  cells  of  the  stratum  Mai- 


THE  PERICEMESTUM  OR  ALVEOLO-DENTAL  MEMBRANE.       91 

pighii  of  the  epithelium  are  seen  to  be  in  columns,  and  from  these 
new  cells  are  formed,  which  flatten  and  lose  their  vitality  as  they 
near  the  outer  surface,  wdiere  they  are  given  off  as  lifeless  scales. 

The  Pericementum  or  Alveolo-dental  Membrane. 

This  is  a  formation  of  fibrous  connective  tissue,  having  its  origin 
from  the  outer  layer  of  the  sacculus  (Fig.  75).  It  differs  from  the  gum 
tissue  in  that  it  is  not  so  dense.  Tomes  speak  of  it  as  having  a  rich 
supply  of  nerve  fibers. 

Fig.  75. 


Alveolar  dental  mcmbrune  (section  from  ja,\   d  kiitfiu  :  1,  alveolar  dental  membrane  ;  2,  bone 

of  alveolus;  3,  dentin. 

The  pericementum  passes  into  the  gum  at  the  tooth  neck,  w'here  it  is 
thicker  than  at  any  other  part.  It  is  seen  to  be  everywhere  connected 
with  the  periosteal  membrane  of  the  alveolar  process.  The  general 
direction  of  its  fibers  is  across,  slightly  wavy,  downward  from  the 
alveolus  to  the  tooth  root.  In  the  young  tooth  there  are  no  breaks  in 
the  continuity.  There  is  no  appearance  of  two  separate  membranes, 
one  for  the  root  and  the  other  for  the  alveolus;  but  simply  a  mem- 
brane common  to  both  surfaces. 


92  EMBRYOLOGY  OF  THE  DENTAL   TL'^SUES. 

The  pcriec'tiicntuni  loniis  an  clastic  membrane  and  acts  as  a  cushion 
to  lessen  the  concussion  when  the  teeth  come  to<i;ether  during  mastica- 
tion. Its  connective-tissue  fibers  are  seen  to  pass  into  the  cementum, 
and  within  that  substance  are  supposed  to  be  Sharpey's  fibers.  Where 
the  cementum  is  thicker  it  is  rich  in  cellular  structure.  The  pericemen- 
tum, then,  connects  with  the  cementum  by  its  fibers;  these  in  turn  con- 
nect with  the  branches  of  the  cement  corpuscles,  through  these  with  the 
granular  layer  of  Tomes,  and  thence  on  to  the  fibrils  of  the  dentin. 

Nasmyth's  Membrane. 

Concerning  this  structure  Tomes  states  that — 

"  lender  the  name  of  Nasmyth's  membrane,  enamel  cuticle,  or  per- 
sistent dental  capsule,  a  structure  is  described  about  which  much  differ- 
ence of  opinion  has  been,  and  indeed  still  is,  expressed.  Over  the 
enamel  of  the  crown  of  human  or  other  mammalian  teeth,  the  crown  of 
which  is  not  coated  by  a  thick  layer  of  cementum,  there  is  an  exceed- 
ingly thin  membrane,  the  existence  of  which  can  only  be  demonstrated 
by  the  use  of  acids,  which  causes  it  to  become  detached  from  the  surface 
of  the  enamel.  When  thus  isolated  it  is  found  to  form  a  continuous 
transparent  sheet,  upon  which,  by  staining  with  nitrate  of  silver,  a 
reticulated  pattern  may  be  brought  out,  as  though  it  were  made  up  of 
epithelial  cells.  The  inner  surface  of  Nasmyth's  membrane  is,  however, 
pitted  for  the  reception  of  the  ends  of  the  enamel  prisms,  which  may 
have  something  to  do  with  this  reticulate  ajDpearance.  It  is  exceedingly 
thin,  Kolliker  attributing  to  it  a  thickness  of  only  one  twenty-thousandth 
of  an  inch.  But,  nevertheless,  it  is  very  indestructible,  resisting  the 
action  of  strong  nitric  or  hydrochloric  acid,  and  only  swelling  slightly 
when  boiled  in  caustic  potash.  Notwithstanding,  however,  that  it  resists 
the  action  of  chemicals,  it  is  not  so  hard  as  the  enamel,  and  becomes 
worn  ofiF  tolerably  speedily,  so  that,  to  see  it  well,  a  young  and  unworn 
tooth  should  be  selected." 

The  writer's  investigations  lead  to  the  inference  that  the  membrane 
is  nothing  more  than  the  layer  of  cells  of  the  internal  epithelium  of  the 
enamel  organ,  the  ameloblasts,  which,  having  performed  their  function, 
have  filled  with  calco-globulin  and  have  partially  calcified,  becoming 
somewhat  like  that  tissue  which  we  find  on  the  borderland  of  calci- 
fication. 

It  is  probable  that  the  lacunse  found  occupying  a  fissure  between 
the  cusps  of  the  teeth,  in  the  enamel,  are  nothing  more  than  a  little  of 
the  connective  tissue  which  has  become  infolded  and  ossified  before 
the  eruption  of  the  tooth. 


CHAPTER   III. 

DENTAL  HISTOLOGY   WITH  REFERENCE  TO  OPERATIVE 

DENTISTRY.! 

By  Frederick  B.  Xoyes,  B.  A.,  D.  D.  S. 


The  development  of  our  knowledge  of  the  cell  has  had  a  most  pro- 
found effect  upon  the  entire  practice  of  medicine  ;  in  fact,  the  progress  of 
modern  medicine  dates  from  the  studies  of  cell  biology,  the  germ  theory  of 
disease  being  only  one  of  the  phases  of  this  development.  In  terms  of  the 
cell  theory  the  functions  of  the  body  are  but  the  manifest  expression  of 
the  activities  of  thousands  or  millions  of  more  or  less  independent  but 
correlated  centres  of  activity :  if  these  centres  or  cells  perform  their 
functions  correctly,  the  functions  of  the  body  are  normal ;  but  if  they 
fail  to  perform  their  office,  or  work  abnormally,  the  functions  of  the 
body  are  perverted.  In  the  last  analysis,  then,  all  physiology  is  cell 
physiology  ;  all  pathology  cell  pathology.  To  modern  medicine  his- 
tology, or  the  cell  structure  of  the  organs  and  tissues  of  the  body, 
together  with  cell  physiology,  is  the  rational  foundation  of  all  practice. 
This  is  as  true  for  the  dentist  as  for  the  physician  so  far  as  regards  all 
of  the  soft  tissues  of  the  mouth  and  teeth  that  he  is  called  upon  to 
treat  and  handle.  With  caries  of  the  teeth,  the  disease  which  most 
demands  the  attention  of  the  dentist,  the  case  is  somewhat  different. 
Caries  of  the  teeth  is  an  active  destruction,  by  outside  agencies,  of 
formed  materials  which  are  the  result  of  cell  activity  (the  tissues  them- 
selves being  passive).  The  cellular  activities  of  organs  and  tissues  of 
the  body  may  have  an  influence,  but  this  is  only  in  producing  those 
conditions  of  environment  which  render  the  activities  of  the  destructive 
agents  efficient  in  their  action  upon  tooth  tissues.  Though  the  enamel 
and  dentin  are  passive,  we  can  understand  the  phenomena  of  caries 
only  as  we  understand  the  structure  of  the  tissues ;  and  not  only 
must  the  treatment  of  caries  be  based  upon  a  knowledge  of  the 
structure  of  the  tissues,  but  the  mechanical  execution  of  the  treatment 
is  facilitated  by  that  knowledge.  In  the  prei)aration  of  cavities  the 
arrangement  of  the  enamel  wall  is  determined  by  our  knowledge  of 
the  direction  of  enamel  ])risms  in  that  locality,  and  to  a  certain  extent 

!  In  the  prep:iration  of  this  material  I  am  indebted  to  Dr.  G.  V.  Black  for  the  use  of 
his  large  and  valuable  collection  of  microscopic  slides,  and  for  much  advice  and  many 
suggestions. 

93 


94 


DENTAL  HISTOLOGY  AND   OPERATIVE  DENTISTRY. 


the  position  of  the  cavity  margins  must  be  governed  by  our  knowledge 
of  the  structure  of  the  enamel.  In  the  execution  of  the  work  a  minute 
knowledge  of  the  direction  of  enamel  rods  l)ecomes  the  most  imjiortant 
element  in  rapidity  and  success  of  operation. 


From  the  standpoint  of  comparative  anatomy,  the  teetli  are  found 
to  be  not  a  part  of  the  osseous  system,  but  appendages  of  the  skin, 
and  are  to  be  compared  with  such  structures  in  the  body  as  the  nails 
and  the  hair.  The  teeth  are  a  part  of  the  exo-skeleton,  and  their  rela- 
tion to  the  bones  of  the  endo-skeleton  is  entirely  secondary,  for  the  pur- 
pose of  strength,  the  bone  growing  up  around  the  tooth  to  support  it. 

If  we  examine  the  skin  of  such  an  animal  as  the  shark,  we  find 
the  entire  surface  covered  with  small  calcified  bodies  Avhich  are  really 

Fuj.  76, 


Shark's  skull  [Lmnna  cuniubira),  showiiiK  saeeossiuu  of  teeth. 

small  simple  cone-shaped  teeth.  The  mouth  cavity  is  to  be  regarded, 
when  viewed  in  the  light  of  its  development,  as  a  part  of  the  outside 
surface  of  the  body  which  has  been  inclosed  by  the  development  of  the 
neighboring  parts,  and  the  dermal  scales  or  rudimentary  teeth  which 
were  found  in  the  skin  covering  the  arches  which  form  the  jaws  have 
undergone  special  development  for  the  purposes  of  seizing  and  masti- 
cating the  food.  In  the  sim])lest  forms  there  is  only  a  development 
in  size  and  shape  of  these  scales,  and  they  are  supported  only  by  the 
connective  tissue  which  underlies  the  skin.  These  teeth  are  easily  torn 
off  in  the  attempt  to  hold  a  resisting  prey,  and,  as  in  the  shark,  they  are 
constantly  being  replaced  by  new  ones  (Fig.  76).  In  the  more  highly  de- 
veloped forms  there  is  a  growth  of  the  bone  of  the  arch  forming  the  jaw 


DENTAL   TISSUES. 


95 


upward  around  the  bases  of  these  scale-like  teeth,  to  support  them 
more  firmly  and  render  them  more  useful. 

If  we  compare  the  structure  of  the  hair  with  that  of  the  tooth,  we 
find  in  the  case  of  the  hair  a  horny  structure  formed  by  epithelial 
cells  resting  upon  a  papilla  of  connective  tissue  ;  in  the  case  of  the 
tooth,  a  calcified  structure  formed  by  epithelial  cells  resting  upon  a 
papilla  of  connective  tissue  which  is  also  partially  calcified. 

Tlie  relation  of  the  bones  of  the  jaws  to  the  teetli  is  entirely  a  secondary 
and  transient  one.     The  bone  grows  up  around  the  roots  of  the  teeth  to 


Changes  in  the  mandible  with  age  ;  buccal  and  lingual  view. 

support  them,  and  is  destroyed  and  removed  with  the  loss  of  tlie  teeth 
or  the  cessation  of  their  function.  In  this  way  the  development  of  the 
alveolar  process  takes  place  around  the  temporary  teeth  ;  all  of  this  bone 
surrounding  their  roots  is  absorbed  and  removed  with  the  loss  of  the 
temporary  dentition,  and  a  new  alveolar  process  grows  up  around  the 
roots  of  the  permanent  teeth  as  they  are  formed.  This  development  of 
bone  around  the  roots  of  the  teeth  leads  to  the  changes  in  the  shape  of 
the  body  of  the  lower  jaw,  increasing  the  thickness  above  the  mental 
foramen  and  the  inferior  dental  canal.  When  the  teeth  are  finally  lost 
this  bone  is  again  removed  and  the  body  of  the  jaw  is  reduced  in  thick- 
ness from  above  downward  (Fig.  77).  These  phenomena  are  of  im- 
portance in  their  bearing  upon  the  causes  and  treatment  of  diseased  con- 


96  DENTAL  HISTOLOGY  AND   OPERATIVE  DENTISTRY. 

ditions   of  the  teeth,  particuhirly  those  which   involve  the  supporting 
tissues. 

Dental  Tissues. — The  human  teeth  arc  made  up  of  four  tissues 
(Fig.  78): 

1.  The  enamel  covers  the  exposed  portion  of  the  tooth,  or  crown, 
and  gives  the  detail  of  crown  form.  Its  function  is  to  protect  the  tooth 
against  the  wear  of  friction. 

2.  The  dentin  forms  the  mass  of  the  tooth  and  determines  its  class 
form,  the  number  of  cusps  and  the  number  of  roots  being  indicated  by 
the  dentin  form. 

3.  Cementinn  covers  the  dentin  beyond  the  border  of  the  enamel, 
overlapping  it  slightly  at  the  gingival  line  and  forming  the  surface  of 
the  root.  Its  function  is  to  furnish  the  attachment  of  the  fibers  of  the 
])eridental  membrane,  which  fastens  the  tooth  to  the  bone. 

4.  The  jjulp  or  soft  tissue  filling  the  central  cavity  in  the  dentin 
is  the  remains  of  the  formative  organ  which  has  given  rise  to  the  dentin. 
Its  functions  are  the  formation  of  dentin  and  a  sensory  function. 

In  describing  the  structure  of  the  teeth  and  the  arrangement  of  the 
structural  elements  of  the  tissues  directions  are  described  Avith  reference 
to  three  planes  : 

The  mesio-disto-axial  plane,  a  plane  passing  through  the  centre  of  the 
crown  from  mesial  to  distal  and  parallel  with  the  long  axis  of  the  tooth. 

The  bucco-linguo-axial  plane,  a  plane  passing  through  the  centre  of 
the  crown  from  buccal  to  lingual  and  parallel  with  the  loiig  axis  of  the 
tooth. 

The  horizontal  plane,  at  right  angles  to  the  axial  planes. 

The  Supporting  Tissues. — The  human  teeth  are  supported  on  the 
maxillary  bones,  their  alveolar  processes  growing  up  around  the  roots  of 
the  teeth,  so  that  the  roots  fit  into  the  holes  in  the  bone.  The  calcified 
structures  of  the  tooth  and  the  bone  are  not,  however,  united,  but  the 
roots  are  surrounded  by  a  fibrous  membrane,  the  jjer-iclental  membrane, 
or  fte^'ic^inentum,  which  fastens  the  tooth  to  the  bone. 

Enamel. 

The  enamel  differs  from  all  other  calcified  tissues  in  the  nature  of 
the  structural  elements  of  which  this  tissue  is  made  up,  in  the  degree 
of  calcification,  and  in  origin,  being  the  only  calcified  tissue  derived 
from  the  epiblast. 

The  enamel  is  formed  from  an  epithelial  organ  derived  from  the 
epithelium  of  the  mouth  cavity  and  indirectly  from  the  epiblastic  germ 
layer,  while  all  other  calcified  tissues  are  products  of  the  mesoblast. 
In  the  case  of  bone  and  dentin  the  formative  tissue  is  persistent.     It 


ENAMEL. 

Fig.  78. 


97 


Cm. 


Ground  section  of  a  caninu  :  A",  enamel ;  Cm,  cementum  ;  T),  dentin  ;  Pc,  pulp  chamber  :  De,  dento- 
enamel  junction  ;  Ed,  enamel  defect ;  U,  junction  of  enamel  and  cementum  at  the  ginsival  line ; 
Gt,  snmular  layer  of  Tomes.    (Reduced  from  photomicrograph  made  in  three  sections.) 


98  DENTAL  HISTOLOGY  AND    OPERATIVE  DENTISTRY. 

is  possible  in  the  bono  at  least,  therefore,  to  have  degenerative  and  re- 
generative changes,  <»r  the  removal  of  part  of  the  calcium  salts  and  their 
replacement  through  the  agency  of  the  formative  tissue  ;  while  in  the 
enamel  no  such  regenerative  change  is  possible,  as  the  formative  tissue 
disap[)eared  when  the  tissue  was  completed  and  before  the  eruption  of 
the  tooth. 

The  enamel  is  the  hardest  of  human  tissues.  Chemicallv  it  is  com- 
posed of  the  ]ihosphates  and  carbonates  of  calcium  and  magnesium  and 
a  very  small  amount  of  the  fluorids,  water,  also  a  very  small  amount 
of  organic  matter  if  any.^  The  enamel  in  the  natural  condition,  bathed 
in  the  fluids  of  the  mouth,  contains  a  considerable  amount  of  water. 
If  dried  at  a  little  above  the  boiling-point  of  water,  it  gives  up  part 
of  it  and  shrinks  considerably,  so  as  to  crack  in  fine  checks.  If  heated 
almost  to  redness,  it  suddenly  gives  off  from  3  to  5  per  cent,  (of  the 
dry  weight)  of  water  with  almost  explosive  violence.  These  facts  were 
demonstrated  some  years  ago  by  Charles  Tomes,"  and  account  for  most 
of  what  was  formerly  recorded  as  organic  matter  in  old  analyses. 

If  we  observe  under  the  microscope  the  action  of  acids  upon  thin 
sections  of  enamel,  when  the  inorganic  salts  are  entirely  removed,  the 
structure  of  the  tissue  vanishes,  there  being  no  trace  of  organic  matrix 
left  as  in  the  case  of  bone  or  dentin.  In  the  growth  of  l)one  and 
dentin  the  formative  tissue  produces  first  an  organic  matrix  (see  Chap. 
II.,  p.  74)  in  the  form  of  the  tissue,  and  into  this  the  inorganic  salts  are 
deposited,  combining  with  the  organic  substances  of  the  matrix.  This 
union  is  comparatively  weak,  however,  for  by  the  action  of  acids  the 
combination  is  broken  up  and  the  inorganic  salts  are  dissolved  ;  or  by 
heat  the  organic  matter  is  removed,  and  in  either  case  the  form  of  the 
tissue  will  be  maintained. 

In  the  case  of  the  enamel,  the  formative  organ  produces  organic 
substances  containing  inorganic  salts,  and  the  substances  are  arranged 
in  the  form  of  the  tissue  after  the  manner  of  a  matrix  ;  but  finally 
under  the  action  of  the  formative  organ  all  of  the  organic  matter  is 
removed  and  substituted  by  inorganic  salts,  whatever  organic  matter  is 

'  Von  Bibra  gives  the  following-  analysis  of  enamel  : 

Calcinm  phosphate  and  lluorid 89.82 

Calcium  carbonate 4.37 

Magnesium  phosphate 1  -34 

Other  salts 88 

Cartilage 3.39 

Fat 20 

Total  organic 3.59 

"      inorganic 96.41 

*  Journal  of  Phy.tioloyii,  1896. 


ENAMEL. 


99 


found  in  the  fully  formed  tissue  being  the  result  of  imperfect  execution 
of  the  plan. 

The  enamel  is  coni])()sed  of  two  structural  elements,  the  enamel  rods, 
or  prisms,  sometimes  called  enamel  fibers,  and  the  interpeismatic  or 
CEMENTING  SUBSTANCE,  both  of  which  are  calcified.  It  is  to  the  arrange- 
ment of  these  structural  elements  that  the  characteristics  of  the  tissue 
with  \\hich  we  are  most  concerned  in  operative  procedures  are  due. 

While  both  the  prisms  and  interprismatic  substance  of  the  enamel 
are  calcified,  or,  better,  composed  of  inorganic  salts,  the  two  substances 
— that  is,  the  substance  of  the  rods  and  the  substance  between  the  rods 
— show  markedly  different  properties  both  chemical  and  physical.  If 
treated  with  acid,  the  interprismatic  substance  is  acted  upon  more 
rapidly  than  the  rods,  so  that  the  latter  become  more  conspicuous.  By 
this  means  sections  of  the  enamel  may  be  etched  to  render  it  easier  to 
study  the  direction  and  arrangement  of  the  rods.  If  the  action  of  the 
acid  is  carried  far  enough,  the  rods  will  fall  apart  before  they  are  them- 

FiG.  79. 


Enamol  roils  isolatL'd  Ijv  caries.     (About  li 


selves  entirely  dissolved.  Fig.  79  is  from  the  debris  in  a  carious  cavity, 
and  show^s  rods  isolated  by  the  action  of  the  acids  of  caries. 

The  interprismatic  substance  is  not  as  strong  as  the  rods,  so  that  in 
splitting  or  breaking  the  enamel  the  tissue  separates  on  the  lines  of  the 
cementing  sul)stance,  occasionally  breaking  across  a  few  rods  but  fol- 
lowing their  general  direction,  the  lines  running  between  rods,  not  at 
their  centres. 

In  cleaving  the  enamel  the  eiiisel  does  not  enter  the  tissue  sepa- 
rating rod  from  rod,  but  the  edge  engages  with  the  surface,  and   the 


100  DENTAL  HISTOLOGY  AND   OPERATIVE  DENTISTRY. 

force  applied  at  an  acute  angle  with  the  direction  of  the  rods  fractures 
the  tissue  in  the  lines  of  least  resistance.  If  the  edge  be  keenly 
shar]),  it  will  enter  the  tissue  slightly,  and  then  th(!  bevel  acts  as  a 
wedge  in  addition  to  the  force  applied  to  the  shaft  of  the  instrument; 
but  if  the  edge  be  dull,  it  will  rest  across  the  ends  of  many  rods,  will 
not  engage  with  the  surface,  and  the  force  applied  will  break  and 
crumble  the  tissue  but  will  not  cleave  it. 

The  enamel  rods,  or  prisms,  are  long,  slender  prismatic  rods  or 
fibers,  five-  or  six-sided,  pointed  at  both  ends  and  alternately  expanded 
and  constricted  throughout  their  length.  They  are  from  3.4  to  4.5 
microns^  in  diameter,  some  of  them  apparently  reaching  the  entire 
distance  from  the  surface  of  the  dentin  to  the  surface  of  the  enamel  ; 
but  as  the  diameter  of  the  rods  is  the  same  at  their  outer  and  inner 
ends,  and  as  the  crown  surface  is  much  greater  than  the  surface  of  den- 
tin covered  by  enamel,  there  are  many  rods  which  do  not  extend 
through  the  entire  thickness.  These  short  rods  end  in  tapering  points 
between  the  converging  rods  which  extend  the  entire  distance.  To 
express  this  in  terms  of  development :  as  the  formation  of  enamel 
begins  at  the  surface  of  the  dentin,  the  increasing  area  of  crown  sur- 
face requires  more  ameloblasts,  and  as  new  ameloblasts  take  their  place 
in  the  layer  the  formation  of  new  enamel  rods  begins  between  the  rods 
which  were  previously  forming.  These  short  rods  are  most  numerous 
over  the  marginal  ridges  and  at  the  points  of  the  cusps,  and  will  be 
considered  more  fully  in  connection  with  those  positions. 

In  ground  sections  cut  at  right  angles  to  the  direction  of  the  rods  ^ 
the  tissue  has  the  appearance  of  a  mosaic  floor,  the  outline  of  the  rods 
being  more  distinct  if  they  have  been  marked  out  by  treating  the  section 
slightly  with  a(nd  (Fig.  80).  In  longitudinal  sections  (Fig.  81)  the  sides 
of  the  rods  are  not  smooth  and  even  like  the  sides  of  a  lead  pencil,  but 
are  alternately  expanded  and  constricted.  They  are  well  illustrated  by 
taking  balls  of  soft  clay  and  sticking  them  together  one  above  another 
to  form  a  rod,  then  putting  a  number  of  rods  together  so  that  by 
mutual  pressure  they  take  hexagonal  forms.  This  illustrates  also  the 
manner  of  growth  of  the  tissue  in  formation.  The  expansions  and 
constrictions  can  be  seen  in  rods  that  have  been  scraped  from  a  cleaved 
surface  of  enamel,  but  better  by  isolating  rods  by  the  slight  action  of 
dilute  acid  (Fig.  82). 

In  the  construction  of  the  tissue  the  rods  are  so  arranged  that  the  ex- 

'  A  micron  is  tlie  unit  of  microscopic  measurement,  and  is  equal  to  one  one-thousandtli 
of  a  millimeter. 

^  In  describino;  the  direction  of  enamel  rods  they  are  always  considered  as  extending 
from  the  dentin  to  the  surface,  and  the  angle  is  formed  at  the  surface  of  the  dentin  with 
the  locating  plane,  either  horizontal  or  axial. 


ENAMEL. 


101 


pansions  of  one  rod  come  opposite  to  the  expansions  in  the  adjoining 
rods,  and  do  not  interlock  with  their  constrictions.     This  arrangement 


Fic.  80. 


Trails  verse  bccti'jii  of  enamel  rods.    (About  b' 


leaves  alternately  a  greater  and  a  less  amonnt  of  cementing  snbstance 
between  them. 

Fig.  81. 


Enamel  rods  in  thin  etched  section.    (About  SOO  X.) 

AVhen  observed  under  the  microscope,  the  enamel  rods  show  a  char- 
acteristic appearance  of  light  and  dark  lines  running  across  tliem. 
Those  markings  are  similar  to  the  striations  of  voluntary  muscle  fibers, 


102  DENTAL   HISTOLOGY  AND   OPERATIVE  DENTISTRY. 

and  arc  (Icseribed  as  the  striation  of  the  ciiaiiicl.      It  is  seen  not  only  in 
isolated  rods  (Fig.  79),  hut  also  in  sections  ground  in  their  direction  (Fig. 

Fig.  82. 


Eiiii 


tid  l.y  '-(•raping.    (About  <S00  ■  .) 


83).     This  appearance  of  striation  in  the  enamel  is  caused  by  the  alter- 
nate expansions  and  constrictions  of  the  rods  refracting  the  light  like  a 


Fig.  S8. 


Enamel  showing  striation.     (About  1000  X.) 


lens.  In  sections  the  expansions  in  adjoining  rods  are  opjwsite  to  each 
other,  the  difference  in  the  refracting  power  of  the  ]n'isniatic  and  inter- 
prismatic  substances  producing  the  same  effect. 


ENAMEL. 


103 


The  apj>earaiice  of  striation  is  the  record  in  the  fully  formed  tissue 
of  the  manner  of  ii^rowth,  each  dark  stripe,  or  expansion,  in  a  rod 
representing  a  globule  of  partially  calcified  material.  The  ameloblasts 
build  up  the  rods  by  the  addition  of  globule  after  globule,  surrounding 
them  with  a  cementing  substance  and  completing  the  calcification  of 
both.  In  this  sense  the  striation  of  the  enamel  may  be  said  to  record 
the  growth  of  the  individual   rods. 

While  the  enamel  is  a  very  hard  substance  when  its  .structure  is 
complete  and  perfect,  its  most  striking  physical  characteristic  is  a  ten- 
dency to  split  or  crack  in  the  direction  of  its  structural  elements  when 
a  break  has  been  made  in  the  tissue.  While  it  is  difficult  to  cut  across 
the  rods  or  make  an  opening  on  a  perfect  surface,  if  a  break  has  been 

Fig.  84. 


Enamel  showing  direction  of  cleavage.    (About  70  X.) 


established  it  is  comparatively  easy  to  split  off  the  tissue  from  the  sides 
of  the  opening  when  the  rods  lie  parallel  with  each  other.  Fig.  84 
.shows  a  field  of  enamel  illustrating  the  way  in  which  the  tissue  splits 
or  cleaves  in  the  direction  of  the  rods. 

Upon  the  axial  surfaces  the  enamel  rods  are  usually  straight  and 
parallel  with  each  other,  except  where  there  has  been  some  flaw  or 
disturbance  in  development ;  but  upon  the  occlusal  surface,  although 
sometimes  straight,  they  are  very  often  much  twisted  and  wound 
round  each  other,  especially  at  their  inner  ends.  This  difference  in  the 
arrangement  of  the  rods  causes  the  greatest  difference  in  the  feeling 
of  the  tissue  under  cutting  instruments.  Such  a  specimen  of  enamel  as 
shown  in  Fig.  85  can  be  cut  away  easily,  the  tissue  breaking  through 
to  the  dentin  and  splitting  off  in  chuid-:s  ;  while  a  specimen  like  Figs. 
86  and  87  will  not  cleave  if  supported  upon  sound  dentin.     If  tlie  outer 


104  DENTAL  HISTOLOGY  AM>    Ol'KllATIVE  DENTLSTRY 

Fig.  85. 


straight  enamel  rods.     (Al)out  80 X.) 
Fi<;.  SC, 


Gnarled  enamel.     (About  80  X.) 


ENAMEL. 


105 


ends  of  the  rods  are  straight,  they  will  split  part  way  to  the  dentin  (Fig. 
87)  ;  but  where  they  begin  to  twist  round  each  other  they  will  break 
across  the  rods.  If  the  dentin  is  removed  from  under  such  enamel,  it 
will  break  in  an  irregular  way  through  the  gnarled  portion. 

From  a  study  of  the  arrangement  of  the  enamel  rods  in  the  forma- 
tion of  the  crown  it  is  apparent  that  the  plan  is  such  as  to  give  the 

Fig.  87. 


Gnarled  enamel.    (About  50  •  .) 


greatest  strength  to  the  perfect  structure,  and  may  be  likened  to  an  arch. 
At  the  gino;ival  border  the  rods  are  short  and  are  inclined  apically  6  to  10 
centigrades  ^  (20°  to  35°)  from  the  horizontal  plane.     These  short  rods 


'  In  the  Centigrade  division  (he  circle 
is  divided  into  one  hundred  parts,  each 
called  a  centigrade.  One  centigrade  is 
equal  to  3.6  degrees  of  the  astronomical 
circle,  25  centigrades  to  90  degrees,  12j 
centigrades  to  45  degrees.  Tlie  cut  gives 
a  comparison  of  the  two  S3'stems  of  meas- 
uring angles. 


270 


180 
Centigrade  division. 


106 


DENTAL  IHSTOLOGY  AND   OPERATIVE  DENTISTRY. 


arc  ()verlaj)jH'd  lor  a  short  distance  by  tlic  ccinciituiu.  Tliis  inclination 
grows  less  and  less,  and  at  some  ])lacc  in  tlie  gingival  liail'oftlic  middle 
third  of  the  surface  they  arc  in  the  horizontal  plane.  At  this  point  they 
are  also  usually  per])endi('ular  to  the  surface  of  the  enamel.  J^issing 
from  this  point  they  bcconu;  inclined  more  and  more  occliisally  from  the 
horizontal  |)lanc,  at  the  junction  of  the  occ^liisal  and  middle  thirds  about  8 
to  12  centigrades  (28°  to  40°)  in  bicuspids  and  molars,  and  8  to  18 
centigradcs  (28°  to  65°)  in  incisors  and  canines.  In  the  occlusal  third 
the  inclination  increases  rapidly,  and  often  the  outer  ends  of  the  rods 

Fig.  88. 


Diagram  of  enamel  rod  directions,  from  a  photograyih  of  a  buccolingual  section  of  a  superior 

bicuspid. 


are  inclined  more  than  the  inner  ends.  Over  the  point  of  the  cus])s 
and  the  crest  of  the  marginal  ridges  the  rods  reach  the  axial  plane, 
though  they  are  often  very  much  twisted  about  each  other  in  the  inner 
half  of  their  length.  This  position  does  not  always  correspond  with  the 
highest  point  of  the  cusp,  but  is  inclined  slightly  axially  from  that  j)osi- 
tion,  and  corresponds  with  the  highest  ])()int  of  the  dentin  cusp. 

Passing  down  the  central  slope  of  the  cusp,  or  ridge,  the  rods 
become  again  inclined  aAvay  from  the  axial  plane  toward  the  groove,  or 
pit,  leaning  toward  each  other  where  the  two  plates  meet.  The  degree  of 
inclination  of  the  rods  on  the  central  slope  of  the  cusps  de])ends  upon  the 


ENAMEL. 


107 


height  of  the  cusps;  the  higher  the  cusp  the  greater  the  inclination  from 
the  axial  plane.  Fig.  <S8,  a  diagram  from  a  photouraj)h  of  a  biicco- 
lingual  section  of  a  superior  bicuspid,  shows  the  plan  of  arrangement 
and  illustrates  the  arch  principle  in  the  construction. 


Fig.  89. 


Stratification  of  enamel ;  the  cusp  of  a  bicuspid:  Dc,  di.uio-Liiaii,> ;  ,..1..  ;,..i.  l...i.  i  ...unci  defect 
showing  in  the  lieavy  stratification  band;  If/,  interglobular  spaces  in  the  dentin.  (About, 
■lOX.) 


In  the  study  of  longitudinal  sections  of  the  teeth,  one  of  the  most 
conspicuous  structural  features  is  the  stratification  bands,  or  brnvm 
bands  of  Retzinx.  These  bands  are  not  parallel  with  cither  the  outer 
surface  of  the  enamel  or  the  dento-enamel  junction.  They  begin  at  the 
tip  of  the  dentin  cusps  and  sweep  around  in  larger  and  larger  zones. 
These  stratification  bands  are  better  seen  in  comparatively  thick  sec- 
tions, and  are  caused  by  the  varying  amount  of  pigment  deposited  with 


108 


DENTAL   HISTOLOGY  AND   OPERATIVE  DENTISTRY. 


the  calcium  salts  in  the  development  of  the  tissue.  They  record  the 
growth  of  (Miamel  of  the  crown  as  a  whole,  as  each  line  was  at  one  time 
tlie  surface  of  the  enamel  cap.  These  stratifications,  or,  better,  incre- 
mental lines,  are  shown  in  Figs,  89-91. 

At  the  tim(>  the  rod  at  .1  (Fig.  90)  was  comphitely  formed  the  rod  at 
R  was  just  beginning  to  form  at  its  dentinal  end.     From  this  it  would 


Fig.  90. 


Incisor  tip  sliowing  stratification  or  incremental  lines.    Rods  at  A  were  fully  formed  at  the  time 
the  rods  at  B  were  beginning  to  form.    (About  50 X.) 


seem  that  any  structural  defect  due  to  imperfect  development  would  not 
follow  the  direction  of  the  enamel  rods  from  the  surface  to  the  dentin, 
but  would  follow  the  stratification  lines  ;  and  if  these  structural  defects 
influenced  the  penetration  of  caries,  we  should  expect  to  have  the  direc- 
tion of  penetration  modified.  Fig.  89  shows  a  structural  defect  in  the 
enamel  over  a  cusp  following  the  stratification  band,  and  it  will  be 
noticed  also  that  there  is  a  structural  defect  in  the  dentin  at  a  corre- 
sponding position. 


HISTOLOGICAL  REQUIREMENTS  IN  ENAMEL    WALLS. 


109 


HISTOLOGICAL    REQUIREMEXTS     FOR    STRENGTH     IN     ENAMEL 

WALLS. 

1.  The  enamel  must  be  supjwrted  upon  sound  dentin. 

2.  The  rods  whicli  form  the  cavo-surface  angle  must  run  uninter- 
ruptedly to  the  dentin  and  be  supported  by  short  rods,  with  their  inner 
ends  resting  on  the  dentin  and  their  outer  ends  abutting  upon  the  cavity 
wall,  where  they  will  be  covered  in  by  the  filling  material. 

3.  That  the  cavo-surface  angle  be  cut  in  such  a  way  as  not  to  expose 
the  ends  of  the  rods  to  fracture  in  condensing  the  filling  material  against 
them. 

The  first  step,  then,  in  the  preparation  of  an  enamel  wall  is  to  deter- 
mine the  direction  of  the  enamel  rods  by  cleavage  with  a  chisel  or  hatchet. 

Fk;.  ',n. 


Kuaincl  hhuuiiii;  buth  >tiiuUiju  ami  stiutiliealiuu.     (About  80 X.) 

In  Figs.  92  and  93,  No.  1  shoAvs  an  enamel  wall  after  cleaving  the  enamel 
with  a  hatchet.  It  will  be  noticed  that  the  split  has  not  followed  the 
direction  of  the  rods  exactly,  but  has  broken  across  them,  slivering  the 
rods  as  wood  slivers  in  s])litting.  This  would  cause  in  the  cut  surface 
a  whitish,  opaque  appearance.  The  plane  of  the  enamel  wall  should  be 
extended  so  as  to  form  a  small  angle  with  the  plane  of  the  dentin  wall, 
by  shaving  the  surfiice  with  a  very  sharp  hand  instrument.  No.  2  shows 
the  same  wall  after  it  has  been  extended  somewhat ;  but  it  will  be  seen 
that  it  has  not  been  extended  enough,  for  the  rods  forming  the  sur- 
face at  A  do  not  reach  the  dentin,  but  run  out  at  B  on  the  cavity  wall, 
and  that  piece  would  chip  out  in  packing  against  it  or  if  force  came  upon 
the  surface  afterward.     The  angle  should  be  extended  so  as  to  produce 


110 


DENTAL   HISTOLOGY  AND    orEllATIVK   hKyTISTIlY. 


;  X 

7.  s 


<^  ~  -  < 


HISTOLOGICAL  REQIJIREMESTS  IX  ESAMEL    WALLS.  Ill 


Preparation  of  enamel  wall  in  gnarled  enamel :  1.  Enamel  wall  as  cleaved,  showing  breaking 
across  rods  and  slivering  at  n.  2.  Wall  as  smoothed  but  not  extended  to  remove  short  rods 
whose  inner  ends  are  cut  off  at  b.  A.  Wall  extended  and  trimmed  to  a  position  of  strength. 
D,  dentin  ;  De,  dento-enamel  junction  ;  c,  cavo-surface  angle :  b,  point  where  inner  ends  of 

rods  are  cut  off;  a,  slivering  of  the  tissue.    (.-Vbout  50  •  .) 


112 


DENTAL   JIISrOLOGY  AND    OPERATIVE  DENTISTRY 


the  plane  shown  in  No.  3  ;  tlien  the  cavo-surfUce  angle  may  or  may  not 
be  bevelled  as  the  position  demands. 

In  some  positions,  as  on  the  axial  surfaces,  it  is  not  possible  to  ex- 
tend the  plane  of  the  entire  ejiamel  wall  as  described  ;  all  that  can  be 
done  is  to  shave  the  cut  surface,  leaving  the  wall  in  the  direction  of  the 
enamel  rods,  and  then  the  margin  is  strengthened  by  bevelling  the  cavo- 

FiG.  94. 


Occlusal  tisMircj  in  a  sniierior  bicuspid,  showing  direction  of  rods.     (About  H)  y.) 


surface  angle,  so  that  the  rods  forming  the  margin  are  supported  by  at 
least  a  few  rods  which  are  covered  by  filling  material. 

In  cuttins;  out  the  fissures  on  the  occlusal  surfaces  of  molars  and 
bicuspids,  the  rods  are  inclined  centrally  from  the  axial  plane,  as  seen 
in  Fig.  94.  In  opening  a  fissure  the  lines  of  cleavage  will  not  be  in 
the  axial  plane,  but  sloping  inward  toward  the  body  of  the  cusp,  in  the 


HISTOLOGICAL   REQUIREMESTS  IN  ENAMEL    WALLS.         113 


direction  indicated  by  the  direction  of  the  cracks  in  Fig.  94.  The  outer 
ends  of  the  enamel  rods  must  be  shaved  away,  to  bring  the  plane  of 
the  enamel  wall  parallel  witli  the  dentin  wall  or  into  the  axial  plane. 
When  this  has  been  done  a  strong  margin   has  been  formed,  for  the 

Fig.  95. 


■HB 

HiPP^ 

ms^awMTW 

^^H| 

^^H^  V  \   ' 

^^^1 

^^^^^% 

■■J 

H 

1 

1 

,       / 

\ 

r 

! 

-;'.f 

'\  'iv" 

3 

^.^^-"^""'^^^                            \j.^ 

M^ 

'                           y^^                                                                           ^^*    'i 

^ 

y^                                                                                                 ^V 

,\ 

!         / 

K^^, 

ifej^-xi' 

!/ 

■Ili^HLiLVK/ 

Preparation  of  enamtl  walls  in  occ-Iusal  fissure  cavities  (the  same  as  Fig.  94). 

rods  which  form  tlie  point  of  the  cavo-surface  angle  are  supported  by 
the  piece  A,  B,  C(Fig.  95),  made  up  of  rods  resting  upon  sound  dentin 
and  covered  by  the  filling  material.  Often  the  angle  will  be  too  sharp, 
however,  and  the  cavo-surfacc  angle  should  usually  be  bevelled  to  j)ro- 
teet  the  margin  from  accident.  This  illustration  may  be  taken  as  typ- 
ical of  occlu.sal  cavities. 

8 


in  DENTAL    HISTOLOGY  AND    OI'LIIATIVE   DENTISTRY. 


Vu..  on. 


Preparation  of  enamc4  walls  in  a  buccal  cavity  in  a  molar:  G,  gingival  wall ;  0,  occlusal  wall. 

(About  70  X.) 


HISTOLOGICAL  REQUIREMENTS  IN  ENAMEL    WALLS.         115 

Fig.  96  shows  a  cavity  prepared  in  the  buccal  surface  of  an  upper 
molar.  The  occlusal  margin  is  placed  in  the  occlusal  half  of  the  middle 
third,  and  the  gingival  margin  in  the  gingival  half  of  the  gingival  third 


Fig.  97. 


2.  Wall  as  trimmed. 
Preparation  of  occlusal  wall  of  Fig.  96.    (About  70  x.) 

of  the  surfoce.  In  the  occlusal  wall  the  rods  are  inclined  occlu.sally 
about  8  centigrades  (28°)  from  the  horizontal  ]>lane.  After  cleaving, 
the  broken  and  slivered  rods  should  be  shaved  away,  but  the  angle  can- 


116 


DENTAL  HISTOLOGY  AND   OPERATIVE  DENTISTRY. 


not  he  increased  wilhont  making  the  margin  of  filling  material  too  thin  ; 
the  rods  forming  the  margin  shonld  therefore  be  protected  by  bevel- 
ling the  cavo  surface  angle.  At  the  gingival  wall  the  rods  are  inclined 
apically  from  the  horizontal  plane  about  6  centigrades  (20*^).  'J'he 
wall  should  bo  siiaved  in  that  plane,  increasing  the  angle  a  little,  and 
the  cavo-snrface  angle  should  be  bevelled.  Fig.  97  shows  the  occlusal 
enamel  wall  alone,  after  cleaving  and  trimming  into  form.  Such 
enamel    walls   may   be  taken  as  typical  of  axial  surface  cavities,   the 

Fig.  98. 


<:'i^j 


I 


structure  of  enamel  about  a  fissure  :  B,  buccal  side ;  /.,  lingual  side.    (About  70  X.) 

angle   of  the  enamel  with   the  dentin    wall  being  determined  by  the 
direction  of  the  enamel  rods  in  the  position  where  the  margin  is  laid. 

Grooves,  fissures,  and  pits  are  always  positions  of  weakness,  and 
when  a  cavity  appi^oaches  a  groove  or  pit  a  good  margin,  histologically, 
cannot  be  prepared  without  cutting  beyond  it.  Fig.  98  shows  an 
occlusal  fissure  in  a  bicuspid,  which  illustrates  the  conditions  of  struct- 
ure characteristic  of  these  positions.  The  rods  are  inclined  toward 
the  fissure,  and  between  the  bottom  of  the  fissure  and  the  dentin  are 
very  irregular.  If  a  cavity  wall  were  made  to  approach  this  fissure  from 
the  lingual  side,  so  as  to  come  to  the  dotted  line,  the  wall  would  have 
to  be  inclined  6  to  8  centigrades  (20°  to  28°)  from  the  axial  plane  toward 


HISTOLOGICAL  REQUIREMENTS  IN  ENAMEL    WALLS.  117 

the  fissure,  and  then  the  cavo-surface  angle  bevelled,  when  the  condi- 
tions would  be  similar  to  those  in  the  wall  of  an  axial  surface  cavity, 
and  not  as  strong  as  the  location  requires.  Not  only  is  this  true,  but 
it  also  leaves  a  vulnerable  point  next  to  the  margin  of  the  filling — a 
point  of  liability.  Cutting  just  beyond  the  fissure,  the  wall  nuiv  be 
left  in  the  axial  plane  and  have  an  ideally  strong  margin,  and  the 
point   of  liability   is    removed.       To    state   the   conditions    in    general 

Fig.  99. 


■ 

■^'^ 

i 

I 

H 

^^ISh^' '  '^  ^^^^^^^H 

1 

1 

B  A 

Bucco-lingual  section  of  upper  bicuspid.    Enamel  is  broken  from  grinding;  A  to  B,  area  of  weak- 
ness for  enamel  margins.     (About  20  X-) 


terms,  a  .strong  margin  is  more  easily  obtained  where  enamel  rods  are 
inclined  toward  the  cavity  tlian  where  they  are  inclined  away  from  the 
cavity. 

The  points  of  cusps  and  the  crests  of  marginal  ridges  are  positions  of 
strength  in  the  perfect  tissue  ;  but  when  a  cavity  margin  approaches 
them  they  become  points  of  weakness,  because  it  is  impossible  to  sup- 
port  properly  the  rods  Avhich  form  the  margin.     Over  the  marginal 


lis 


DENTAL   HISTOLOGY  AND   OPERATIVE  DENTls'lIlY 


ridges  are  many  short  rods  whieli  do  not  reach  the  dentin,  and  tiiese 
are  usually  very  much  twisted  about  each  otlier,  so  as  to  form  the 
strongest  possible  keystone  in  the  perfect  structure.      In   j)re]>aring  a 


Fig.  100. 


Enamel  over  tip  of  dentin  cusp  :  D,  dentin  cusp.     (About  80  X.) 

margin  in  such  a  position  it  is  impossible  to  have  the  rods  wliich 
form  the  margin  reach  the  dentin  with  their  inner  ends,  and  these 
short  rods  are  sure  either  to  break  in  completing  the  operation  or  to 


HISTOLOGWAL   REQUIREMENTS  IN  ENAMEL    WALLS.  119 

break  out  later.  The  arrangement  of  enamel  rods  in  such  positions  is 
to  be  borne  in  mind,  especially  when  extending  approximal  cavities  in 
incisors  toward  the  lingual  side  and  in  large  pit  cavities  in  incisors.  A 
similar  condition  is  found  over  the  points  of  the  cusps.  Fig.  99  shows 
a  bucco-lingual  section  of  an  upper  bicuspid.  It  will  be  noticed  that 
the  rods  forming  the  point  of  the  cusp  are  not  in  the  axial  plane,  and 


Fi(i.  101. 


Till  'jf  '"I  iuciMir.    I  About  50  X.) 

do  not  reach  the  tip  of  the  dentin  cusp,  but  reach  the  dentin  a  little 
way  down  on  the  outer  slope.  The  enamel  covering  the  tip  of  the 
dentin  contains  many  short  rods,  and  they  are  very  much  twisted  about 
each  other,  so  that  the  area  from  A  and  B  to  the  point  of  the  cusp  is  an 
area  of  weakness  for  the  cavity  margins.  If  the  margin  reaches  this 
area,  the  cusp  must  be  cut  away  and  the  enamel  wall  carried  out  in  the 
horizontal  plane.     Fig.  100  shows  this  area  more  highly  magnified,  and 


120  DENTAL   HISTOLOGY  AND   OPERATIVE  DENTISTIIY. 

illustrates  the  structure.      It  will  be  notit'cd  tluit,  in  grinding,  some  of 
the  short  twisted  rods  have  broken  out  of  the  se(;tion. 

Fig.  101  shows  the  tij)  of"  an  incisor  in  labio-lingual  section,  and  is  of 
interest  in  relation  to  the  formation  of  nuirgins  in  step  cavities  in  in- 
cisors. The  tip  of  this  tooth  has  been  worn  off  in  use.  The  illustration 
shows  tliat  the  great  inclination  of  the  rods  toward  the  axial  plane  in 
the  occlusal  third  of  the  incisors  is  such  as  to  bring  the  wear  almost  at 
right  angles  to  the  direction  of  the  rods. 

Dentin. 

The  structure  of  dentin  is  of  comparatively  little  interest  in  the 
present  consideration,  as  its  histological  forms  do  not  directly  influence 


Fig.  102. 


Dentin  at  dento-enamel  junction,  showing  tubules  cut  longitudinally:  JV,  dentinal  tubules;  D, 

dentin  matrix.    (About  760  X.) 

the  cutting  of  the  tissue  in  the  excavation  of  cavities.  Its  histological 
forms  have,  however,  much  to  do  with  the  penetration  of  caries  and 
with  other  considerations  which  are  of  importance  to  the  intelligent 
practice  of  operative  dentistry. 


DENTIN. 


121 


Dentin  belongs  to  the  connective-tissue  group,  and  is  made  up  of 
a  solid  organic  matrix  impregnated  with  about  72  per  cent,  of  inorganic 
salts  ^  and  pierced  by  minute  canals  or  tubules,  which  radiate  from  a 
central  cavity  which  contains  the  remains  of  the  formative  organ,  or 
pulp.  The  minute  cauals,  or  dentinal  tubules,  are  occupied  in  life 
by  protoplasmic  processes  from  the  odontoblastic  cells  which  form  the 
outer  layer  of  the  pulp.  Dentin  contains  two  kinds  of  organic  matter, 
the  contents  of  the  tubules  and  the  organic  basis  of  the  matrix.  The 
dentin  matrix,  after  the  removal  of  the  calcium  salts  by  acids,  yields 
gelatin  on  boiling  and  resembles  the  matrix  of  bone,  reacting  in  a  similar, 
though  not  identical,  way  with  staining  agents.  The  portion  of  the 
matrix   immediately  surrounding  the  tubules  shows  different  chemical 

Fk;.  KCx 


Dentin  showing  tubules  in  cross-section:  D/,  denlinal  tubules;  i),  dentin  matrix;  S,  shadow  of 
sheaths  of  Neumann.     (About  1150  X-) 

characteristics  from  the  rest  of  the  matrix,  resembling  elastin,  and  re- 
sisting the  action  of  strong  acids  and  alkalies  after  the  rest  of  the 
tissue  has  been  destroyed.  This  portion  of  the  matrix  surrounding  the 
tubules  and  lying  next  to  the  fibrils  is  known  as  the  sJicafhti  of  Neumann. 
The  dentinal  tubules  are  from  1.1  to  2.5  microns  in  diameter,  and 
are  separated  from  each   other  by  a  thickness  of  about  10  microns  of 

'  Von  Bibra  gives  the  following  analysis  of  dentin  : 

(Organic  matter 27.61 

Fat 40 

Calcium  phosphate  and  Huorid 66.72 

Calcium  carbonate 3.36 

Magnesium  phosphate 1.08 

Other  salts 83 


122 


DENTAL   HISTOLOGY  AND    OPERATIVE  DENTISTRY. 


dentin  niati'ix.  Tliis  is  lairly  iinif'onn  thn)U<;li()nt  tlu;  dentin.  Tlie 
character  of  the  tubuk's  is  diffcirent  in  tlie  crown  and  root  portions. 
In  the  crown  tlie  tnbides  hrancli  bnt  little  lhron<>h  most  of  their 
course  ;  but  in  the  outer  j)art,  close  to  the  enamel,  they  branch  and 
anastomose  with  each  other  (juitc  freely.  I  i^.  102  shows  a  held  of 
dentin  just  beneath  the  enamel,  as  seen  with  a  high  jM)wer,  and  shows 
the  diameter  of  the  tubides,  their  branching,  and  the  amount  of  nuitrix 
between  one  tubule  and  the  next.  The  relation  of  one  tubule  to  each 
other  is  shown  also  in  sections  cut  at  right  angles  to  their  direction 
(Fig.  103).    In  the  crown  portion  the  tubules  pass  from  the  pulp  chamber 

Fig.  104. 


Criiwn  111  a  ninl.-ir,  iiirsii)ili;-lal  Sfctimi,  shuwiiiL,'  iiein.'tratKni  ^f  caru  ;-  :    .1,  carits  )iLiiL-truUii,L;  ilen- 
tin;  />,  line  cif  abrasion  ;   7',  iiiilji  cIimiuIjlt.     ;Ahoiit  jn     .) 

to  the  dento-enamel  junction  in  sweeping  curves,  so  as  to  enter  the  pulp 
chamber  at  right   angles  to  the  surface,  and  end   next  to  the  enamel  at 

right  angles  to  that  surface.    This  produces  S-  or  F-shaped     \    or     /] 

curves,  which  are  known  as  the  primary  curves  of  the  tubules.  Through- 
out their  course  the  tubules  are  not  straight,  but  shoAV  a  great  many 
wavy  curves,  known  as  the  secondary  curves.  These  appear  as  waves 
when  seen  in  longitudinal  sections,  but  are  really  the  effect  of  an  open 
spiral  direction,  as  is  seen  by  changing  the  focus  of  the  microscojie  in 
studying  sections  cut   at   right  angles  to  the   direction  of  the  tubules. 


DEyTIX. 
Fig.  105. 


12a 


Ueutiii  from  the  root,  showing  tubuK's  cut  lungitudinally.    (.Vbuut  700  ,\.) 


Fin.  lob 


Dento-enamel  juiu'tion.    (AVjout70X.) 


124 


DENTAL    HISTOLOGY  AND    OPERATIVE  DENTISTRY. 


The  hrniiclics  lliroiighout  their  length  are  few  and  small,  and  are  given 
oiV  at  an  acute  angle  to  the  direction  of"  the  tul)ule;  hut  just  helure  tlie 
enamel  is  reaeiied  tlie  tnhnles  fork  and  hrancli,  producing  an  a[)|)earanee 
similar  to  the  delta  of  a  river.  These  hranches  are  given  otf  from  the 
tubules  for  some  little  distance  hack  from  the  enamel,  and  they  anasto- 
mose with  other  tubules  very  freely.  The  braneiiing  of  the  tubules  in 
their  outer  portion  causes  the  spreading  of  caries  just  beneath  the 
enamel,  the   micro-organisms  growing   through  the  branches  from  tube 


Fig.  107. 


Interglobular  spaces  in  dentin:  7(7,  first  line  of  interglobular  spaces;  7.9',  second  line  of  inter- 
globular spaces.    (About  30  >^.) 

to  tube,  and  so  spreading  sideways  beneath  the  enamel  plates,  and  then 
penetrating  the  dentin  in  the  direction  of  the  tubules.  Fig.  104  shows 
the  penetration  of  caries  in  the  dentin.  It  will  be  noticed  that  in  decay 
starting  at  the  contact  point  there  has  been  more  spreading  under  the 
enamel  than  in  that  starting  at  the  gingival  line,  but  in  both  ])ositions 
the  penetration  has  followed  the  direction  of  the  tubules. 

In  the  root  portion  the  tubules  pass  out  from  the  pulp  canals  at  right 
angles  to  the  long  axis  of  the  tooth  and  pass  directly  out  to  the  cemen- 
tum,  showing  only  the  secondary  curves.    Throughout  their  course  they 


DENTIN. 


125 


give  off  a  great  many  fine  brandies  passing  through  the  matrix  in  all 
directions  from  tubule  to  tubule.  These  branches  are  so  numerous  that 
in  sections  which  have  been  mounted  in  such  a  way  as  to  leave  air  in 
them,  or  if  the  tubules  have  been  filled  with  coloring-matter,  they  give 
the  impression  of  looking  through  a  hazel  bush  ;  or  they  may  be  likened 
to  the  fine  rootlets  of  a  plant.  These  fine  branches  are  shown  in 
Fig.  105,  and  the  character  of  the  dentin  in  the  root  portion  is  to  be 
compared  with  that  in  the  crown  portion  as  shown  in  Fig.  102.     The 

Fig.  108. 


Granular  layer  of  Tomes:  i,  lacunae  of  cementum  ;  G/,  granular  layer  of  Tomes;  7gi,  interglobular 

spaces.    (About  200  X.) 

outermost  layer  of  the  dentin  next  to  the  cementum  contains  many 
small  irregular  spaces,  which  connect  with  the  dentinal  tul)ules  and  give 
to  the  tissue  when  seen  with  low  powers  a  granular  a])]K'arance.  This 
layer  was  first  described  by  John  Tomes  as  the  granular  layer,  and  has 
since  been  usually  called  the  f/r(inu/(ir  layer  of  Toiiief^.  The  spaces  of 
the  granular  layer  are  probably  filled  by  the  enlarged  ends  of  the  den- 
tinal fibrils.  The  same  appearance  is  sometimes  seen  beneath  the  enamel, 
but  is  never  as  well  marked  as  next  to  the  cementum. 

The  dentin  at  the  dento-enamel  junction  seldom  presents  a  smooth 
surface,  but  the  inner  surface  of  the  enamel  plate  shows  rounded  pro- 


126 


DENTAL  HISTOLOGY  AND   OPERATIVE  DENTISTRY. 


jections,  between  which  the  dentin  extends.  In  sections  this  t:;ives  to 
the  dento-en:unel  jnnetion  a  scaUoped  appearance,  as  shown  in  Fij;.  lOG; 
and  often  the  deceptive  a})pearance  of  the  dentinal  tubules  penetratintj: 
for  a  short  distance  between  the  enamel  rods. 

In  many  specimens  made  by  grinding  dried  t(>eth  large  irregular 
spaces  are  very  conspicuous  in  the  dentin.  They  usually  occur  in  lines 
or  zones  at  about  uniform  depth  from  the  surface.  These  have  been 
called  the  interglobular  spaces.  They  are  really  not  spaces  at  all,  but 
are  areas  of  imperfect  development  in  MJiich  the  dentin  matrix  has  not 

Fig.  109. 


Secondary  dentin  :  A,  margin  of  primary  dentin,  showing  a  lew  of  the  tubules  continuing  into  the 
secondary  dentin  ;  P,  pulp  chamber.     (About  SOX.) 

been  calcified.  The  dentinal  tubules  pass  through  them  ^vithout  inter- 
ruption. In  a  dried  specimen  the  organic  matrix  shrinks,  and  the 
resulting  space  becomes  filled  with  the  debris  of  grinding,  so  as  to  give 
the  appearance  of  black  spaces.  Fig.  107  shows  two  quite  distinct  layers 
of  interglobular  spaces,  the  second  much  more  marked  than  the  first ; 
and  in  the  enamel  at  a  position  corresponding  to  the  first  is  seen  an  im- 
l^erfection  of  structure  marked  by  the  very  dark  stratification  band. 
This  is  shown  best  in  the  region  of  the  cusp  (Fig.  89)  from  the  same 
section.  Interglobular  spaces  in  the  root  portion  of  the  dentin  are 
shown  in  Fig.   108,  close  to  the  granular  layer  of  Tomes. 


PULP.  127 

The  formation  of  dentin  is  not  complete  at  the  time  of  eruption  of 
the  tooth,  but  continues  for  an  indefinite  period,  thickening  the  layer  of 
dentin  at  the  expense  of  the  pulp.  When  the  typical  amount  of  den- 
tin has  been  formed  the  growth  ceases,  and  does  not  begin  again  unless 
excited  by  some  irritation  to  the  pulp  or  the  pulp  of  some  other  tooth 
of  the  same  side,  whi(;h  leads  to  the  formation  of  secondary  dentin. 
Secondary  dentin  is  never  as  perfect  in  structure  as  primary  dentin ; 
the  tubules  are  smaller,  fewer,  and  much  more  irregular.  Often  in 
ground  sections  several  periods  of  formation  can  be  determined  by  dif- 
ferences of  structure,  each  deposit  becoming  successively  more  and  more 
imperfect  in  structure.     This  is  shown  in  Fig.  109. 

Pulp. 

The  dental  pulp  is  the  soft  tissue  occupying  the  central  cavity  of  the 
dentin.  It  is  made  up  of  embryonal  connective  tissue  and  contains  a 
large  number  of  bloodvessels  and  nerves.  Like  all  connective  tissues, 
the  intercellular  substance  is  large  in  amount  and  the  cells  are  widely 
scattered  in  tliis  soft,  jelly-like  tissue,  which  contains  but  few  fibers. 
We  recognize  four  kinds  of  cells  in  the  pulp  :  the  odontoblasts,  form- 
ing the  outer  surface  of  the  pulp  next  to  the  dentin;  and  round,  spindle- 
shaped,  and  stellate  connective-tissue  cells. 

AREAXGEMENT    OF    CELLS. 

The  odontoblasts  are  tall  columnar  cells,  sometimes  club-shaped,  and 
in  older  tissues,  which  have  ceased  to  be  functional,  sometimes  becoming 
almost  spherical.  They  form  a  continuous  layer  over  the  entire  surface 
of  the  pulp,  being  everywhere  in  contact  with  the  dentin.  The  layer 
has  been  called  the  membrana  eboris,  or  the  "  membrane  of  the  ivory." 

The  nuclei  of  the  odontoblasts  are  large  and  oval,  containing  a  large 
amount  of  chromatin,  and  are  very  different  from  the  nuclei  of  ordinary 
connective-tissue  cells. 

Three  kinds  of  processes  have  been  described  in  connection  with  the 
odontoblasts  : 

1.  The  dentinal  fibril  processes,  or  fibers  of  Tomes.  These  are  long, 
slender  ])rotoplasmic  processes  projecting  from  the  dentin  end  of  the 
cell  into  a  dentinal  tubule,  and  running  through  the  tubule  to  the  outer 
surface  of  the  dentin.  Usually  there  is  but  one  fibril  extendino;  from 
each  odontoblast,  but  sometimes  two  can  be  seen,  extending  into  two 
tubules.  These  fibrils  can  be  demonstrated  in  decalcified  sections  or 
Ijy  removing  the  pulp  from  a  recently  extracted  tooth  by  cracking  the 
tooth  and  carefully  lifting  the  pulp  out  of  the  pulp  chamber,  and  then 
either  teasing  or  sectioning.     Fig.  110  shows  the  fibrils  projecting  from 


128  DENTAL  HISTOLOGY  AND   OPERATIVE  DENTISTRY. 

the  surface;  but  in  this  section  tlie  cut  was  not  in  the  (Urection  of  the 
h)no:  axis  of  tlie  odontobhists,  hut  obliquely  tliroutih  tiicin.  Fij^.  Ill 
(from  a  photograph  by  Rose)  shows  the  form  of  the  odontoblasts  in  a 

Kk;.  110. 


Odontoblasts.  The  section  cuts  obliquely  through  the  odontoblasts :  F,  fibrils :  .V,  nuclei 
of  odontoblasts;  N',  nuclei  of  connective-tissue  cells;  W,  layer  of  Weil,  not  well  shown. 
(About  80 X.) 

young  tooth  i?i  which  formation  of  dentin  is  actively  progressing,  with 
the  fibrils  in  the  dentinal  tubules. 

2.  Lateral  processes  projecting  from  the  sides  of  the  cells  and  unit- 
ing one  with  another  in  the  formation  of  the  layer, 

3.  Pulpal  processes,  projecting  from  the  pulpal  ends  of  the  odonto- 
blasts into  the  layer  of  Weil. 

The  odontoblasts,  as  the  name  indicates,  are  the  dentin-forming 
cells.  They  superintend  the  formation  and  calcification  of  the  dentin 
matrix,  the  fibril  being  left  behind  surrounded  by  the  formed  tissue. 
Whether  the  fibrils  have  any  share  in  the  formation  and  calcification  of 
the  dentin  matrix  has  been  a  matter  of  controversy. 

The  relation  of  the  fibrils  to  the  transmission  of  sensation  is  also  a 
matter  of  dispute  ;  but  at  present  the  weight  of  evidence  is  that  they 
in  some  way  transmit  impressions  to  the  sensory  nerves  of  the  pulp. 

Just  beneath  the  layer  of  odontoblasts  is  a  zone  which  contains  very 
few  connective-tissue  cells.  In  thin  sections,  especially  in  the  body  of 
the  pulp,  this  appears  as  a  clear  layer  about  half  as  thick  as  the  layer 
of  odontoblasts.     It  is  known  as  the  layer  of  Weil.     Just  beneath  the 


PULP. 


129. 


layer  of  Weil  the  connective-tissue  cells  are  especially  numerous  and 
form  a  more  or  less  distinct  layer  of  closely  placed  cells.  In  the  rest 
of  the  body  of  the  pulp  the  cells  are  about  uniformly  distributed  through- 
out the  intercellular  substance.  These  connective-tissue  cells  are  of  the 
characteristic  forms,  rather  small,  containing  a  small  l)ut  deep-staining 
nucleus,  the  protoplasm  stretching  out  into  slender  projections  in  two 
directions  to  form  the  spindle  cells,  or  in  more  than  two  directions  to 
form  the  stellate  cells.  The  stellate  forms  are  more  common  in  the 
body  of  the  pulp,  the  spindle  form   in  the  canal  portions.     The  round 


Fig.  111. 


"^W 


Odontoblasts  and  forming  dentin:   E,  forming  enamel;  I),  forming  dentin;   0,  odontoblasts; 
Dp,  body  of  dental  papilla.    (From  photomicrograph  by  Rose.) 

cells  are  comparatively  few  in   number,  and  are  probably  young  cells 
which  have  not  yet  acquired  the  adult  form. 


BLOODVESSELS   OF    THE    PULP. 

The  blood-supply  of  the  pulp  is  extremely  rich,  several  arterial  ves- 
sels entering  in  the  region  of  the  apex  of  the  root,  often  through  several 
foramina.  These  large  vessels  extend  occlusally  through  the  central  portion 
of  the  tissue,  giving  off  many  branches  which  break  up  into  a  very  close 
and  fine  capillary  plexus  (Fig.  112).  From  the  capillaries  the  blood  is 
collected  into  the  veins,  which  pass  apically  through  the  central  portion 
of  the  tissue.  A  very  striking  peculiarity  of  the  bloodvessels  of  the  pulp 
is  the  thinness  of  their  walls.     Even  the  large  arteries  show  scarcely  any 


130  DENTAL  HISTOLOGY  AND   OPERATIVE  DENTISTRY. 

Fi(i.  112. 


-,'*jssa« 


Diagram  of  Utv  IiIihmUx-ssuIs  of  the  pulp.     (Stowell.) 

condensation  of  fibrous  tissue  around   tlieni   to  form  the  usual  adven- 
titious layer,  and  usually  contain  but  a  single  involuntary  muscle  fiber 

Fu..  li:i 


*:#    * 


,  * 


*< 


V 


*-4 


%•» 


i« 


A  pulp  bloodvessel,  showing  tin,-  tliiii  wall :  C,  blood  CDrjiustlLS  in  tlio  vessel ;  1)1,  bloodvessel  wall 
showing  nuclei  of  endothelial  cells;  K,  nuclei  of  connective-tissue  cells  in  the  body  of  the 
pulp;  I,  intercellular  substance,  showing  a  few  fibers.     (About  200  >C.) 

representing  the  media,  while  the  walls  of  even  the  large  veins  are  made 
up  of  only  the  single  layer  of  endothelial  cells  forming  the  intima,  and 


PULP.  131 

are  in  structure  like  large  capillaries  (Fig.  113).  This  peculiarity  of  the 
bloodvessel  walls  is  of  great  importance,  as  it  renders  the  tissue  specially 
liable  to  such  pathologic  conditions  as  hyperemia  and  inflammation. 

XEEVE    OF     THE    TULP. 

Several  comparatively  large  bundles  of  medullated  nerve  fibers,  con- 
taining from  six  or  eight  to  fifteen  or  twenty  fibers,  enter  the  pulp 
in  com  pan  V  with  the  bloodvessels  and  pass  occlusally  through  the 
central  j)ortion  of  the  tissue.  These  bundles  branch  and  anastomose 
with  each  other  very  freely.  Most  of  the  fibers  lose  their  medullary 
sheath  before  reaeliing  the  layer  of  AVeil,  in  which  position  they  form  a 
plexus  of  non-nieduUated  fibers  ;  from  these  fibers  free  endings  are  given 
off,  which  penetrate  between  the  odontoblasts.  In  some  cases  these 
have  been  followed  over  on  to  the  dentinal  ends  of  tiie  odontoblasts, 
but  in  no  instance  have  they  been  followed  into  the  dentinal  tubules. 

THE    FUNCTIONS    OF    THE    PULP. 

The  pulp  performs  two  functions,  a  vital  and  a  sensory. 

The  vital  function  is  the  formation  of  dentin,  and  is  performed 
bv  the  layer  of  odontoblasts.  This  is  the  principal  function  of  the 
pulp,  and  it  is  first  manifested  in  the  development  of  the  tooth  before 
the  dentinal  papilla  is  converted  into  the  dental  jnilp  by  being  inclosed 
in  the  formed  dentin.  After  the  tooth  is  fully  formed  the  vital  func- 
tion is  not  manifested  unless  the  pulp  is  stimulated  by  some  excitation 
affecting  trophic  centres  and  which  causes  the  formation  of  secondary 
dentin.  There  are  some  exceptions  where  the  formation  is  entirely 
local. 

The  Sensory  Function. — In  regard  to  sensation,  the  pulp  resembles 
an  internal  organ.  It  has  no  sense  of  touch  or  localization,  and  re- 
sponds to  stimuli  only  by  sensations  of  pain.  The  pain  is  usually 
localized  correctly  with  reference  to  the  median  line,  but,  aside  from 
that,  is  localized  only  as  it  is  referred  to  some  known  lesion.  If  several 
pulps  on  the  same  side  of  the  mouth  and  in  teeth  of  both  the  npj)er 
and  lower  arches  were  exposed  so  that  they  could  be  irritated  without 
im])n'.-sions  reaching  the  peridental  membrane,  and  the  patient  were 
blindfolded,  it  would  l)e  impossible  for  him  to  tell  which  of  the  pulps 
was  touched.  The  \x\\\\  originating  from  a  tooth  pulp  may  be  referred 
to  the  wrong  tooth  or  to  almost  any  point  on  the  same  side  supplied  by 
the  fifth  cranial  nerve. 

The  pulp  is  especially  sensitive  to  changes  of  temperature,  but  is 
incapable  of  differentiating  between  heat  and  cold  ;  this  fact  is  often 
made  use  of  in  differential  diagnoses  (see  Chapter  XVI.).     The  pulj)  is 


132 


DENTAL  HISTOLOGY  AND   OrKRATIVE  DKNTISTIIY. 


also  very  sensitive  to  triuiniatic  and  olK-niiciil  irritations,  even  wiieii 
these  are  conveyed  to  it  tliroii<i:h  the  agency  of  the  dentinal  lihrils.  Dr. 
Huber  has  suggested  '  that  this  transmission  may  be  ac^complislicd  by 
tiie  traumatic  or  chemical  action  upon  the  fibrils  setting  up  metabolic 
changes  in  the  odontoblastic  cells,  which  act  as  stimuli  to  the  sensorv 
nerves  ending  between  the  cells  of  that  layer. 

Cementum. 

The  cementum  covers  the  surface  of  the  dentin  apically  from  the 
border  of  the  enamel,  lapping  slightly  over  the  enamel  at  the  gingival 
margin  (Fig.  114).     It  forms  a  layer,  thickest  in  the  apical  region  and 

Fig.  114. 


D. 


Gingival  border  of  enamel,  showiiiL;  tile  (•(•iiientum  overlapping  it:  £•,  enamel ;  C,  cementum  ;  D, 

dentin.     (About  40  X.) 

between  the  roots  of  bicuspids  and  molars,  and  becoming  thinner  as  the 
gingival  line  is  approached.  The  cementum  resembles  sub})eriosteal 
bone  in  structure,  but  differs  from  it  in  the  character  and  arrangement 
of  the  lacunae  and  in  the  absence  of  Haversian  systems  ;  the  layers,  or 
lamellse,  of  the  cementum  also  are  less  uniform  in  character  than  those 
of  bone. 

The  function  of  the  cementum  is  to  furnish  attachment  for  the 
fibers  of  the  peridental  membrane  which  holds  the  tooth  in  its  position. 
The  surrounding  tissues  are  never  in  ])hysiologic  connection  with  the 
outer  surface  of  the  dentin,  except  to  form  cementum  over  it  or  to 
remove  its  substance  by  absorption  ;  and  when  absorption  of  the  dentin 
'  Devtal  Co,s?Ho,<?,  October,  1<S98. 


CEMENTUM. 


133 


has  occurred  on  the  surfiice  of  a  root  it  is  never  repaired  except  by  the 
formation  of  cementum  to  fill  up  the  cavity  and  reattach  the  membrane. 
The  cementum  is  intermittently  formed  during  the  functioning  of 
the  tooth,  being  added  layer  after  layer  over  the  entire  surface  of  the 
root,  the  difference  in  thickness  of  the  tissue  in  the  gingival  and  apical 
portions  being  chiefly,  though  not  entirely,  due  to  the  difference  in 
thickness  of  each  layer  in  the  two  positions  (Figs.  114,  115).  The 
cementum  on  the  roots  of  newly  erupted  teeth  is  thin,  and  on  the  roots 
of  teeth  of  old  persons  is  thick.     This  continued  formation  of  cementum 

Fig.  115. 


Cementum  near  tbe  apex  of  the  root :  Gl,  granular  layer  of  Tomes  ;  i,  lacuufe  ,  /;,  point  at  which 
fibers  were  cut  off  and  reattached.    (About  54  X.) 


is  due  to  the  necessity  for  change  and  reattachment  of  the  fibers  of  the 
membrane. 

In  the  gingival  portions,  where  the  cementum  is  thin,  the  tissue  is 
clear  and  a])parently  structureless,  and  usually  contains  no  lacuna? ; 
while  in  the  apical  half  and  between  the  roots  the  lacunte  are  numerous. 
In  general,  wherever  the  lamellie  are  thin,  the  lacunae  are  absent ;  but 
where  the  lamellae  are  thick  they  are  found.  The  canalicuH  which 
radiate  from  the  lacunae  are  not  as  regular  as  in  the  case  of  the  lacunie 
of  bone.  Sometimes  they  are  numerous,  sometimes  few ;  they  may 
extend  from  a  lacuna  in  all  directions,  or  they  may  be  confined  to  one 
side,  usually  the  side  toward  the  surface  of  the  cementum  (Fig.  116). 


134  DENTAL  IIISTOLOUY  AND    ()1'KIIAT1V1<:  DENTISTRY 


■|.;  n<; 


Thick  lamella'  of  cementum  with  many  lacunae,  filling  an  absorption  in  dentin:  /„  lacuna;;  H, 
Howship's  lacuna  filled  ;  D,  dentin.    (About  250  >  .) 


Fk;.  11 ' 


Two  fields  of  cementum  bhownijr  penetiatmg  fibers:  Gt,  granular  layer  of  Tomes;  C,  cementum 
not  bhowmg  fibeis  ,  /  ,  penetrating  fibers.    (About  54  X.) 


PERIDENTAL  MEMBRANE.  135 

The  cementum  is  penetrated  through  all  its  layers  by  fibers  of  the 
])ericlental  membrane  which  have  been  imbedded  in  the  matrix  of  the 
tissue  and  calcified  along  with  it.  The  first  layer, — that  is,  the  one  next 
to  the  dentin, — is  usually  structureless  aud  shows  no  fibers  in  it,  at 
least  in  its  inner  half.  In  ground  sections  the  imbedded  fibers  often 
appear  in  a  number  of  layers,  while  they  are  not  apparent  in  the  rest 
of  the  thickness.  This  is  because  just  before  and  just  after  the  forma- 
tion of  the  layers  in  which  they  appear  the  fibers  were  cut  off  and 
reattached,  chauging  their  direction,  so  that  in  the  other  layers  the 
fibers  are  cut  transversely  or  obliquely.  This  is  illustrated  in  Fig.  117. 
These  imbedded  fibers  are  very  numerous  in  some  places.  If  properly 
stained,  the  tissue  seems  almost  a  solid  mass  of  fibers.  In  ground  sec- 
tions these  have  sometimes  been  mistaken  for  minute  canals  from  the 
fact  that  they  are  not  always  as  fully  calcified  as  the  cementum  matrix, 
and  shrinkage  causes  the  appearance  of  little  open  canals. 

Hypertrophies  of  the  cementum  (formerly  often  called  exostoses,  or 
excementoses)  are  very  common.  The  increased  thickness  may  be  of 
one  lamella  or  of  several  lamellre  in  the  region  of  the  hypertrophy,  or 
all  of  the  layers  from  first  to  last  may  take  part  in  it.  Small  local 
thickenings  of  a  single  lamella  are  seen  in  connection  with  the  peri- 
dental membrane  wherever  a  specially  strong  bundle  of  fibers  is  to  be 
attached  to  the  root  to  support  the  tooth  against  some  special  strain. 

Peridental    Membrane, 

The  peridental  membrane  may  be  defiued  as  the  tissue  which  fills 
the  space  between  the  root  of  the  tooth  and  the  bony  wall  of  its 
alveolus,  surrounds  the  root  occlusally  from  the  border  of  the  alveolus, 
and  supports  the  gingivus.  It  has  been  referred  to  under  many  names, 
as  pericementum,  dental  periosteum,  alveolo-dental  periosteum,  etc. 
While  this  tissue  performs  the  functions  of  a  periosteum  for  the  bone 
of  the  alveolus,  it  differs  in  structure  from  the  periosteum  in  any 
position,  so  that  any  name  including  the  word  periosteum  or  implying 
a  double  membrane  should  be  avoided. 

The  peridental  membrane  belongs  to  the  class  of  fibrous  membranes, 
and  is  made  up  of  the  following  structural  elements : 

1.  Fibers.  2.  Fibroblasts.  3.  Cementoblasts.  4.  Osteoblasts.  5. 
Osteoclasts.  6.  Epithelial  structures  which  have  been  called  the  glands 
of  the  peridental  membrane.     7.  Bloodvessels.     8.  Xerves. 

The  peridental  menil)rane  performs  three  functions :  a  physical 
function,  maintaining  the  tooth  in  relation  to  the  adjacent  hard  and 
soft  tissues ;  a  vital  function,  the  formation  of  bone  on  the  alveolar 
wall    and    of  cementum    on    the    surface   of  the    root ;    and  a  sensory 


136 


DENTAL   HISTOLOGY  AND   ODER  ATI  VE  DENTISTRY. 


function,  the    sense  of  touch   for   th(;  tooth  being  exchisively  in    this 
nienihrane. 

The   fibrous  tissue  of  the   incnibrane  is  of  the   white   variety,  and 
may  be  divided  into  two  chisses,  the  principal  fibers  and  the  indifferent  or 


Fig.  lis. 


Diagram  of  the  fibers  of  the  peridental  membrane  :  G,  gingival  portion  ;  Al,  alveolar  portion  ;  Ap, 
apical  portion.    (From  a  photograph  of  a  .section  from  incisor  of  sheep.) 


interfibrous  tissue.     The  principal  fibers  may  be  defined  as  those  which 
spring  from  the  cementum  and  are  attached  at  their  other  end  to  the 


PERIDENTAL  MEMBRANE. 


137 


bone  of  the  alveolar  wall,  to  the  outer  layer  of  the  periosteum  covering 
the  surface  of  the  alveolar  process,  to  the  cenientum  of  the  approximating 


Fig.  119. 


Longitudinal  section  of  peridental  membrane  from  j'oung  sheep,  sliowing  fibers  penetrating 
cementum:  D,  dentin;  C\  cementum,  showing  imbedded  fibers;  F,  fibers  running  to  outer 
layer  of  periosteum  covering  the  alveolar  process  ;  F',  fibers  running  to  the  bone  at  the  i)order 
of  the  process  ;  B,  bone.    (About  80  X.) 


tooth,  or  become  blended  with  the  fibrous  mat  of  the  gum  supporting 
the  epithelium.     They  were  so  called   by  Dr.  Black,  not  only  because 


138 


DENTAL  HISTOLOGY  AND   OPERATIVE  DENTISTRY. 


thoy  form  tlio  ])rincipal  bulk  of  the  tissue,  but  they  also  perform  the 
principal  function  of  the  membrane,  the  support  of  the  tooth  and  sur- 
rounding tissues.  The  interfibrous  tissue,  also  of  the  white  variety  but 
made  up  of  smaller  and  more  delicate  fibers,  is  found  filling  spaces 
between  the  principal  fibers  and  surrounding  and  accompanying  the 
bloodvessels  and  nerves. 

For  convenience  of  description  and  study,  the  peridental  membrane 
is  divided  into  three  portions  :  the(/inf/iva/,  that  portion  which  surrounds 
the  root  occlusally  from  the  border  of  the  alveolar  process  ;  the  alveolar^ 
the  portion  from  the  border  of  the  })rocess  to  the  apex  of  the  root ;  and 

Fi(i.  ]'20. 


/, 


■^  w^; 


■fet' 


M<A 


D. 


N. 


F. 

C. 


/.'. 


Longitudinal  section  <ir  (he  iMi-iilental  mcmhrani^  in  tlie  gingival  portion-  D,  dentin;  N, 
Nasmyth's  membrane;  r,  cunientum;  F,  fibers  supporting  tlie  gingivus;  F^,  fibers  attached 
to  the  outer  layer  of  the  periosteum  over  the  alveolar  process ;  F^,  fibers  attached  to  the  bone 
at  the  rim  of  the  alveolus ;  B,  bone.    (About  30  X-) 

the  apical  portion,  surrounding   the  apex   of  the   root   and  filling  the 
apical  region  (Fig.  118). 

The  principal  fibers  spring  from  the  cementum,  the  cementoblasts 
building  up  the  matrix  around  them  and  then  calcifying  both  matrix 
and  fibers,  in  this  way  implanting  their  ends  into  the  surface  of 
the  root.  In  Fig.  119  the  fibers  are  seen  passing  through  the  last- 
formed  layer  of  cementum.  In  most  positions  the  fibers  as  they  spring 
from  the  cementum  appear  as  well-marked  bundles  of  fine  fibers.  A 
short  distance  from  the  surface  of  the  root  they  break  up  into  smaller 
bundles,  Mdiich  interlace  and   are  reunited  into  larger  buwdles,  to  be 


PEEIDEyTAL  MEMBRA  NE. 


139 


attached  at  their   other  extremity  to  the  bone,  cementum,  or  fibrous 
tissue. 

To  arrive  at  an  understanding  of  the  arrangement  of  the  fibers  of 
the  peridental  membrane,  they  must  be  studied  in  both  longitudinal  and 
transverse  sections.  In  longitudinal  sections  of  the  membrane,  in  the 
gingival  portion  (Fig.  120),  the  fibers  springing  from  the  cementum  at 
the  gingival  line  pass  out  for  a  short  distance  at  right  angles  to  the 
long  axis  of  the  tooth  and  then  bend  sharply  to  the  occlusal,^  passing 

Fig.  121. 


Transverse  section  of  the  peridental  menihrane  in  tlio  giny^ival  portion  (from  sheep):  K.  epi- 
theliuui ;  /'fibrous  tissue  of  gum  ;  B,  point  where  peridental  membrane  fibers  are  lost  in  fibrous 
mat  of  the  gum  ;  P,  pulp  ;  F',  fibers  extending  from  tooth  to  tooth.    (About  30  X.) 


into  the  gingivus  to  support  it  and  hold  it  closely  against  the  neck  of 
the  tooth.  These  fibers  are  most  numerous  on  the  lingual  side,  where 
food  is  brouo;ht  against  the  giufjivus  with  force  in  mastication  and  tends 
to  crush  it  down.  In  the  middle  of  the  gingival  portion  the  fibers  pass 
out  at  right  angles  to  the  axis  and  are  blended  with  the  fibrous  mat  of 
the  gum  on  the  labial  and  Ungual  sides,  or  are  attached  to  the  cementum 
of  the  adjoining  teeth  on  the  approximal  sides.     A  little  farther  from  the 

^  In  describing  the  direction  nnd  inclination  of  peridental  membrane  fibers  they  are 
always  traced  from  the  cementum  to  the  bone,  the  angle  with  tlie  horizontal  plane  being 
formed  at  tlie  surface  of  the  cementum. 


140 


DENTAL   IIISTOLOCY  AND   OPERATIVE  DENTISTRY. 


gingival  line  the  fibers  arc  inclined  slightly  apically,  passing  over  the 
border  of  the  jn'ocess  to  be  attached  to  the  outer  layer  of  the  ])eriosteuni. 
These  fibers  are  specially  large  and  strong.  Just  at  the  rim  of  the 
alveolus  the  fibers  are  inclined  slightly  apically  and  are  inserted  into 
the  bone,  forming  the  edge  of  the  process. 

In  transverse  sections  of  the  membrane  in  the  gingival  portion  (Fig. 
121)  the  fibers  spring  from  the  cementum  in  large  bundles  ;  at  the  centre 
of  the  labial  surface  they  extend  directly  outward,  breaking  uj)  into 
smaller  bundles,  })assing  around  bloodvessels  and  bundles  of  fibers,  and 
blending  with  the  fibrous  tissue  supporting  the  epithelium.  Passing 
niesially  and  distally  toward  the  corners  of  the  root,  the  fibers  swing 
around  laterally  and  pass  to  the  cementum  of  the  next  tooth.     On  the 

Fi(i.  1-22. 


Fibers  at  tlie  border  of  the  alveolar  process  (from  sheep):  D,  dentin  ;  C,  cementum;  F,  fibers  ex- 
tending from  cementum  to  bone ;  Bl,  bloodvessel ;  B,  bone.    (About  80  X.) 


a]>proximal  sides  the  fibers  suddenly  divide  into  smaller  bundles,  M'hich 
wind  in  and  out  around  bloodvessels,  and  bundles  of  fibers  which  pass 
into  the  gingivus  and  are  reunited  into  laroe  l)undles  to  be  inserted  into 
the  cementum  of  the  next  tooth.  On  the  lingual  side  the  arrangement 
is  like  that  of  the  labial,  except  that  the  distance  to  wliich  the  fibers  of 
the  membrane  can  be  followed  before  they  are  lost  in  the  fibrous  mat  of 
the  gum  is  usually  greater  than  on  the  labial. 

In  the  occlusal  third  of  the  alveolar  portion  of  the  membrane  the 
fibers  pass,  at  right  angles  to  the  axis  of  the  tooth,  directly  from  the 
cementum  to  the  bone.  In  this  position  the  fibers  are  large  and  do  not 
break  u]i  into  smaller  bundles,  but  the  original  fibers  can  be   followed 


PERFDEyTAL  MEMBRANE. 


141 


Fig. 123. 


.4/. 


At. 


L;  fc 


Transverse  section  of  the  peridental  membrane  in  the  occlusal  third  of  the  alveolar  portion 
(from  sheep);  3/,  muscle  libers;  Per,  periosteum ;  .4 ^  bone  of  the  alveolar  process;  Pd,  peri- 
dental membrane  libers ;  P,  pulp  ;  P,  dentin  ;  Cm,  cementum.  ' 


142  DENTAL   lUSrOLOGY  AND   OPERATIVE  DENTISTRY. 

uninterruptedly  from  the  eementuni  to  tlie  bono  (Fi^s.  119  and  122). 
In  the  middle  third  the  fibers  are  inclined  occlusally,  and  this  inclina- 
tion increases  as  the  apical  third  is  approached.  In  the  apical  third 
the  inclination  is  greatest,  and  the  fibers  as  they  arise  from  the  cemen- 
tum  are  very  large  and  break  up  into  fim-sha])ed  fiisciculi  as  they  pass 
across  to  the  bone.  In  the  apical  portion  the  fibers  radiate  from  the 
apex  in  all  directions  across  the  apical  region  and  spread  out  in  fan- 
shaped  bundles  like  those  in  the  apical  third  of  the  alveolar  portion. 

In  a  transverse  section  near  the  border  of  the  alveolus  (Fig.  12.'}),  at 
the  centre  of  the  labial  surface  of  the  root,  the  fibers  are  seen  to  extend 
directly  out  from  the  surface  of  the  root  to  the  bone  of  the  process,  ex- 
cepting where  they  are  diverted  to  pass  around  bloodvessels.  Passing 
around  distally  at  the  corner  of  the  root,  the  fibers  swing  laterally  so  as 
to  be  almost  at  a  tangent  to  the  surface  of  the  root,  and  are  inserted 
much  farther  to  the  distal  on  the  wall  of  the  alveolus.  A  similar  ar- 
rangement is  noticed  at  the  other  corners  of  the  root,  though  these 
tangential  fibers  are  usually  more  marked  at  the  distal  than  at  the 
mesial  corners. 

Studying  the  arrangement  of  the  fibers  with  reference  to  the  physical 
function  of  the  membrane,  it  is  seen  to  be  the  best  that  could  be 
devised  to  support  the  teeth  against  the  force  of  mastication  and  to 
support  the  tissues  about  them.  In  the  gingival  portion  the  fibers 
passing  from  tooth  to  tooth  form  the  foundation  for  the  gingivae  between 
the  teeth  filling  the  interproximal  spaces ;  so  that  if  these  fibers  are 
cut  off  from  the  cementum,  by  extending  a  crown  band  too  far,  or  by 
the  encroachment  of  calculary  deposits  beginning  in  the  gingival  space, 
the  gingivus  drops  down  and  no  longer  fills  the  interproximal  S])ace.  In 
the  alveolar  portion  the  fibers  at  the  border  of  the  process  and  those 
at  the  apex  of  the  root  together  su])])ort  the  tooth  against  lateral 
strain,  while  those  in  the  rest  of  the  alveolar  portion  are  so  arranged 
as  to  swing  the  tooth  in  its  socket  and  support  it  against  the  force 
of  occlusion  (Fig.  118).  As  seen  from  the  transverse  section,  the  fibers 
of  the  occlusal  third  of  the  alveolar  portion  are  so  arranged  as  to  sup- 
port the  tooth  against  forces  tending  to  rotate  it  in  its  socket. 

CELLULAR  ELEMENTS  OF  THE  MEMBRANE. 

The  fibroblasts  are  spindle-shaped  or  stellate  connective-tissue  cells 
which  are  found  between  the  fibers  as  they  are  arranged  in  bundles.  In 
sections  stained  with  hematoxylin  they  take  the  stain  deeply,  and  the 
fibers,  which  are  unstained,  are  differentiated  by  the  cells  lying  in  rows 
between  them.  The  number  of  fibroblasts  in  the  membrane  decreases 
with  age.     They  are  large  and  numerous  in  the  membrane  of  a  newly 


PERIDESTAL  MEMBRANE. 


143 


erupted  tooth,  and  comparatively  small  and  few  in  the  membrane  around 
an  old  tooth.  This  is  characteristic  of  fibroblasts  in  other  positions. 
The  fibroblasts  are  shown  as  they  appear  in  a  hematoxylin-stained 
section  with  low  powers  in  Fig.  124,  which  gives  part  of  the  membrane 
in  the  gingival  portion  between  two  teeth.  The  cells  are  seen  as  spindle- 
shaped  dots  which  mark  out  the  fibers  ;  at  F  they  are  seen  in  a  position 

Fig.  124. 


Fibers  and  fibroblasts  from  transverse  section  of  membrane  :  F,  fibers  cut  transversely ;  P",  fibers 
cut  longitudinally,  showing  fibroblasts.    (About  80  X.) 

where  the  fibers  are  cut  transversely.     AVitli  higher  powers  these  cells 
appear  as  in  Figs.  126  and  135. 

The  cementoblasts  are  the  cells  which  form  the  cementum,  and  are 
found  everywhere  covering  the  surface  of  the  root  between  the  fibers 


Fig.  125. 


Cementoblasts.    (Drawing  by  I)r.  Black.) 


which  are  imbedded  in  the  tissue.  While  these  cells  perform  the  same 
function  for  the  cementum  as  the  osteoblasts  do  for  bone,  they  are  in 
form  very  different  from  the  osteoblasts.  The  cementoblasts  are  always 
flattened  cells,  sometimes  almost  scale-like,  and  when  seen  from  above 


144 


DKSTAL  HISTOLOGY  AND   OPERATIVE  DENTISTHY 


are  very  irregular  in  (itilliiie.  This  irregularity  of  outline;  is  eaused  by 
the  cells  fitting  around  the  attached  fibers  of  the  membrane  so  as  to 
cover  the  entire  surface  of  the  eementum  between  the  fibers.  Ficr.  125 
from  a  drawing  by  Dr.  Black,'  shows  several  cementoblasts  as  seen 
when  isolated  by  teasing.  The  cementoblasts  have  a  central  mass  of 
protoplasm  containing  an  oval  nucleus,  and  short  irregular  processes 
which  fit  around  the  fibers  as  these  spring  from  the  surface  of  the 
eementum.      Fig.   126  shows  them   in   section   perpendicularly   to  the 

Fig.  126. 


Ti-aii.-iVLr.sc   section,  sliowinc;   the  rcllulnr  elements:    Fh,  fihrcililasts  ;    Er,  ejiithelial   structures; 
Cti,  cementoblasts  ;  C;»,  eementum  ;  />,  tlentin.     (About  'JOO  X-) 


surface  of  the  root,  where  they  are  crowded  between  the  fibers.  The 
cementoblasts  often  have  processes  projecting  into  the  eementum  like 
those  from  the  osteoblast,  but  processes  projecting  into  the  membrane 
have  never  been  demonstrated. 

In  the  formation  of  the  eementum  occasionally  a  cementoblast  be- 
comes inclosed  in  the  formed  tissue  filling  one  of  the  lacunae,  in  which 
position  it  becomes  a  cement  corpuscle.  i 

^  Periosteum  and  Peridental  Membrane. 


PEBIDENTA  L   MEMBRA  NE. 


145 


Fig.  127. 


H.B. 


Pd.B. 


Border  of  growins;  process  :  Tm,  oemcntum  ;  Prf,  peridental  membrane:  Prf.B,  solid  subperidental 
and  subperiosteal  bone  witli  imbedded  fibers;  J/.s,  medullary  space  formed  by  absorption  of 
the  solid  bone;  //.£,  Haversian-system  bone  without  fibers;  Ptr,  periosteum.    (About  50 X-J 
10 


146 


DENTAL   inSTOLOGY  AND   OPERATIVE  DENTISTRY 


The  osteoblasts  of  the  inenibi-aiic  cover  tlie  siirlace  of"  llic  l)one, 
formiiiii;  tlie  wall  of  the  alveolus,  lyinji;  between  the  libers  which  are 
built  into  the  bone.  In  form  and  function  they  arc  like  the  osteoblasts 
in  attached  portions  of  the  periosteum.  They  form  bone  around  the 
ends  of  the  peridental-membrane  fibers,  buildiui^  them  into  the  sub- 
stance  of  the   bone.       The   bone   thus   formed   over    the   wall   of  the 

Fk;.  12S. 


rd.M. 


Bl.Il 


H.B. 


r'enetrating;  fibers  in  bone  :  Pd.M,  peridental  membrane  ;  OW,  osteoblasts  of  peridental  membrane  : 
062,  osteoblasts  of  medullary  space;  Pd.B,  solid  subperidental  and  subperiosteal  bone  with 
imbedded  fibers;  il/s,  medullary  space  formed  by  absorption  of  the  solid  subperidental  bone 
with  imbedded  fibers ;  H.B,  Haversian-system  bone  without  fibers  built  around  the  medul- 
lary space.    (About  200  X.) 

alveolus  is  like  the  solid  subperiosteal  bone,  and  is  penetrated 
throughout  its  thickness  by  the  imbedded  fibers ;  but,  as  with  the 
subperiosteal  bone,  it  is  constantly  being  penetrated  by  perforating 
canals,  the  solid  bone  being  removed  by  absorption  and  rebuilt  in 
bone  with    Haversian  systems.      This  process  is  shown  in   Fig.   127, 


PERI  DENT  A  L  MEMBRANE. 

Fig.  129. 


147 


■Oc 

B 

■Oc 


—  A 


Osteoclast  absorption  of  bone  over  permanent  tooth:    Oc,  osteoclasts;   B,  bone  of  crypt  wall; 
F,  fibrous  tissue  of  follicle  wall ;  ,1,  ameloblasts.    (About  62  X.) 

Fk;.  180. 


-Oc 


Osteoclasts:  Oc,  o>tri)cl<ists  :  /;,  bone.    (About  66X.) 


148 


DENTAL  HISTOLOGY  AND   OPERATIVE  DENTISTRY. 


a  section  through  a  growing-  jjortioii  of  the  })roccs.s  around  a  j)er- 
inanent  tootli.  A  higher  power  (Fig.  128)  shows  the  i)enetrating 
iibers  and  the  formation  of  Ilaversian-systeni  hone  without  fibers,  in 
the  body  of  the  ])ro('ess. 

The  osteoclasts,  or  niyehtphujucs,  are  bone-destroying  eells  (Fig. 
129);  they  act  not  only  upon  bone,  but  also  u])on  cenientum  and  dentin. 
They  are  oval  cells,  often  as  nuieh  as  30  microns  in  diameter,  and  con- 
tain many  nuclei, — from  two  or  three  to  fifteen  or  twenty.  They  are 
often  called  giant  cells.  The  osteoclasts  are  not  constantly  found  in  the 
membrane,  but  make  their  appearance  whenever  calcified  tissues  are  to 
be  destroyed.  In  order  for  them  to  act  U})on  the  tissues  they  must  lie 
in  contact  with  its  surface,  and  therefore  the  first  step  in  absorption  of 
the  peridental  membrane  is  the  cutting  off  of  the  fibers  imbedded  in 
the  bone  or  cementum.     Where  the  osteoclasts  act  upon  the  surface  of 

Fig.  131. 


liecord  in  the  calcified  tissue  of  an  absorption  repaired  :  D,  dentin  :  Cm,  cementum  filling  absorp- 
tion cavity.    (About  40  X.) 


the  tissue  they  produce  bay-like  excavations,  in  which  they  lie,  and 
which  are  known  as  Howship's  lacunte.  These  excavations  are  shown 
in  Fig.  132,  though  the  osteoclasts  have  disappeared.  In  Fig.  131, 
from  a  ground  section,  the  basin-like  excavations  are  shown  filled  with 
new-formed  cementum,  thus  leaving  in  the  tissue  the  record  of  an 
absorption  repaired.  In  absorption  of  the  roots  of  the  tem})orary  teeth 
the  osteoclasts  are  found  not  only  in  the  membrane  and  attacking  the 
surface  of  the  root,  but  all  through  the  medullary  spaces  in  the  bone, 
removing  the  temporary  alveolar  process. 

When  absorption  is  going  on  at  one  place  on  the  surface  of  a  root 
a  compensating  formation  of  cementum  is  going  on  at  another,  so 
that  not  all  of  the  fibers  of  the  membrane  are  cut  off.     This  is  illus- 


PERIDENTAL   MEMBRANE. 


149 


trated  by  sections  of  temporary  teeth  that  are  ready  to  be  shed  (Fig. 
132). 


Fig.  132. 


Root  of  a  temporary  incisor,  showing  absorption  and  rebuilding  of  cementum  (from  sheep) :  6r,gin- 
givus ;  D,  dentin  ;  Cm,  cementum ;  Ab,  absorption  cavity,  showing  Howship's  lacunse ;  Cni^,  new- 
formed  cementum.    (About  50  X.) 


EPITHELIAL   STRUCTURES    OF    THE    MEMBRANE. 

The  peridental  membrane  contains  celhdar  structures  of  epithelial 
character  which  are  so  conspicuous  that  they  demand  consideration, 
though  their  nature  and  origin  are  not  as  yet  fully  understood. 

These  structures  were  first  well  illustrated   and  described   bv   Dr. 


150  DENTAL  HISTOLOGY  AND   OPERATIVE  DENTISTRY. 


Via.  133. 


Diagram  of  glands  dl'  ]kmiM-iiI:i  :  i.;»  nil.ruiie.    (G.  V.  Black.) 
Fig.  134. 


Epithelial  structures  of  the  peridental  nuinl.riiiic  'ir<.iii  sheeji) :    Fh.  fibroblasts;   Ec,  epithelial 
structures;  Cb,  cemeutoblasts ;  Cm,  cemeiitum  ;  D,  dentin.    (About  468  X.) 


PERIDENTAL   MEMBRANE. 


151 


Black,  ill  his  work  on  the  periosteum  and  peridental  membrane,  in  1887, 
and  were  called  by  him  the  glands  of  the  peridental  membrane.  About 
the  same  time  von  Brunu  '  described  what  are  probably  the  same  struct- 
nres,  and  which  he  regarded  as  embryonal  remains  of  the  inner  layer 
of  the  enamel  organ,  which  he  described  as  growing  down  over  the  sur- 
face of  the  root.     These  structures  appear  as  cords  of  epithelial  cells 

Fig.  135. 


Epitlu'lial  structures  ^from  sheep):  /V*,  tihrdMasts ;  AV,  epitliolial  structures;  r^,  cenientiiblasts; 
C'/n,  cementum  ;  />,  deutiu.     (About  700  X.) 


arranged  in  the  form  of  a  network  winding  between  the  fibers  of  the 
membrane,  very  close  to  the  cementum  and  surrounding  the  root  almost  to 
the  apex.  Their  arrangement  is  illustrated  in  Fig.  133,  a  diagram  by  Dr. 
l^lack.  The  meshes  of  the  net  are  close  in  the  gingival  portion  of  the 
membrane,  but  grow  more  and  more  open  in  the  alveolar  portion.  They 
are  not  confined  to  the  membranes  of  young  teeth  or  the  temporary  den- 
tition, as  Dr.  Black  has  shown  them  in  the  membrane  of  a  tooth  from 
a  man  seventy  years  old,  though,  like  all  of  the  cellular  elements  of  the 

'  Archivf.  mikros.  Anal  ,  1887. 


152 


DENTAL   HISTOLOGY  AND   OPERATIVE  DENTISTHY 


membrane,  they  become  less  nuiiicroiis  as  age  advances.  These  struct- 
nres  are  specially  well  shown  in  the  membranes  of  the  pig  and  sheep. 
Fig.  134  siiows  their  appearance  in  a  transverse  section  of"  the  root  of  an 
incisor  of  a  sheej) ;  here  they  swing  out  from  the  surface  of  the  (lemen- 
tnm  and  l)aci<  again  in  looj)s,  winding  in  and  out  among  the  fibers. 
Studied  witii  higher  powers  (Fig.  1'35),  they  are  seen  t<»  be  made  up  of 
epithelial  cells,  with  large  oval  nuclei  and  reacting  to  tiie  characteristic 
epithelial  stains.  Tliey  are  arranged  in  cords,  thftugh  sometimes  what 
seems  to  be  a  lumen  of  a  gland  tubule  can  be  found  (Fig.  136).     The 


Fi(i.  136. 


^a  yiirrwr^fc'*. 


Epithelial  structures:    Ec,  epitliclial  cord,   M|iiiarcntly  showing  a  lumen; 
Cm,  cementum  ;  D,  dentin.    (About  500  X.) 


b,  cementoblasts ; 


cords  are  invested  with  a  delicate  basement  membrane,  but  no  special 
relation  to  bloodvessels  has  been  demonstrated.  The  attempt  to  show 
their  connection  with  the  surface  epithelium  has  thus  far  failed.  As  the 
gingivus  is  approached  (Fig.  137),  they  seem  to  swing  out  from  the  sur- 
face of  the  root  and  are  lost  between  the  projections  of  the  epithelium 
lining  the  gingival  space.  There  is  evidence  that  these  structures  are, 
at  least  in  some  cases,  of  importance  as  the  primary  seat  of  pathological 
conditions  of  the  membrane. 


PERI  DENT  A  L  MEMBRANE. 
Fig.  137. 


153 


Lon-itudinal  section:  Ep,  epithelium  lining  the  gingival  space;  Gg,  gingival  glan<l,  so  called; 
J>,  dentin  ;  iV,  Nasmyth's  membrane  ;  />«,  duct-like  structure  stretching  away  toward  the  gin- 
givus  from  the  epithelial  cord,  seen  at  Ec ;  Cm,  cementum,  separated  from  the  dentin  by 
decalcification.    (About  50  X.) 


154  DENTAL  HISTOLOGY  AND   OPERATIVE  DENTISTRY. 

Fig.  138. 


Fig.  139. 


Young  and  old  membranes  (from  sheep):  1>,  dentin:  Cm,  cementum:  (';»',  thickening  of  eenien- 
tiim  to  attach  fibers  at  the  corner;  Pd,  peridental  membrane  ;  B,  boue  forming  the  wall  of  the 
alveolus ;  P,  pulp.    (About  80  X.) 


PERIDENTAL   MEMBRANE.  155 

BLOODVESSELS    AND    NERVES    OF   THE    MEMBRANE. 

Bloodvessels. — The  blood-supply  of  the  peridental  membrane  is 
very  abundant.  Several  vessels  enter  the  membrane  from  the  bone  in 
the  apical  region.  These  arteries  branch  and  divide,  forming  a  rich 
network,  from  Avhich  the  capillary  vessels  are  given  off.  The  arterial 
network  is  constantly  receiving  vessels  which  enter  the  membrane 
through  Haversian  canals  opening  on  the  wall  of  the  alveolus,  and  in 
this  wav  the  size  of  the  vessels  passing  occlusally  is  maintained.  Ar- 
terial vessels  also  enter  the  membrane  over  the  border  of  the  process. 
This  double  or  triple  supply  of  the  membrane  is  important,  as  it  main- 
tains the  health  of  the  membrane  when  the  supply  entering  through 
the  apical  region  is  entirely  cut  ofi'  by  alveolar  abscess.  While  the 
arterial  supply  of  the  membrane  is  very  rich,  the  capillaries  in  the 
membrane  are  comparatively  few.  This  is,  however,  a  characteristic 
of  connective-tissue  membranes. 

The  nerves  of  the  peridental  membrane  have  not  been  sufficiently 
studied  to  be  described  in  detail.  Six  to  eight  medullated  nerve  trunks 
enter  the  apical  region  in  company  with  the  bloodvessels,  and  they  re- 
ceive other  trunks  through  the  wall  of  the  alveolus  and  over  the  border 
of  the  process,  but  the  manner  of  their  distribution  and  the  nature  of 
their  endings  are  not  known. 

THE    CHANGES    WHICH  OCCUR    IN    THE    MEMBRANE    WITH    AGE. 

When  a  tooth  is  erupted  the  roof  of  the  bony  crypt  in  which  it  was 
inclosed  in  the  body  of  the  bone  is  removed  by  absorption  and  the 
crown  advances  through  the  opening.  The  diameter  of  the  alveolus  at 
that  time  is,  therefore,  greater  than  the  greatest  diameter  of  the  crown, 
and  the  peridental  membrane  which  fills  the  space  is  very  thick.  By 
the  formation  of  bone  on  the  wall  of  the  alveolus  and  the  formation 
of  cementum  on  the  surface  of  the  root  the  thickness  of  the  membrane 
is  reduced.  In  the  young  membrane  most  of  the  large  bloodvessels  are 
found  in  its  outer  half,  forming  a  rather  defined  vascular  layer  near  its 
centre.  In  the  old  membrane  most  of  the  bloodvessels  are  found  very 
close  to  the  surface  of  the  bone,  often  lying  in  grooves  in  its  surface. 
Both  young  and  old  membranes  are  illustrated  in  Figs.  138  and  139, 
which  are  taken  from  the  temporary  teeth  of  a  sheep,  one  just  after 
eruption  and  the  other  shortly  before  the  time  of  shedding. 


CHAPTER    IV. 

ANTISEPSIS  IN  DENTISTRY. 

By  James  Truman,  D.  D.  S. 


The  importance  of  antisepsis  in  dental  operations  has  not  been 
recognized  as  fully  as  the  subject  would  seem  to  warrant.  This  has 
been  in  part  due  to  the  fact  that  dentists  have  been  accustomed  to  the 
thought  that  cleanliness  in  the  use  of  instruments  would  meet  all  the 
requirements  of  practice.  This  idea  has  been  enforced  by  a  general  im- 
munity from  unpleasant  sequelae  after  operations,  thus  leading  to  a  skep- 
ticism in  regard  to  the  value  of  antiseptic  measures  in  the  oral  cavity. 
This  immunity  has  been  in  part  due  to  the  fact  that  the  fluids  of  the 
mouth  were  supposed  to  have  a  direct  influence  in  preventing  in- 
fection. This  has  never  been  proved  through  laboratory  experiments, 
but  clinical  observation  and  long  experience  have  demonstrated  that 
injuries  in  the  mouth  ordinarily  heal  rapidly,  even  though  these  be  made 
by  infected  instruments.  It  seems  unreasonable  to  suppose  that  a  fluid 
peculiarly  subject  to  fermentation  should  have  this  eifect,  and  this  has 
led  some  to  ascribe  it  to  a  vital  influence.  Miller  ^  says  of  this  :  "  It 
is  a  very  fortunate  provision  that  the  gums  in  a  healthy  state  offer  so 
powerful  a  resistance  to  the  invasion  of  the  germs  of  most  infectious  dis- 
eases. For  this  reason  a  wound  in  the  gums  may  be  followed  by 
scarcely  any  reaction  ^vhatever,  while  a  similar  wound  on  the  hand 
with  the  same  instrument  may  produce  most  disastrous  results.  It  has 
been  attempted  to  account  for  this  fact  on  the  supposition  that  the 
saliva  has  an  antiseptic  action,  in  evidence  of  which  we  are  often  re- 
minded that  dogs  lick  their  wounds,  and  that  these  heal  rapidly. 
I  doubt  if  there  is  anyone  who  would  wish  us  to  believe  that 
the  dead  saliva  has  even  the  slightest  antiseptic  properties,  in  consid- 
eration of  the  fact  that  saliva,  especially  when  it  contains  much  organic 
matter,  readily  putrefies.  If  the  saliva  possesses  any  such  property,  it 
must  be  sought  for  in  its  living  histological  elements, —  i.  e.,  in  the  living 
leucocytes  or  phagocytes."  ^ 

'  Dental  Cosmos,  July,  1891. 

^  For  an  elaborate  study  of  this  problem  see  "  Experimental  Study  of  the  Different 

Modes  of  Protection  of  the  Oral  Cavity  Against  Pathogenic  Bacteria,"  by  Arthur  C. 

Hugenschmidt,  M.  D.,  Dental  Cosmos,  xxxviii.,  p.  797. 

157 


158  ANTISEPSIS  IN  DENTISTRY. 

AVhilc  it  is  true  that  there  exists  a  degree  of  exemption  from  serious 
results,  leading  to  indilTerence  and  careless  management  of  eases,  it  is 
equally  true  that  infection  has  resulted  in  the  experience  of  almost 
every  operator  in  dentistry. 

Prior  to  the  period  Avhen  Lister  announced  that  all  operations  in 
surgery  should  be  performed  antisej)tically,  and  made  modern  surgery 
possible,  this  ignorance  was  excusable  ;  but  at  the  present  time,  with  the 
accumulated  knowledge  in  bacteriology,  it  should  be  impossible  for  any 
dental  operator  to  neglect  the  procedures  under  this  head  considered 
absolutely  essential  for  the  general  surgeon. 

The  difficulties  attending  antisepsis  in  dentistry  far  exceed  those  in 
other  branches  of  surgery.  The  dentist  is  necessarily  obliged  to  meet 
conditions  hourly  that  seem  to  preclude  absolute  freedom  from  sources 
of  contamination.  If  he  were  to  take  the  same  precautionary  measures 
now  regarded  as  necessary  for  the  surgeon,  he  would  find  practice  almost 
impossible.  While  this  is  true,  it  does  not  follow  that  every  eifort 
should  not  be  made  to  approach  absolute  surgical  cleanliness. 

The  usual  methods  employed  to  accomplish  this,  while  valuable  to 
a  limited  extent,  are  by  no  means  equal  to  what  could  readily  be  secured 
without  consuming  much  time  or  patience.  The  dentist  is  usually  sat- 
isfied that  he  has  fulfilled  all  antiseptic  precautions  when  he  has  dipped 
his  instrument  in  some  antiseptic  fluid,  generally  carbolic  acid.  Little 
or  no  attention  is  paid  to  the  possibility  of  infection  from  rubber-dam, 
towels,  hands,  and  the  variety  of  instruments  that  enter  into  dental 
operations.  Some  of  the  latter,  as,  for  instance,  the  separator,  are  more 
liable  to  carry  infection  than  the  excavator,  thq  one  generally  regarded 
as  most  important. 

The  appliances  ordinarily  in  daily  use  are  the  rubber-dam,  excava- 
tors, broaches,  pluggers,  clamps,  ligatures,  separators,  drills,  hand- 
pieces, napkins,  and  forceps.  It  is  safe  to  assume  that  but  few  of  these 
will  receive  any  attention  beyond  ordinary  washing.  The  rubber-dam 
is  too  often  used  as  it  is  furnished  by  the  manufocturer.  If  an  attempt 
at  cleanliness  is  made,  it  consists  in  washing  the  dam  in  cold  or  warm 
water,  this  being  regarded  as  sufficient.  When  it  is  remembered  that 
this  is  passed  between  teeth  and  usually  forced  up  under  gingival 
margins  with  ligatures,  or  clamps,  frequently  lacerating  the  surface,  it 
becomes  evident  that  the  possibility  of  infection  is  always  present. 
If  infection  does  not  occur  from  the  rubber,  it  is  almost  certain  to  pro- 
duce a  wound  in  a  locality  extremely  favorable  for  the  growth  of  patho- 
genic germs.  The  result  is  innumerable  lesions  that  may  extend  to 
pericemental  inflammations.  The  great  increase  in  the  past  twenty- 
five  years  of  gingival  inflammations  subsequent  to  operations  in  mouths 
of  more  than  ordinary  health  must  be  partly  ascribed  to  this  cause. 


SOURCES  OF  INFECTION.  159 

Excavators  ordinarily  receive  the  most  attention,  and  yet,  when  their 
use  is  considered,  they  possibly  require  the  least.  It  is  rarely  necessary 
to  use  the  excavator  outside  of  a  cavity,  where  infection,  if  at  all  pos- 
sible, would  do  the  least  harm,  for  the  continual  washing  of  the  cavity, 
as  the  operator  proceeds,  reduces  the  danger  to  a  minimum.  Broaches, 
and  all  instruments  intended  to  enter  the  pulp  canals,  require  the  most 
careful  attention,  and  this  applies  with  equal  force  to  drills ;  yet  it  is 
feared  that  both  of  these,  loaded  though  they  are  with  septic  matter, 
receive  but  indiiferent  care.  AVhen  the  dangerous  possibilities  which 
may  result  from  this  negligence  are  considered,  it  becomes  a  serious  if 
not  a  criminal  offence.  The  difficulty  in  making  these  instruments  germ- 
free  and  in  keeping  them  from  becoming  contaminated  is  fully  appre- 
ciated ;  yet  tiie  effort  must  be  made,  and  it  is  not  a  difficult  procedure, 
nor  does  it  require  a  large  consumption  of  time — an  important  item  to 
the  dental  operator. 

Pluggers  cannot  be  regarded  as  a  source  of  infection.  They  are 
used  solely  in  connection  with  metal,  and  therefore  strict  cleanliness 
is  all  that  is  absolutely  required.  It  is  fortunate  that  this  is  so,  for 
these  instruments  require  unusual  care  to  protect  them  from  rust. 
Hence  immersion  in  an  antiseptic  fluid  is  deleterious  and  not  re- 
quired. 

Separators — and  under  this  head  are  included  metal  with  screw 
attachments  and  wedges — require  special  attention,  but  probably  receive 
the  least.  They  should  be  made  as  nearly  sterile  as  possible  before 
their  use  upon  a  patient. 

Hand-pieces,  of  the  various  kinds  in  use,  are  probably  the  most 
difficult  to  keep  thoroughly  clean.  While  they  do  not  come  in  direct 
contact  with  the  tissues  of  the  mouth,  they  may  indirectly,  by  contam- 
inating the  hands,  produce  unpleasant  results.  Frequent  taking  apart 
and  boiling  are  essential,  and  should  not  be  omitted. 

Napkins  from  the  oi'dinary  wash  have  been  and  are  used  with  con- 
fidence that  no  bad  results  from  use  can  follow.  If  the  laundry  is  con- 
fined to  the  home,  this  may  ordinarily  be  true,  but  the  indiscriminate 
mingling  of  washes  indulged  in  by  the  commercial  laundryman  is 
always  a  menace  to  health.  Where  napkins  of  the  latter  character  are 
to  be  used  they  should  be  subjected  to  the  sterilizing  process. 

The  chair  occuj)icd  by  a  variety  of  patients  may  be  a  source  of 
disease,  and  should  be  carefully  cleansed,  especial  care  being  taken  with 
the  head-piece.  The  latter  should  be  covered  with  a  clean  napkin,  to 
be  changed  for  every  patient. 

The  cuspidor,  where  the  fountain  is  not  used,  is  ordinarily  an  abom- 
ination, for  here,  if  anywhere,  will  carelessness  be  manifest.  There  can 
be  no  excuse  for  this,  as  thorough  daily  scalding  with  boiling  water  and 


160 


ANTISEPSIS  IN  DENTISTRY. 


Fio.  HO. 


the   use  of  antiseptics  will  keep  it  measurably   free  from   unpleasant 

consequences. 

Glasses  require  to  be  thoroughly  boiled 
both  before  and  after  use.  Boiling  should 
never  be  neglected  with  ejector  tubes,  either 
metal  or  glass,  glass  being  generally  used. 
Hard  boiling  in  water  for  twenty  minutes 
should  be  sufficient. 

The  lancet  is  an  instrument  demanding 
especial  care,  as  it  may  become  a  danger- 
ous source  of  infection.  Before  it  is  used 
the  adjacent  portions  of  the  gum  should  be 
washed  with  an  antiseptic. 

The  forceps  employed  in  extraction 
should  be  so  constructed  as  to  render  the 
blades  readily  separable  at  the  joint,  and 
they  should  be  boiled  in  water  and  soda 
solution  for  an  hour.  The  recorded  cases 
of  infection  from  these  instruments  render 
this  care  imperative  in  all  instances. 

Fig.  140  shows  a  convenient  form  of 
apparatus   for    sterilizing  ordinary   dental 


Downie  steam  sterilizer. 


instruments  by  boiling  soda  solution. 

Oral  Diseases  and  Their  Transmission. 

The  possibility  of  carrying  disease  from  one  person  to  another  seems  so 
self-evident  that  it  ought  not  to  require  more  than  a  word  of  caution, 
and  yet  it  is  clear  that  the  attention  given  to  this  source  of  danger  is  by 
no  means  commensurate  with  the  risks  assumed  constantly  in  practice. 
The  peculiarly  transitory  character  of  much  of  dental  practice  precludes 
the  possibility  of  any  previous  history  of  patients,  and  therefore  every 
one  should  be  regarded  as  a  possible  source  of  infection. 

Diseases  the  result  of  pathogenic  bacteria  independent  of  possible 
external  infection  are  now  in  the  main  well  understood,  but  by  no  means 
equally  appreciated  by  medical  practitioners,  nor  are  they  properly  con- 
sidered by  dental  operators.  Miller '  states  that  "  many  facts  favor  the 
supposition  that  a  considerable  number  of  pathogenic  micro-organisms 
may  thrive  in  the  juices  of  the  mouth  without  showing  in  their  vital 
manifestations  any  distinction  from  the  common  parasites  of  the  oral 
cavity  as  long  as  the  mucous  membrane  remains  intact.  If,  however, 
the  soft  tissues  have  been  wounded,  as  in  extraction,  or  if  the  resistance 
of  the  mucous  membrane  has  been  impaired,  these  organisms  may  gain 
^  The  Micro-organisms  of  the  Human  Mouth,  page  275. 


OBAL  DISEASES  AND   THEIR   TBANSMISSION.  161 

a  point  of  entrance  and  thus  become  able  to  manifest  their  special 
actions."  This  fact,  now  well  recognized,  is  being  constantly  demon- 
strated in  the  use  of  the  various  appliances  that  may,  through  careless 
handling,  injure  the  mucous  membrane.  So  much  is  this  the  case  that 
a  large  proportion  of  gingival  inflammations  have  undoubtedly  had 
their  origin  from  this  cause.  It  has  come  under  the  observation  of  the 
writer  that  injuries  thus  received,  although  apparentlv  unnoticed  bv 
i  entist  or  patient,  have  resulted  in  the  course  of  forty-eight  hours  in 
very  disturbing  pericementitis,  confusing  to  the  operator  and  very  painful 
to  the  patient.  The  necessity  for  such  antiseptic  precautions  here  as  are 
taken  in  general  surgery  is  almost  entirely  overlooked.  Before  placing 
the  coffer-dam,  the  clamp,  or  ligature,  that  portion  of  the  mouth  should 
be  thoroughly  washed  with  an  antiseptic  solution  and  an  effort  made 
to  render  the  appliances  equally  sterile,  or  at  least  to  inhibit  develop- 
ment for  a  definite  period.  When  the  operation  has  been  completed 
the  same  care  should  be  extended  to  the  tooth  and  contiguous  structures. 
The  evidence  is  abundant  that  many  cases  of  pyorrhea  alveolaris  have 
had  their  origin  from  this  careless  indifference  to  accepted  and  necessary 
precautions. 

The  mouth  as  a  source  of  disease  to  the  general  system  does  not 
properly  belong  to  this  article  to  discuss,  but  its  importance  cannot  be 
overlooked.  Dental  writers  have  devoted  much  attention  to  this  sub- 
ject. It  is  for  the  dentist  to  understand  that  he  is,  to  a  large  degree, 
responsible  for  the  general  health  of  his  patient  as  far  as  the  mouth  is 
concerned,  and  he  should  insist  on  prophylactic  measures  that  Mill  at 
least  reduce  this  source  of  disease  to  a  minimum.  The  constant  danger 
of  what  Miller  aptly  calls  "  auto-infection  "  from  the  collection  and 
propagation  of  pathogenic  bacteria  in  the  fluids  of  the  mouth  should 
suggest  to  the  dentist  constant  efforts  to  effect  the  removal  of  all  deposits 
on  the  enamel,  gingival  margins,  tongue,  and  mucous  membrane.  This 
line  of  study  will  bring  about  in  the  future  an  entirely  different  dentistry 
as  to  hygiene  and  prophylaxis  from  that  practised  at  the  present  time. 

The  pulp  of  a  tooth  is  not  ordinarily  regarded  as  a  point  of  in- 
fection, and  yet  it  is  well  known  to  be  a  serious  menace  to  the  health 
of  an  individual.  Israel,  quoted  by  Miller,^  asserts  that  "  the  root 
canal  furnishes  a  point  of  entrance  even  for  the  ray-fungus,  actinomyces, 
and  in  one  case  the  microscopic  examination  revealed  the  elements  of 
this  organism  in  the  canal  of  a  pulpless  tooth."  AVhen  it  is  considered 
that  some  individuals  have  decomposed  pulps  in  a  number  of  teeth  at 
the  same  time,  and  frequently  a  score  of  dead  and  broken  roots,  sending 
out  their  infectious  material,  it  is  not  surprising  that  disease  of  a  serious 
nature   may    supervene.     While  there  is  no  record   of  cases   coming 

^  Tlie  Micro-organisms  of  the  Human  Mouth,  p.  285. 
II 


162  ANTISEPSIS  IX  DENTISTRY. 

within  the  observation  of  the  writer  of  ]iulps  producing  pyemia  directly, 
it  is  a  well-known  ftict,  supported  by  a  long  list  of  recorded  cases, 
that  alveolar  abscess,  with  its  concentration  of  putrid  material,  is  liable 
to  be  followed  by  blood-poisoning. 

There  is  no  question  that  diseases  of  the  digestive  organs,  of  the 
lungs — in  fact,  of  all  the  organs  of  the  body — may  be  produced  by 
infected  material  germinated  in  the  mouth,  and  indeed,  through  sputum 
ejected,  may  affect  individuals  remotely  situated. 

Miller,^  in  considering  this  ])orti()n  of  the  subject,  says  :  "We  know 
that  under  certain  circumstances  saccharomycetes  may  directly  colonize 
in  the  mucous  membrane  of  the  mouth,  and  that  in  the  mouths  of 
enfeebled  individuals  bacteria  may  occasionally  obtain  a  foothold. 
The  mucous  membrane  of  the  mouth  and  pharynx  is  especially  sus- 
ceptible to  the  action  of  certain  germs  of  infection  (those  of  diphtheria, 
syphilis,  etc.),  and  large  portions  of  the  mucous  membrane  and  the  sub- 
mucous tissue  may  be  wholly  destroyed  by  parasitic  influences." 

There  is  a  phase  of  this  subject  that  requires  more  extended  in- 
vestigation. Inflammations  of  the  mouth  are  not  infrequent  where 
great  swelling  is  present.  This  may  be  observed  around  the  lower 
third  molars  Avith  no  explainable  cause  in  dead  pulps,  overlapping 
mucous  membrane,  retarded  eruption,  or  mal-presentation.  It  is  evi- 
dently produced  by  bacterial  invasion,  but  has  not  always  yielded  to 
antiseptic  measures,  and  at  times  has  resulted  in  abscess  entirely  inde- 
pendent of  pnlp  devitalization. 

A  recent  report  of  three  cases  by  Dr.  John  A.  McClain^  in  the 
medical  practice  of  Dr.  M.  G.  Tull  is  interesting  as  indicating  possi- 
bilities. The  first  case  was  an  extensive  swelling  posterior  to  the  lower 
third  molar.  He  could  not  connect  it  with  that  tooth,  and  suspected 
auto-infection.  He  had  cultures  made  with  negative  results.  His 
theory  was  that  it  was  diphtheritic  ;  and,  although  laboratory  evidence 
was  wanting,  he  determined  to  inject  antitoxin.  This  injection  was 
followed  in  twenty-four  hours  by  an  entire  reduction  of  the  swelling. 
All  other  efforts  had  previously  failed  to  effect  any  result.  Two  other 
similar  cases  yielded  to  the  antitoxin  treatment  in  the  same  speedy 
manner.  If  this  can  be  regarded  as  something  more  than  a  coincidence 
in  practice,  it  may  lead  to  an  explanation  of  many  similar  anomalous 
pathological  cases  arising  posterior  to  the  third  inferior  molar,  yet 
apparently  not  connected  with  it.  Similar  conditions  have  been  the 
cause  of  much  uncertain  diagnosis  and  still  more  empirical  treatment. 

The  more  the  w^riter  has  considered  this  subject  the  more  important 
it  has  appeared;  and  he  is  convinced  that,  when  the  proper  prophy- 

^  The  3Iicro-organmns  of  the  Human  Mouth,  p.  295. 
^  International  Dental  Journal,  October,  1900. 


INFECTION  FROM  MOUTH  TO  MOUTH.  163 

lactic  measures  come  into  use  for  the  prevention  of  tuberculosis,  in  all  its 
protean  forms,  antisepsis  of  the  mouth  will  be  given  primary  importance. 

Infection  from  Mouth  to  Mouth. 

Infection  from  mouth  to  mouth  through  instruments  is  a  difficult 
matter  to  prove  by  cases,  but  theoretically  there  can  be  no  cause  for 
disputation.  The  question  will  always  arise,  Was  the  lesion  occasioned 
by  auto-infection  or  by  transmission?  The  answer  can  rarely  be  given 
with  the  assurance  desirable.  In  one  instance,  at  least,  in  the  Avriter's 
experience  the  origin  was  clearly  traceable.  This  was  in  a  patient  of  the 
better  class,  presenting  for  treatment  in  the  clinic  of  the  Dental  Depart- 
ment of  the  University  of  Pennsylvania.  Her  teeth  were  remarkable  for 
structure,  regularity,  and  cleanline-^s  ;  gums  perfectly  healthy.  Necrosis 
of  the  anterior  alveolar  plate  was  threatened  when  first  seen,  and 
finally  resulted  in  the  entire  destruction  of  the  alveolar  border  and  all 
the  anterior  upper  teeth,  but  did  not  involve  the  maxilla.  The  history 
of  the  case  as  given  was  that  a  bicuspid  had  been  extracted  from  the 
right  superior  region  by  a  dentist  notorious  for  his  uncleanly  habits. 
Not  long  thereafter  the  patient  noticed  a  serious  inflammation.  These 
symptoms  indicated  a  syphilitic  infection,  and  the  family  physician  was 
consulted,  who  insisted  that  no  history  of  this  disease  existed  and  that 
infection  must  l)c  the  cause.  The  patient,  through  his  treatment  and 
that  given  locally,  recovered,  but  was  forced  to  wear  an  artificial  sub- 
stitute. 

Cases  of  infection  through  extraction,  either  by  the  forceps  or  after- 
infection  from  the  mouth,  might  be  quoted  almost  indefinitely.  Miller 
reports  case  upon  case — in  fact,  the  accumulation  of  these  has  become 
of  serious  moment ;  and  yet,  in  the  face  of  undisputed  facts,  dentists 
will  continue  to  extract  teeth  frequently  without  any  precautions,  or, 
at  most,  relying  on  simple  washing  of  the  instrument.  Some  German 
writers  contend  that  antisepsis  after  extraction  is  wholly  unnecessary, 
as  the  clot  formed  is  a  sufficient  protection.  This  is  certainly  not  true 
in  all  cases.  It  is  not  always  the  fact  that  a  clot  is  formed,  or  when 
formed  that  it  serves  an  antiseptic  purpose.  One  of  the  most  serious 
cases  that  has  fallen  to  the  writer  to  treat  was  that  of  necrosis  of  the 
superior  maxilla  involving  destruction  of  the  right  side,  taking  in  all 
the  teeth  from  the  third  molar  to  the  lateral,  the  floor  of  the  antrum, 
a  portion  of  the  nasal  bones,  and  half  of  the  hard  palate.  This  was  the 
result  of  the  extraction  of  the  third  molar  by  a  specialist  before  the 
days  of  antisepsis;  whether  it  was  the  result  of  infection  is  difficult 
to  determine.  In  the  opinion  of  the  writer,  no  extraction  should  be 
attempted  until  the  instruments  used  have  been  thoroughly  sterilized  by 
boiling.     Before  the  forceps  are  applied  the  parts  surrounding  the  tooth 


164  ANTISEPSIS  IN  DENTISTRY. 

sliould  be  well  washed  with  an  antiseptic  solution.  After  the  extraction 
the  socket  should  be  syringed  with  sterilized  water,  followed  by 
some  powerful  disinfectant.  In  view  of  the  serious  results  probable  in 
this  ojjcration  there  is  no  longer  any  excuse  for  injuries  resulting  from 
infection,  and  a  suit  for  malpractice  could  be  well  sustained  against  an 
individual  who  had  failed  to  observe  the  well-understood  methods  of 
antisepsis,  while  no  intelligent  practitioner  could  conscientiously  appear 
on  behalf  of  the  defendant. 

External  Infection. 

The  danger  to  the  operator  from  external  infection  from  instruments 
is  a  constant  menace ;  the  constant  use  of  these  with  general  freedom 
from  serious  results,  however,  leads  to  a  degree  of  carelessness  not  war- 
ranted by  the  ever-present  danger  from  wounds.  There  is  more  real 
danger  to  the  operator  from  this  source  than  to  the  patient.  All  the 
excavators,  drills,  and  broaches  are  hourly  in  contact  with  infectious 
matter,  and  it  requires  but  a  slight  wound  to  produce  any  of  the  possi- 
bilities of  blood-poisoning.  The  operator  should  be  on  constant  guard 
in  this  respect,  upon  the  slightest  abrasion  immediately  taking  measures 
to  destroy  all  possibility  of  infection  from  germs  that  may  have  been 
introduced  into  the  wound.  This  should  at  once  be  carefully  washed 
and  an  escharotic  employed,  burning  the  parts.  For  this  purpose  zinc 
chlorid  or  carbolic  acid  is  ])robably  the  best  agent  to  use,  followed  by 
an  antiseptic.  The  latter  should  be  frequently  renewed.  Experience 
has  demonstrated  the  value  of  turpentine  in  the  various  mechanical 
shops  where  this  agent  has  been  for  many  years  in  common  use  for 
wounds  from  rusted  iron,  the  possibility  of  trismns  resulting  from  such 
injuries  being  well  understood.  The  writer  has  used  this  agent,  after 
burning  the  wound,  almost  to  the  exclusion  of  other  antiseptics. 

An  illustration  of  the  ever-present  danger  from  wounds  occurred 
to  a  friend  of  the  writer's,  one  of  the  many  young  women  who  have 
graduated  in  dentistry  in  this  country.  She  accidentally  wounded  her 
hand  by  a  drill,  and  regarded  it  as  of  no  moment.  The  result  Avas  severe 
blood-poisoning  that  for  two  years  kept  her  hovering  between  life  and 
death.  After  suffering  from  severe  metastatic  abscesses,  she  was  finally 
restored  to  partial  health,  but  with  her  constitution  shattered  and  her 
practice  ruined  for  the  time  being. 

Implantation  and  Transplantation. 

Previous  to  the  recognition  of  the  importance  of  antisepsis,  the 
dentists  of  that  period  had  a  very  natural  objection  to  reimplanting 
teeth  ;  the  practice  of  transplantation  was  then  practically  an  unknown 
operation.     The  danger  of  the  operation  was  appreciated,  but  the  reason. 


AGENTS   USED  FOR  STERILIZATION.  165 

was  not  then  comprehended.  When  the  study  of  bacteriology  had  ad- 
vanced to  a  science  through  the  labors  of  Pasteur,  Koch,  and  a  host  of 
investigators,  the  reasons  for  this  fear  were  explained,  and  the  condi- 
tions necessary  to  avoid  unpleasant  results  being  understood,  the  danger 
from  infection  was  changed  to  absolute  security.  It  is,  moreover,  to  be 
ever  borne  in  mind  that  but  for  this  knowledge  implantation  and  trans- 
plantation could  to-day  not  be  practised  without  the  probability  of 
serious  results. 

A  case  illustrating  this  point  occurred  prior  to  the  knowledge  of  anti- 
sepsis in  the  hands  of  a  well-known  dentist.  He  had  removed  three 
teeth  and  successfully  reimplanted  them  for  the  cure  of  a  violent  case  of 
neuralgia  presumably  due  to  calcific  depositions  in  the  pulp  and  about 
the  external  portions  of  the  roots.  Relief  was  so  immediate  that  upon 
return  of  the  pain  another  tooth  was  attempted.  Trismus  followed, 
resulting  in  the  death  of  the  patient.  It  is  safe  to  assume  that  this 
unfortunate  result  could  not  have  happened  under  the  antiseptic  care 
usual  at  the  present  time,  even  imperfect  as  it  frequently  is. 

To  accomplish  antisepsis  in  this  operation  the  greatest  care  is  neces- 
sary. In  transplantation,  teeth  being  procured  from  other  mouths, 
the  danger  is  necessarily  much  increased.  The  method,  adopted  by 
some,  of  immersing  these  teeth  in  various  antiseptic  fluids  cannot  be 
commended.  Miller  says  of  this  : '  "It  is  generally  accepted  that 
the  operator  takes  every  possible  precaution  when  he  allows  the  tooth 
to  lie  for  one-half  to  one  hour  in  a  1  per  cent,  solution  of  carbolic  acid, 
or  in  a  1  :1000  solution  of  bichloride  of  mercury.  ...  In  order  to 
reach  bacteria  that  may  have  penetrated  into  the  lacunae  or  chance  vas- 
cular canals  a  much  longer  action  of  the  antiseptic  is  necessary,  and  to 
be  perfectly  certain  that  we  have  accomplished  our  object  we  should 
have  recourse  to  boiling  water." 

Agents  used  for  Sterilization. 

The  possibility  of  injuring  instruments  has  deterred  dentists  from 
using  many  of  the  agents  recommended  for  the  purpose  of  sterilization. 

Miller-  made  tests  of  various  agents  with  indifferent  results,  with 
the  exception  of  carbolic  acid,  trichlorphenol,  and  mercury  bichlorid. 
The  list  tested  included  the  following : 

Carbolic  acid  in  5  per  cent  aqueous  solution  and  in  pure  form. 

Lysol  in  5  per  cent,  aqueous  solution. 

Trichlorphenol  in  5  per  cent,  aqueous  solution. 

Sublimate  in  5  per  cent,  aqueous  solution  ;  also  in  the  strength  of 
1  :  1000  of  water. 

Benzoic  acid  in  the  strength  of  1  :  300  of  water. 

^  Denial  Cosmos,  July,  1891.  ^  Ibid,  page  520. 


166  ANTISEPSIS  IN  DENTISTRY. 

Potassium  pcnnani^anatc  in  o  per  cent,  aqueous  solution. 

Resorcin  in  10  per  cent,  aqueous  solution. 

Hydrogen  peroxicl  in  10  per  cent,  aqueous  solution. 

Saccharin  in  concentrated  alcoholic  and  acpieous  solution. 

^9-naphthol  in  5  per  cent,  alcoholic  solution. 

Pvoktanin  in  concentrated  aqueous  solution. 

Absolute  alcohol. 

Antiseptin  in  5  per  cent,  aqueous  solution. 

Zinc  sulfate  in  concentrated  aqueous  solution. 

The  essential  oils  in  5  \)or  cent,  emulsions  and  in  pure  form. 

The  three  previously  named,  carbolic  acid,  trichlorphenol,  and 
mercury  bichlorid,  were  the  only  ones  that  gave  any  satisfactory 
results,  and  these  only  partially  so.  In  regard  to  the  rest,  Prof.  Miller 
says  :  "  Thev  all  fall  far  short  of  those  already  mentioned.  The  10  per 
cent,  solution  of  the  peroxid  of  hydrogen  came  next  to  carbolic  acid, 
but  is  considerably  inferior  to  it.  The  essential  oils,  in  emulsions  as 
well  as  in  pure  form,  utterly  failed  to  produce  the  desired  action." 

The  results  obtained  by  Miller  are  not  wholly  in  accord  with  those 
of  some  others.  Charles  B.  Nancrede,  M.  D.,  in  an  article  ^  gives  a 
list  of  agents  which  have  "  proved  most  reliable  clinically,  can  be  resorted 
to  in  any  emergency,  or  are  peculiarly  applicable  to  meet  exceptional 
indications  : " 

Marked  Inhibition.       Complete  Inhibition. 

Mercuric  chlorid 1 : 1,600,000  1 :  300,000 

Oil  of  mustard 1 :  333,000  1 :  33,000 

Thymol      1:86,000 

Oil  of  turpentine 1 :  75,000 

lodin 1  : 5,000  1 :  1,000 

Salicylic  acid 1 :  3,300  1 :  1,500 

Eucalyptol    .        1 : 2,500  1  : 1,251 

Borax ,    .    .      1:2,000  1:700 

Potas.  permanganate 1  :  1.400 

Boric  acid      1 : 1,250  1 :  800 

Carbolic  acid 1 :  1,250  1 :  850 

Quinin 1  :  830  1  :  625 

Alcohol ]  :  100  1  :  12.5 

At  the  time  these  tables  w^ere  prepared  one  agent  not  mentioned  was 
practically  unknown  as  an  antiseptic, — formaldehyd,  or  in  solution 
known  as  formalin. 

Dr.  Elmer  G.  Horton,  B.  S.,  assistant  in  Imcteriology,  Department 
of  Hygiene,  University  of  Pennsylvania,  undertook,  at  the  request  of 
Dr.  Edward  C.  Kirk,  a  series  of  investigations  with  formaldehyd,^  the 
results  of  which  are  given,  omitting  the  details  of  experiments  : 

'  "Treatment  of  Wounds :  Antisepsis  and  Asepsis,"  Surgery  by  American  Authors, 
Park,  page  365. 

^  Dental  Cosmos,  July,  1898. 


AGENTS   USED  FOR  STERILIZATION. 


167 


"  We  employed  the  gas  generated  by  heating  over  an  alcohol  lamp 
a  pastil  which  contained  five  grains  of  paraform.  The  lamp  was  placed 
in  a  tin  box  of  nearly  one  cubic  foot  capacity  .  .  .  (Fig.  141).  Among 
the  instruments  employed  in  the  tests  were  various  chisels,  excavators, 
and  burs.  These  were  boiled,  shown  by  cultural  method  to  be  sterile, 
then  either  dipped  into  bouillon  cultures  or  infected  from  selected  cases 
found  in  the  operative  clinic  of  the  Department  of  Dentistry,  University 
of  Pennsylvania.  After  infection  each  instrument  was  placed  in  a  sterile 
tube  and  kept  at  incubator  temperature  (37.5°  C.)  for  three  hours.  .  .  . 
In  a  single  test  with  moist  instruments  we  found  sterilization  complete. 
After  the  infection  and  subsequent  drying  the  tubes  containing  the  in- 
fected instruments  Avere  separated  into  two  lots,  one  to  be  subjected  to 


Fig.  141. 


Schering's  formalin  sterilizer. 

the  method  of  disinfection  and  the  others  to  be  kept  as  controls,  by 
which  would  be  shown  tlint  no  step  other  than  the  action  of  fornialde- 
hyd  destroyed  the  vitality  of  the  germs.  .  .  .  After  exactlv  ten  or 
fifteen  minutes,  according  to  the  experiment,  the  door  was  opened  and 
the  instrument  quickly  removed.  .  .  .  Each  instrument  (controls  like- 
wise) was  placed  in  a  considerable  amount  of  sterile  bouillon  and  these 
cultures,  together  with  the  subcultures  made  from  them,  observed  for 
at  least  one  week.  ...  In  all  experiments  a  free  growth  developed 
from  the  controls.  .  .  .  The  disinfection  of  instruments  purposely  in- 
fected in  the  clinics  from  cases  of  caries,  pyorrhea,  and  gingivitis  was 
satisfactorily  accomplished  in  every  ca.se.  .  .  .  AVe  conclude  that  infected 
dental  instruments  can  be  di.sinfected  without  injury  in  a  closed  space 
of  less  than  one  cubic  foot,  by  an  exposure  of  fifteen   minutes   to  the 


168  ANTISEPSIS  IN  DENTISTRY. 

fonnaldcliyd  jj^as  generated  from  a  pastil  containinji:;  five  grains  of  para- 
furni  by  heating  the  pastil  over  a  proper  aleohol    lamp." 

In  an  artielo  on  the  ''Uses  and  Limitations  of  Formaldehyd  in 
Dentistry,"  by  Dr.  F.  W.  Low,  Buifalo,  N.  Y.,'  the  effe(^t  of  formal- 
dehyd gas  is  further  given  as  shown  by  a  series  of  experiments  (!on- 
dncted  by  Dr.  Thos.  B.  Carpenter,  assistant  bacteriologist  to  the  Health 
Department  of  the  City  of  Buffalo.  Without  entering  into  detail,  the 
experiments  consisted  of  two  series,  one  of  infected  instruments  and  the 
other  of  clothing  either  of  school-children,  of  nurses,  or  of  the  doctor 
in  the  presence  of  contagion,  to  determine  whether  they  could  be  thor- 
oughly sterilized  by  placing  them  over  night  in  a  wardrobe  exposed  to 
the  fumigation  of  the  lamp  used. 

The  conclusion  of  Dr.  Carpenter  was  that  "Tiiis  apparatus  can  be 
relied  upon,  after  an  exposure  of  from  ten  to  fifteen  minutes,  to  destroy 
thin   layers   of  the  common,   non-sporulating  pathogenic  organisms." 

In  regard  to  the  second  series  of  experiments  with  clothing,  he  says  : 
"  It  is  evident,  therefore,  that  twelve  hours'  exposure  to  the  action  of 
this  lamp  in  a  closet  of  15.8  cubic  feet  capacity  is  sufficient  for  effec- 
tive surface  disinfection,  the  most  resistant  pathogenic  bacteria  being 
destroyed." 

A  third  series  of  experiments  was  undertaken  with  scaling  instru- 
ments taken  from  the  instrument-cases  from  several  operators,  including 
that  of  Dr.  Low.  The  result  of  this  elaborate  experimentation  is  thus 
summed  up  by  the  author  :  "  Every  set,  except  the  one  irJiere  the  tvhole 
case  was famif/ated  over  night,  produced  some  cultures;  but  not  one  set 
developed  a  culture  of  pathogenic  organisms." 

''The  Low  lamp  consists  of  an  asbestos-lined  tray,  or  box,  sup- 
ported on  legs  {A)y  with  an  opening  in  the  bottom  to  admit  the  chim- 
ney of  the  lamp,  the  purpose  of  which  is  to  conduct  the  fumes  of  the 
formaldehyd  gas  into  the  tray  and  upon  the  instruments  it  is  desired 
to  sterilize. 

"The  working  parts  of  the  lamp  are  shown  in  the  illustration.  An 
ordinary  alcohol  wick  is  drawn  into  the  wick  tube.  To  place  the  lamp 
(B)  in  operation  fill  it  with  ivood  alcohol,  grain  alcohol  being  incapable 
of  generating  formaldehyd.  Adjust  cone-shaped  platinum  coil  so 
that  it  just  touches  the  top  of  the  wick.  Light  the  latter;  place  on 
chimney,  and  after  a  few  seconds'  waiting  blow  out  the  flame.  If  the 
cone  be  in  proper  adjustment  to  the  wick,  it  will  be  observed  that  the 
coil  glows  like  a  live  coal,  but  there  is  no  flame  or  dangerous  heat. 

"Having  the  lamp  in  operation,  as  described,  and  the  tray  properly 
adjusted  to  set  over  it,  as  in  illustration,  instruments  may  be  placed 
in  the  tray  and  allowed  to  remain  for  ten  minutes,  a  sufficient  time  to 

1  Denial  Cosmos,  February,  1900. 


AGENTS   USED  FOR  STERILIZATION. 


169 


effect  sterilization.     When  taken  out  they  should  be  wiped  dry  with  a 
surgically  clean  napkin  or  towel. 

"To  stop  the  fumigation  going  on  in  the  lamp,  remove  the  chimney 
and  slide  the  cage  high  up  on  the  tube,  so  that  the  platinum  cone  no 
longer  touches  the  wick,  then  allow  it  to  cool  before  replacing  chimney." 

Fro.  142. 


Low's  formaldehyd  lamp :  /I,  for  dental  use ;  ii,  for  household  use;  C,  locked  cage  for  public  places. 

AVhile  it  is  not  difficult  for  the  average  dentist  to  use  formaldehyd 
as  a  disinfectant,  it  will  probably  be  considered  a  useless  expenditure 
of  time,  and,  therefore,  boiling  in  water  and  soda  for  at  least  twenty 
minutes  seems  the  more  feasible  and  is  equally  certain  in  the  results. 

The  dentist  who  aims  to  k('('[)  only  aseptic  instruments  should  have 


170  ANTISEPSIS  IN  DENTISTRY. 

two  sets  in  daily  use.  When  through  with  one  patient  the  instruments 
should  undergo  the  boiling  process  in  preparation  for  the  next.  At 
the  close  of  the  day  all  instruments  used  should  be  thoroughly 
boiled  and  dried  upon  aseptic  napkins  and  placed  in  the  case.  The 
possibility  of  infection  from  the  latter  must  not  be  overlooked.  The 
first  and  second  set,  therefore,  used  the  next  day  for  the  first  time  should 
be  either  boiled  again  or  each  instrument  dipped  into  an  antiseptic  fluid. 
For  this  ])ur})ose  the  writer  prefers  a  strong  solution  of  hydronaphthol 
(8  grains  to  the  ounce  of  alcohol)  to  the  carbolic-acid  solution  ordinarily 
used.  With  this  care  all  danger  of  infection  can  be  removed  and  the 
dentist  relieved  of  all  legal  responsibility. 

The  preparation  of  the  hands  previous  to  operations  is  most  per- 
plexing to  the  conscientious  operator,  whether  this  be  in  surgery  or 
dental  practice.  In  order  that  dental  operators  may  be  able  to  arrive 
at  definite  conclusions  in  regard  to  what  may  be  required  of  them  in 
their  daily  work,  the  following  quotation  is  given  from  Nancrede's 
article  ^  on  the  care  required  in  hospital  surgical  practice  : 

"  Sterilized  water  as  hot  as  can  be  borne  should  be  employed.  This 
must,  of  course,  be  never  cooled  by  the  addition  of  any  but  cold  ster- 
ilized water.  .  .  .  The  nail-brush,  best  made  of  vegetable  fiber,  must 
be  always  carefully  rinsed  after  use  and  sterilized  by  heat  for  each 
operation.  .  .  .  Although  it  is  alleged  that  all  soaps  made  by  heat  are 
sterile — indeed,  that  potash  soap  is  an  active  germ-inhibitor  in  the  pro- 
portion of  1  :  5000 — yet  it  is  the  part  of  prudence  to  combine  with  the 
soft  soap  5  per  cent,  of  hydronaphthol  or  thymol,  to  insure  that  the 
soap  itself  is  free  from  germs.  After  thoroughly  rubbing  into  the  hands 
and  arms  and  under  the  nails  abundance  of  soap,  the  nail-brush  and 
hot  water  must  be  vigorously  used,  especially  beneath  and  around  the 
nails,  for  from  two  to  five  minutej.  Next,  carefully  clean  the  nails  and 
around  them  with  a  nail-cleaner.  Removal  of  all  grease  can  now  be 
effected  by  ether  or  by  immersion  in  alcohol,  or  best  by  alcohol  contain- 
ing 5  per  cent,  of  dilute  acetic  acid,  which  should  be  rinsed  otf  thor- 
oughly with  sterilized  water,  removing  the  last  traces  of  soap.  Finally, 
the  hands  should  be  immci'sed — not  merely  dipped — in  a  1  :  2000  mer- 
curic chlorid  solution  for  not  less  than  three — preferably  five — minutes. 
Instead  of  corrosive  sublimate  solution,  ordinary  mustard  flour  mixed 
in  the  hands  into  a  thin  paste  with  sterilized  water,  used  with  gentle 
friction  for  two  or  three  minutes  and  then  removed  with  sterilized 
water,  will  prove  a  most  successful  germicide." 

AVhile  the  foregoing  may  serve  as  a  basis  for  comparison,  it  would 
be  wholly  impracticable  in  dental  practice.  It  remains,  however,  that 
the  hands  of  the  dental  operator  should  be  the  subject  of  constant  care. 

'  Loc.  cit. 


AGENTS   USED  FOR  STERILIZATION.  171 

Nails  should  be  kept  short  and  scrupulously  clean.  It  seems  to  the 
writer  that  the  use  of  a  good  potash  soap  and  nail-brush,  with  bathing  the 
hands  in  alcohol,  will  be  amply  sufficient  unless  working  on  a  syphilitic 
patient,  when  more  effective  methods  must  be  resorted  to,  and  there  can 
be  nothing  better  than  the  mode  described  by  Dr.  Nancrede. 

The  conclusions  to  which  the  writer  has  arrived  from  experience  and 
study  of  the  subject  may  be  sunmied  up  briefly  as  follows  : 

1.  Dipping  instruments  in  an  antiseptic  fluid  previous  to  operating, 
while  beneficial,  is  not  sterilization. 

2.  That  boiling  with  soda  is  for  the  dentist  the  most  convenient 
means  of  sterilizing  instruments  without  injury,  while  the  more  recently 
introduced  method  of  formaldehyd  antisepsis  is  a  dry  process  that  does 
not  rust  or  injure  steel  instruments  and  is  also  promptly  effective. 

3.  That  the  ordinary  methods  used  to  effect  sterilization  in  surgical 
practice  are  not  possible  in  dentistry,  but  that  every  dentist  is  legally 
and  morally  bound  to  live  as  near  to  the  rules  of  antisepsis  as  is  possi- 
ble with  the  demands  of  a  daily  practice. 


CHAPTER  V. 

THE  EXAMINATION  OF  TEETH  PRELIMINARY  TO  OPERA- 
TION—METHODS, INSTRUMENTS,  APPLIANCES— RECORD- 
ING RESULTS,  ETC. 

By  Louis  Jack,  D.  D.  S. 


The  Operator. 

The  attitude  of  the  body  of  the  dental  operator  has  considerable 
influence  upon  the  ease  with  which  the  various  positions  required  in 
operating  may  be  assumed,  and  also  has  some  bearing  upon  the  free- 
dom of  his  hands. 

The  erect  position  should  be  maintained  as  far  as  possible  and  the 
preponderance  of  the  weight  should  be  sustained  upon  the  balls  of  the 
feet.  This  secures  equilibrium  and  enables  movements  to  be  made 
with  little  embarrassment.  The  shoulders  should  be  held  well  back  in 
order  that  the  arms  may  not  be  cramped,  and  to  permit  the  respira- 
tion to  be  carried  on  deeply  and  with  quietness.  For  obvious  reasons 
tlie  breathing  should  be  deep,  slow,  and  always  through  the  nose. 

The  precise  use  of  the  fingers  requires  that  in  each  application  of  the 
instrument  a  rest,  as  a  fulcrum  or  base  of  action,  should  be  used,  and 
when  force  is  to  be  applied  a  f/uarcJ  in  addition  is  necessary  to  give 
security  to  the  moyement  of  the  hand.  The  positions  of  the  rest  and 
the  nature  of  the  guard  required  in  operating  are  various,  depend- 
ing upon  the  situation  of  the  territory  of  operation  and  somewhat 
upon  the  natural  tact  of  the  individual,  so  that  a  definition  of 
them  is  scarcely  required.  Upon  a  careful  application  of  the  rests 
and  guards  depends  the  graceful  and  comfortable  use  of  the  instru- 
ments, and  by  means  of  them  the  hand  passes  by  quick  and  easy  grada- 
tion from  the  most  delicate  touch  to  the  safe  exhibition  of  considerable 
force.  Each  student  should  study  and  practice  the  use  of  the  various 
rests  and  guards  until  by  repetition  their  employment  becomes  invol- 
untary and  appropriate  to  the  situation.^ 

The  contact  with  the  patient  should  be  at  as  few  points  as  possible 
and  should  be  generally  made  with  the  fingers. 

Examination  of  the  teeth  and  mouth  in  all  their  particulars  is  a 

^  To  aid  in  tliis  study  see  American  System  of  Dentktry,  vol.  ii.  p.  44  et  seq. 

173 


174  EXAMINATION  OF  TEETH. 

necessary  preliminary  to  the  treatment  of  any  diseased  or  disturbed  condi- 
tion Avliich  may  appear.  The  importance  of  this  procedure  cannot  be 
overestimated,  as  on  it  depends  the  formation  of  a  correct  diagnosis 
of  departures  from  the  normal  state  and  it  becomes  a  basis  for  the 
formulation  of  plans  for  the  treatment  required  to  restore  the  teeth  and 
the  related  structures  to  a  state  of  health,  as  well  as  to  define  the  order 
in  which  the  several  operations  shall  be  taken  up,  since  an  orderly  pre- 
cedence in  the  treatment  of  individual  teeth  is  frequently  necessary. 

It  is  essential  that  the  examination  be  most  thorough,  to  prevent  any 
failure  to  notice  the  least  defect;  since  an  unobserved  slight  lesion  may 
become  a  deeper  injury  in  a  few  months,  and  the  consequences  of  an 
oversight  may  prove  serious. 

Appliances  used  in  Examination. 

The  appliances  required  to  effect  thorough  observation  of  every 
portion  of  each  tooth  to  ascertain  the  extent  of  any  lesion  are  of  several 
kinds,  viz.  mirrors,  magnifying  glasses,  explorers,  floss  silk,  and  wedges. 

The  MIRRORS  should  be  both  plane  and  concave.  The  plane  mirror 
is  important  as  a  means  to  assist  by  the  reflected  image  in  determining 
the  position  of  defects ;  the  concave  as  an  adjunct  to  effect  illumination, 
as  it  concentrates  the  rays  of  light  and  also  may  be  used  to  produce  an 
enlarged  image.  The  enlarged  image,  however,  is  less  sharp  in  defini- 
tion than  the  image  of  the  plane  mirror. 

Working  to  the  Image, — The  plane  mirror  is  an  important  adjunct  in 
all  operative  procedures  connected  with  the  teeth.  Many  situations  in 
the  mouth  do  not  permit  the  direct  reflection  of  the  rays  of  light  to  the 
eye  without  assuming  positions  of  the  body  and  of  the  head  of  the 
operator  which  are  awkward  and  embarrassing  to  free  movement  of  the 
hand,  as  well  as  necessitating  inconvenient  and  tiresome  positions  of  the 
head  of  the  patient.  In  addition,  it  frequently  is  impossible  to  secure 
correct  observation  of  the  progress  of  various  procedures  by  direct 
vision.  These  difficulties  may  be  overcome  by  the  movements  of 
the  hand  being  directed  by  the  image  of  the  field  of  the  pro- 
cedure on  the  mirror.  This  method  of  working  to  the  image  is  at  first 
difficult  to  the  novice,  since  the  images  are  reversed ;  but  by  continued 
effort  it  becomes  as  easy  to  make  correct  application  of  movements  by 
this  method  as  by  the  direct  rays  of  light.  Further  continued  practice 
in  this  way  renders  the  movements  so  completely  under  reflex  control 
that  the  operator  passes  from  a  direct  movement  to  a  reverse  one,  and 
the  contrary,  without  an  apparent  effort  of  the  brain.  This  is  equally 
true  in  all  the  various  movements,  even  of  those  where  the  employment 
of  considerable  force  is  required. 


APPLTANCES   USED  IN  EXAMINATION. 


175 


The   QualUy  of  the  Mirror. — These  appliances  should  constantly  be 
in  good   condition   to  insure  clear  definition  in  the  image.     The  best 
kind  of  glasses  are  those  in  which  the  surface  is  covered  by  a  deposit  of 
jTj^,  YW  pure  silver.     This  furnishes  a  better  reflect- 

ing surface  and  is  more  durable  than  is  the 
so-called  "  silverinsr "  with  tin  and 


mercury. 

Magnifying  lenses  of  about 
four  diameters  are  useful  to  de- 
tect minute  defects  either  in  the 
teeth  or  in  the  condition  of  pre- 
vious operations  upon  the  teeth. 
They  are  used  either  directly  to 
magnify  the  parts,  or  else  to  mag- 
nify the  image  shown  on  the  face 
of  the  plane  mirror  when  direct 
rays  of  light  cannot  be  caught. 
The  latter  method  gives  a  clearer 
definition  than  the  magnified  image 
of  the  concave  mirror. 

The  magnifying  glass  may  be 
the  ordinary  Avatchmaker's  glass 
held  before  the  eye  by  the  muscles 
of  the  brow  and  cheek 
or  the  lens  mounted 
as  shown  in  Fig.  144. 
Such  glasses  are  indis- 
pensable to  the  careful 
practitioner,  since  witli 
their  aid  defects  of  the 
teeth  and  of  operations 
may  be  detected  which 
would  escape  obser- 
vation by  other  means. 

Explorers  are,  es- 
sentially, prolongations 
of  the  fingers ;  they 
convey  impressions  by 
their  vibrations  to  the 


146. 


Fig.  145. 
b ^ 


Self-contained 
socket. 


Magnifying  lens.  ^^iQlV   vibratious  tO  the      Explorer. 

tactile  nerves,  and  are  principally  intended  to  be 
applied  to  parts  where  direct  rays  of  light  cannot  reach.  The  forms 
required  are  simple  and  few.  Their  points  should  be  delicate,  to  enable 
the  smaller  apertures  and  spaces  to  be  entered,  and  are  best  when  made 


17() 


EXAMINATION  OF  TEETH. 


of  piano-wire,  No.  18  B.  &  S.  gauge,  filed  to  acuteness 
and  bent  to  a  shape  similar  to  that  shown  in  Fig.  145. 
This  form  may  be  ap])lied  to  all  surfaces  of  the  teeth, 
and  but  slight  modifications  are  needed  to  explore  posi- 
tions difficult  of  direct  approach.  At  part  a  the  size  of 
the  finer  ones  should  be  No.  25,  and  near  the  ultimate 
point,  h,  No.  30.  The  temper  of  this  kind  of  steel  gives 
sufficient  stiffness  and  also  ])ermits  slight  bending  to  make 
modifications  of  the  form  to  meet  all  requirements.  The 
ultimate  point  may  be  sharpened  and  renewed  at  pleasure. 
The  handles  in  which  these  instruments  are  inserted  may 
be  of  wood,  with  metal  sockets  which  should  be  of  sufficient 
length  to  come  into  contact  with  the  finger ;  or  they  may 
be  fixed  in  metal  holders,  in  which  case  the  latter  should 
be  tapered  to  avoid  weight  and  to  give  balance.  Either 
form  of  handle  should  be  round,  to  permit  fractional 
rotary  change  of  direction.  Fig.  145  shows  an  explorer, 
which  consists  of  a  socket,  into  Avhich  the  wire  point  is 
secured  by  means  of  powdered  shellac  or  powdered  sulfur. 
The  points  may  be  displaced  and  renewed  M'hen  required. 
This  socket  fits  into  the  usual  cone-socket  handles.  Fig, 
146  is  a  self-contained  socket  for  the  same  purpose. 

Explorers  of  this  kind  may  be  re-formed  by  straight- 
ening and  then  re-dressing  between  two  emery-cloth  disks 
in  the  dental  engine,  when  the  points  can  be  shaped  at 
will. 

Floss  silk  is  used  to  pass  between  the  approximal 
surfaces  of  the  teeth  at  the  places  which  are  in  too  close 
contact  to  permit  the  ingress  of  fine  explorers.  In  these 
positions  floss  silk  may  detect  the  presence  of  superficial 
softening  of  the  enamel  by  the  character  of  the  friction 
or  by  the  fraying  of  its  fibers.  It 
also  is  of  use  in  determining  the  con- 
dition of  fillings  on  approximal  faces 
or  the  presence  of  a  deposit  of  sali- 
vary calculus  at  similar  parts.     The 


Dow  electric  lamp  for  mouth  illumination  with  reflectors.   Reflector  A  is  jointed  to  vary  the  angle 
of  reflection.  Reflector  B  is  for  illumination  of  the  fauces.  Reflector  Cls  for  lateral  illumination. 


THE  EXAMINATION.  177 

silk  should  be  slightly  waxed  in  order  to  bind  the  fibers.  Entire 
reliance  cannot  be  placed  upon  the  use  of  silk,  since  it  may  in  some 
cases  pass  slightly  carious  spots  without  the  fibers  being  displaced,  but 
it  frequently  furnishes  indications  for  further  procedures  by  which  to 
estabhsh  certainty  as  to  the  state  of  approximal  surfaces. 

AVedges  are  used  when  neither  explorers  nor  silk  give  positive  indi- 
cations of  carious  action  but  have  raised  doubts  of  the  integrity  of  any 
part.  They  may  be  of  wood  Avhere  the  teeth  are  not  firmly  fixed,  when 
the  space  may  be  immediately  made ;  otherwise,  where  the  fixation  is 
firm,  india-rubber  or  linen  tape  may  be  forced  in. 

Tvansilhnnination  of  the  teeth  and  of  the  adjacent  parts  by  the  elec- 
tric mouth  lamp  (Fig.  147)  is  extremely  useful  in  cases  where  a  question 
has  arisen  as  to  the  condition  of  any  approximal  surface.  Superficial 
changes  of  the  enamel  may  frequently  be  detected  by  this  means.  It 
is  also  of  service  in  diagnosis  of  derangements  of  the  antrum  and  to 
test  the  vitality  of  the  pulp. 

The  Examination. 

The  parts  of  the  teeth  most  liable  to  carious  action  are  those 
which  most  easily  retain  deposits  of  sedimentary  matter  composed  of 
food  debris,  thickened  mucus,  and  bacterial  growths.  These  are  the 
labial  and  buccal  surfaces,  where  the  mechanical  relations  of  the  lips 
and  cheeks  tend  to  retain  sediment ;  the  sulci,  which  by  the  direct 
force  of  mastication  have  food  driven  into  them  ;  and  the  approx- 
imal surfaces.  The  latter  are  the  most  important  to  consider. 
The  interproximal  space  is  a  serious  predisposing  cause  of  caries,  be- 
cause the  counteraction  of  the  tongue  and  cheek  in  adapting  the  food 
between  the  occlusal  surfaces  of  the  teeth  forces  the  finer  particles  of 
the  food  into  the  interproximal  spaces,  where  it  is  retained  by  capillary 
attraction  and  by  the  apposition  of  the  cheeks  with  the  buccal  surfaces 
of  the  teeth.  This  space  is  usually  triangular,  the  gum  forming  the 
base  of  the  triangle.  The  point  where  caries  usually  begins  is  at  the 
apex  of  this  triangle,  where  there  is  the  least  movement  and  inter- 
change of  the  contents  of  the  space,  as  here  the  capillary  force  is  the 
greatest,  so  that  the  fermentative  processes  of  food  decomposition  are 
least  interfered  with. 

The  technique  of  examination  is  as  follows :  After  a  cursory  in- 
spection of  the  denture  witli  the  mirror,  the  explorer  is  applied  to  the 
previously  indicated  surfaces,  particular  care  being  used  in  determining 
the  condition  of  approximal  surfaces,  by  introducing  the  instrument 
into  the  triangular  space,  the  ]ioint  being  directed  toward  the  acute 
angle.  It  should  be  drawn  back  and  forth  with  a  slight  rotary  move- 
ment so  as  to  impinge  the  point  successively  upon  the  whole  a})proxi- 

12 


178  EXAMINATION  OF  TEETH. 

mal  surface  of  cacli  tootli.  Tliis  movement  should  be  made  from  the 
inner  as  well  as  from  the  outer  aspect.  In  this  manner  the  instrument 
will  be  brought  into  contact  with  every  accessible  portion  of  the  inter- 
proximal surfaces. 

Then  the  sulci  are  explored  and  thi;  haccal  (ind  Unf/ual  surfaces 
examined. 

The  inspection  is  thus  conducted  from  tooth  to  tooth.  Next  the  lines 
of  apjxirent  contact  are  critically  tested  with  the  mirror  for  evidence  of 
slow  changes  of  structure  as  shown  l)y  discoloration  or  rapid  alterations 
shown  by  a  milk-like  appearance  of  the  tooth  surface. 

Finally,  all  approximal  surfaces  which  could  not  be  explored  are 
silked.  To  do  this  the  floss  is  wrapped  upon  the  index  finger  of  the 
left  hand,  and  with  the  right  is  drawn  between  the  contact  surfaces 
Avith  a  sliding  lateral  movement.  Care  should  be  exercised  that  no 
injury  be  done  to  the  gingival  margin  of  the  interproximal  space  by 
suddenly  and  forcibly  driving  the  floss  into  contact  with  it.  This  acci- 
dent may  be  effectually  avoided  by  a  proper  guarding  and  supporting 
of  the  fingers  by  contact  with  the  adjacent  teeth.  Practice  gives 
facility  in  determining  by  means  of  the  silk  the  state  of  the  parts  in 
contact  with  it. 

In  the  inspection  of  previous  stoppings,  all  margins,  particularly 
those  beneath  the  gum,   should  be  critically  inspected. 

Lastly,  doubtful  situations  should  be  noted  for  subsequent  examina- 
tion to  be  made  after  separation. 

(The  tests  for  pulp  exposures  are  considered  in  Chapters  VII.  and 
YIII.) 

The  order  of  examination  is  best  conducted  by  beginning  at  the 
median  line  of  each  quarter  of  the  denture,  progressing  posteriorly  with 
one  line  of  observation  and  returning  to  the  place  of  beginning  with 
another  line  of  observation. 

The  Chart  Record. — The  chart  record  should  at  the  same  time  be 
carried  on  by  the  principal,  or  better  an  assistant,  with  the  view  of 
securing  a  complete  record  of  each  derangement,  for  guidance  and  for 
reference.  The  details  of  the  record  are  indicated  in  a  simple  manner 
by  symbols  which  are  illustrated  by  Fig,  148,  and  explained  by  the  glos- 
sary. These  symbols  may  be  combined,  where  required,  to  give  fuller 
expression. 

From  this  temporary  record  im])ortant  operations  when  executed 
may  be  transferred  to  a  permanent  record. 

The  constitutional  condition  and  the  texture  and  apparent  resistance 
of  the  teeth  to  caries  and  attrition  ;  the  inherited  tendency  to  diseases  of 
the  teeth  ;  the  chemical  reaction  of  the  mucous  and  salivary  secretions ;  the 
state  of  the  general  heath  ;  the  condition  of  the  mucous  membrane  of  the 


THE  CHART  RECORD. 


179 


mouth  and  throat ;  the  indications  presented  by  the  tongue  ;  the  dietary 
habits  and  other  hygienic  relations  ;  the  tendency  to  catarrhal  aiFections  ; 
the  presence  of  the  rheumatic  or  gouty  diathesis — are  all  questions  which 


Fig.  148. 


S-EX 


signifies :  In  the  interproximal  space.  c  signifies 

/  "  Attention— re-examine.  ex 

//  "  Superficial  softening.  ~l       " 

///  "  A  carious  cavity.  3 

•  "  At  the  cervix.  3       " 

s  "  To  separate.  D       " 

p  "  To  polish. 


Salivary  calculus. 

To  examine. 

A  pulp  nearly  exposed. 

A  pulp  probably  exposed. 

A  pulp  fully  exposed. 

A  devitalized  pulp. 


enter  into  the  prognosis  and  frequently  largely  determine  not  only  the 
hygienic  directions  to  be  given  to  the  patient,  but  also  determine,  in 
connection  with  the  age  and  habits,  the  important  question  as  to  whether 
the  restorative  operations  shall  be  of  a  permanent  character  or  only  of  a 
temporary  nature  designed  to  preserve  the  teeth  until  restored  normal 
functions  may  make  it  judicious  to  perform  more  enduring  operations. 

The  foregoing  considerations  with  respect  to  the  examination  of  the 
mouth  and  teeth  sufficiently  meet  the  requirements  for  beginning  the 
rational  treatment  of  dental  disorders. 


CHAPTER  VI. 

PRELIMINARY  PREPARATION  OF  THE  TEETH— REMOVAL  OF 
DEPOSITS  AND  CLEANING  OF  THE  TEETH— WEDGING— 
OTHER  METHODS  OF  SECURING  SEPARATIONS— EXPOS- 
URE OF  CERVICAL  INIARGINS  BY  SLOW  PRESSURE,  ETC. 

By  Louis  Jack,  D.  D.  S. 


Cleansing  the  Teeth. 

Before  restorative  operations  are  commenced  upon  the  teeth  all 
deposits  of  salivary  calculus  upon  them  should  be  removed  and  they 
should  be  cleansed  of  the  covering  of  partially  inspissated  mucus 
which  even  in  persons  of  more  than  ordinary  carefulness  is  liable  to  be 
found  upon  them.  This  film  favors  the  admixture  with  it  of  sedi- 
mentary matter  from  food  substances  and  frequently  has  so  much  con- 
sistence as  to  oifer  considerable  resistance  to  its  removal,  and  it  pre- 
vents to  a  degree  the  contact  of  the  naked  brush  with  the  teeth.  Its 
presence  is  in  every  way  detrimental  to  the  preservation  of  the  teeth, 
since  it  not  only  favors  the  adhesion  of  starchy  matters,  but  also  fur- 
nishes, wherever  situated  in  connection  with  these  food  products,  a 
favorable  habitat  for  the  development  of  bacterial  forms  responsible 
for  the  formation  of  the  acid  products  that  are  the  active  agents  of 
enamel  solution.  This  deposit  is  most  frequently  formed  on  the  inner 
and  outer  surfaces  of  the  posterior  teeth,  where  it  invades  the  inter- 
spaces and  in  some  cases  covers  all  surfaces  which  are  not  directly  sub- 
ject to  the  friction  of  mastication.  It  should  be  thoroughly  removed 
and  all  surfaces  should  then  be  carefully  polished. 

The  best  means  to  effect  this  is  to  polish  the  ])arts  with  a  mixture 
of  pulverized  puiaiee  icith  gJycenn.  The  glycerin  binds  the  particles  of 
pumice  and  permits  its  retention  upon  the  polishing  instruments.  The 
persistence  of  the  deposit  is  shown  by  the  fact  that  when  the  pumice 
is  applied  it  is  a  moment  before  the  polishing  implement  comes  into 
actual  contact  with  the  enamel.  To  be  suitable  for  this  jnirpose  the 
pulverized  pumice  should  have  been  elutriated  or  passed  through  a  fine 
bolting  cloth  to  remove  the  coarse  and  irregular  particles  which  if  per- 
mitted to  remain  might  cause  injury  to  the  enamel  surface.  After  the 
removal  a  vitreous  surface  should  be  given  by  quick  friction  with  stan- 

181 


182 


PRELIMINARY  PREPARATION  OF  THE  TEETH. 


Fig.  149. 


nic  oxid  ("  tutty  powder"),  wliicli  also  is  better  applied  when  coml)inod 
Avitli  glycerin  or  rubbed  np  with  vasolin. 

Salivary  calculus  is  found  precipitated  at  parts  not  subject  to  free 
friction,  such  as  the  buccal  surfaces  of  the  molars,  the  inner  faces  of 
the  lower  incisors,  and  it  frequently  invades  the  interstices.     These 

deposits  also  should  be  displaced  and  the 
surfaces  polished. 

The  better  appliances  for  the  removal 
of  superficial  calculus  are  sickle-shaped 
scalers  of  various  sizes  and  forms,  which 
are  inserted  beneath  the  free  margin  of 
the  gum,  when  the  direction  of  the  move- 
ment should  be  obliquely  toward  the 
occlusal  aspect  to  avoid  injury  to  the 
gingival  attachment  with  the  tooth.  The 
consideration  of  the  removal  of  deeply 
seated  salivary  calculus  where  some 
serious  injury  has  been  caused  by  its  presence  is  treated  of  in  Chap. 
XIX. 

Polishing-  the  Triangular  Portion  of  the  Interproximal  Spaces. 
— When  this  is  required  an  efficient  means  is  to  employ  gilling  twine 
of  sizes  proportioned  to  the  space.  This  is  applied  by  looping  one 
or  more  strands  with  a  piece  of  floss  silk,  when  the  silk  is  drawn  up- 
ward into  the  triangle  and  then  is  used  to  pull  the  twine  into  the 
space,  which  being  armed  with  suitable  powders  is  drawn  to  and  fro 
until  the  absence  of  friction  indicates  that  the  surfaces  have  become 
smooth. 


Abbott's  scalers. 


CAEE    BY    THE    PATIENT. 

Coincident  with  the  preparation  above  described  the  patient  should 
be  given  such  instruction  as  will  tend  to  maintain  the  state  of  cleanli- 
ness. The  importance  of  this  should  be  impressed  as  a  necessary 
hygienic  measure  to  preserve  the  teeth.  This  is  to  be  accomplished  by 
the  use  of  suitable  brushes  and  properly  compounded  powders.  The 
detergent  effect  of  powder  is  principally  due  to  the  particles  becoming 
mixed  with  the  film  of  mucus.  This  action  breaks  up  the  continuity 
of  the  film,  which,  with  the  accompanying  sediments,  is  displaced  by 
the  friction  of  the  brush. 

The  correct  use  of  the  brush  requires  that  it  be  placed  with  some 
degree  of  firmness  upon  the  outer  and  inner  faces  of  the  teeth  and  then 
slightly  rotated.  The  pressure  drives  the  bristles  into  the  valleys,  and 
the  rotary  movement  being  away  from  the  gum  avoids  injury  to  that 
structure.     The  application  of  this  procedure  in  combination  with  the 


TREATMENT  OF  THE  MUCOVS  SURFACES.  183 

use  of  2)ichs  and  flosa  silk  should  niaiutaiu  a  correct  hygienic  condition 
of  the  teeth,  upon  which,  in  the  light  of  the  present  knowledge  of  the 
causes  of  solution  of  the  enamel,  depends  the  preservation  of  the  teeth 
from  that  source  of  injury.  It  has  been  shown  that  when  sound 
enamel  becomes  attacked,  the  potent  cause  is  the  fermentation  of 
starchy  deposits  permitted  to  remain  in  contact  Avith  it. 

It  should  be  understood  that  the  use  of  the  pick  removes  deposits 
from  the  cervical  triangle,  and  that  silk  is  intended  to  sweep  the  more 
contracted  portion  of  the  interstice. 

Further  reason  for  care  is  found  in  the  fact  that  the  month  in  an 
unclean  condition  becomes  a  favorable  habitat  for  the  development  of  germs 
some  of  which  may  have  pathogenic  properties  capable  of  aifecting  the 
general  health.  It  therefore  becomes  the  duty  of  the  dental  adviser  to 
enforce  correct  hygienic  conditions  of  the  mouth. 

Much  importance  in  this  connection  should  be  attached  to  the  use  of 
cleansing  preparations  having  inhibitive  action  toward  bacterial  life. 
Those  most  serviceable  contain  hydronaphthol,  which  has  considerable 
efficiency  without  toxicity.  Formalin  as  an  ingredient  of  a  wash  is  also 
applicable,  but  must  be  prescribed  with  considerable  caution. 

Treatment  of  the  Mucous  Surfaces. 

AVhen  the  gums,  the  membrane  of  the  mouth  or  of  the  throat  are 
inflamed,  treatment  preparatory  to  operations  upon  the  teeth  should  be 
directed  toward  restoring  these  parts  to  a  normal  state.  Where  the 
inflammatory  condition  is  not  expressive  of  derangement  of  the  alimen- 
tary functions  and  is  the  result  of  some  simple  local  irritation,  the 
condition  will  usually  respond  to  the  topical  action  of  stimulant  tonics. 

It  is  necessary  here  to  discriminate  as  to  whether  or  not  the  inflamed 
surface  has  been  produced  by  neglected  care  of  the  mouth,  which  fre- 
quently induces  a  lax  condition  of  the  gum  from  the  absence  of  friction 
or  by  the  presence  of  bacteria.  These  may  cause  a  deficiency  of  tone 
or  disorders  in  other  portions  of  the  mouth  and  of  the  throat.  Should 
these  conditions  be  present  the  employment  of  disinfectant  gargles  and 
mouth-washes  is  indicated. 

The  presence  of  salivary  calculus  may  also  induce  inflammatory  dis- 
turbance of  the  gums,  and  from  the  points  of  deposit  this  may  extend 
by  diffusion  over  a  considerable  area.  In  this  connection  deposits, 
either  of  calculus  or  of  sedimentary  accumulations,  posterior  to  the  lower 
third  molars  may  induce  serious  diffuse  inflammation  of  the  contigu- 
ous tissues,  sometimes  extending  to  the  fauces.  For  this  condition  the 
mechanical  removal  of  the  deposits  combined  with  an  antiseptic  spray 
will  usually  be  restorative. 

For  diffuse  redness  and  deficient  tone  of  the  mucous  surfaces  a  wash 


184  PRELIMINARY  PREPARATION  OF  THE  TEETH. 

composed  of  potassium  chlorate  and  quinin  will  j)r()vc  sufficient  in  most 
cases,  as  follows  : 

1^'.  Potassii  chloras,  Sij  ; 

Quininje  sulphas,  gr.  iij  ; 

S[).  rectificatus,  §j  ; 

Aquae,  3vj. — M. 

S.    For  use  as   a  jjargle.  A  dessertspoonful  to  a  winej^lass  of 

water,  or  directly  upon  the  gum  in  full  strength  by  means  of 
a  soft  tooth-brush. 

Concurrently  with  the  local  tlicrapeusis  the  employment  of  massage 
of  the  gum  with  the  tinger,  either  naked  or  covered  with  a  na|)kin,  is 
of  considerable  value. 

When  the  conditions  are  catarrhal  or  are  expressive  of  gastric 
derangement  only  general  treatment  \vitli  concurrent  attention  to  the 
diet  and  correct  hygienic  relations  will  meet  the  requirements  of  the 
case.  Coincident  with  the  general  treatment  above  indicated,  the 
simpler  operations  upon  occlusal  surfaces  may  be  carried  on. 

In  all  cases  of  initial  treatment  for  children  or  nervous  patients  it 
is  important  to  begin  with  simple  and,  as  nearly  as  may  be,  painless 
operations,  to  accustom  such  patients  to  the  more  or  less  disagreeable 
procedures  and  to  elicit  their  interest  and  co-operation  in  what  is  being 
done  for  their  benefit. 

Cavities  on  Appboximal  Surfaces. 

The  preliminary  treatment  of  this  class  of  cases,  on  account  of  the 
limitation  of  space  and  the  necessity  for  somewhat  indirect  application 
of  the  instruments  and  of  the  requisite  force,  necessitates  the  closest 
attention  to  every  detail.  Upon  the  care  here  taken  depends  the 
comfort,  and  furthermore,  indirectly  in  many  instances,  the  health  of 
the  person. 

The  procedure  of  first  importance  is  to  produce  a  sufficient  enlarge- 
ment of  the  interproximal  space.  In  all  cases,  whether  the  teeth  are  in 
apparent  contact  or  whether  they  may,  from  loss  of  substance  on  the 
approximal  aspect,  present  sufficient  room  for  the  management  of  the 
various  procedures,  spacing  is  equally  necessary.  It  is  done  in  order 
that  when  the  stopping  procedures  shall  have  been  completed  the  natural 
relations  of  the  teeth  Avith  each  other  will  be  restored.  This  relation,  as 
before  indicated,  is  one  of  apparent  contact  near  the  occlusal  surfiice 
with  a  triangular  space  at  the  cervix.  The  mechanical  basis  of  this 
arrangement  is  such  that  the  function  of  comminution  of  food  is  better 
effiicted  if  there  is  no  breach  in  the  continuity  of  the  occlusal  aspect  of 
the  denture. 


SEPARATION  OF  THE  TEETH.  185 

The  consequences  of  breaches  of  continuity,  especially  in  relation  to 
the  posterior  teeth,  are  often  of  serious  import.  Not  only  may  the  food 
be  driven  into  the  space,  to  the  discomfort  of  the  ])atient,  but  serious 
injury  of  the  gum  may  follow,  as  in  many  cases  the  tissue  becomes 
inflamed  by  the  impaction  of  food  in  the  enlarged  interspace,  which  in- 
duces peridental  disturbances  and  may  occasion  the  ultimate  loss  of  the 
aifected  tooth.  It  is  also  not  unimportant  to  consider  that  the  forms  of 
the  teeth  have  an  esthetic  value,  and  that  the  harmony  of  the  features 
forbids  the  mutilation  of  their  natural  forms. 

Separation  of  the  Teeth. 

Separation  of  the  teeth  is  a  procedure  requiring  care  to  avoid  injury 
and  to  render  the  process  comparatively  painless. 

When  the  teeth  are  mobile,  as  in  the  case  of  children,  the  movement 
is  more  easily  and  more  quickly  made  than  when  the  alveolar  walls  are 
compact  and  when  also  the  teeth  are  in  close  proximity.  In  the  former 
case  the  arch  easily  expands  and  permits  the  teeth  to  yield ;  in  the  other 
case  the  resistance  requires  more  force  to  be  used  and  the  application 
of  it  for  a  longer  period.  In  all  instances  the  force  and  the  material 
used  should  be  adapted  to  the  presented  conditions  and  the  movement 
should  be  sustained  until  the  required  space  is  gained,  it  being  dele- 
terious to  make  repeated  attempts  to  separate  the  same  pair  of  teeth. 
When  the  proper  precautions  are  taken  there  is  no  dauger  attending 
the  process  ;  even  the  firmest  structures  of  mature  age  permit  sufficient 
spacing  if  it  be  slowly  and  steadily  done. 

METHODS    OF    MAKING    SEPAEATIONS. 

The  means  by  which  these  are  effected  are  various  and  the  choice  is 
determined  by  the  amount  of  space  required,  the  time  in  which  it  must 
be  accomplished,  and  the  firmness  of  the  supporting  structures.  Some 
regard  must  also  be  had  for  the  peculiar  susceptibilities  of  the  patient 
to  the  pain  which  may  be  caused  by  the  effort.  These  methods  are — 
by  immediate  wedging,  which  may  be  made  when  the  fixation  of  the 
teeth  is  not  firm  ;  by  the  swelling  of  firmly  impacted  pellets  of  cotton 
or  of  tape,  and  by  the  resilience  of  strips  of  caoutchouc  where  the  teeth 
are  in  general  contact  and  where  they  are  firmly  fixed. 

Immediate  -wedging-  is  more  applicable  to  the  front  teeth,  where 
usually  only  a  small  space  is  required,  and  is  a  valuable  method  of 
securing  a  separation  of  the  front  teeth  to  determine  their  condition 
and  to  permit  polishing  strips  to  be  inserted  for  the  removal  of  super- 
ficial discolorations  and  for  the  treatment  of  superficial  softening.  Here 
the  ])rocedure  is  to  insert  a  wooden  wedge  between  the  incisors  near  the 
incisive  edge,  when  it  is  forced  by  pressure  or  by  percussion  until  a  suf- 


186 


PRELIMINAnr  PREPARATION  OF  THE  TEETH. 


iiciciit  ()])('nino;  is  eifbctod,  the  sjiacc  llicii  Ucing  secured  hy  anotlier  wedo;e 
of  luinl  close-jrniiiu'd  wood  forced  Ix'tween  the  teetli  at  tlie  cervix.  This 
process  in  some  instances  is  repeated  l)v  forciii«;  fartlier  the  first  wedge 
and  again  increasing  the  security  by  (h-i\'iiig  the  cervical  wedge.  Tliin 
plan  is  not  apjilicahle  when  the  inters])a(!e  at  the  neck  is  quite  angular, 
since  the  fixing  w'cdgc  cannot  be  made  secure,  as  it  then  is  disposed 
to  advance  against  the  gum.  In  this  case  one  of  the  subsequent 
methods  should  be  pursued. 

If  the  fixation  of  the  teeth  be  not  firm  they  yield  by  a  slight  enlarge- 
ment of  the  arch  and  by  closing  the  neighboring  slight  sjxices. 

Immediate  separations  may  be  effected  by  mecJianical  separators, 
notablv  the  William  A.  A\'oodward  (see  Fig.  150),  for  the  front  teeth  and 


Fig.  150. 


Fig.  151. 


Woodward's  separator. 


Perry's  separator  in  conjoint  use  with  matrix. 


the  Perry  (see  Fig,  151)  for  the  bicuspids  and  molars.  It  should  be 
stated  that  each  of  these  is  preferably  to  be  used  when  some  previous 
space  has  been  made  by  other  means,  following  which  a  considerable 
increase  of  space  may  be  secured  by  these  appliances. 

Separation  by  the  Swelling-  of  Fibrous  Materials. — These  act  by 
the  capillary  force  of  water  upon  the  fil)rous  structure  of  the  material, 
whether  pledgets  of  cotton  or  tape.  This  means  is  also  more  applica- 
ble when  the  fixation  of  the  teeth  is  not  firm,  and  has  the  advantage  of 
being  painless  and  more  readily  tolerated  by  children  and  by  persons 
Avho  are  impatient  of  pain  or  of  any  form  of  dental  distress. 

Pledgets  of  cotton  are  more  applicable  where  a  partial  preliminary 
opening  of  a  carious  cavity  has  been  made,  and  are  more  appropriate  for 
the  posterior  teeth.  Here,  when  there  is  no  danger  of  pulp  exposure, 
the  pledgets  may  be  packed  with  considerable  firmness.  In  some 
instances  it  is  advantageous  to  saturate  the  pledget  with  thin  sandarac 
varnish,  which  attaches  the  fibers,  but  the  time  required  is  much  in- 
creased, as  the  cotton  yields  to  capillary  attraction  only  as  it  loses  the 
resin. 

Tape  is  more  useful  for  the  incisors  ;  it  should  l)e  of  linen  and  may 
or  may  not  be  waxed.  Its  entrance  is  facilitated  by  an  immediate  pre- 
liminary application  of  a  wooden  wedge. 


SEPARATION  OF  THE  TEETH.  187 

Caoutchouc — India-rubber. — When  a  strip  of  india-rubber  is 
drawn  into  a  close  interspace  the  middle  portion  is  constricted  to  g-reat 
tenuity.  The  action  is  by  the  resilience  determining  the  Im^o  exposed 
ends  toward  the  middle,  Avith  the  result  that  at  length  the  space  attains 
the  size  of  the  thickness  of  the  strip.  It  will  be  perceived  that  the 
physical  force  is  that  of  two  opposed  wedges  acting  with  constant 
power.  The  effect  is  such  that  it  overcomes  the  greatest  resistance  to 
separation  of  the  parts  and  therefore  is  the  most  effective  means  which 
we  have. 

Caution  is  required  in  the  use  of  this  material  both  as  to  the  thick- 
ness of  the  rubber  and  as  to  its  purity.  The  pronounced  resilience  of 
pure  rubber  is  generally  painful,  and  in  most  instances  greatly  so. 
The  resilience  can  be  reduced  by  employing  adulterated  sjjecimens 
of  the  material.  The  white-rubber  tubing  of  the  shops  cut  longi- 
tudinally into  various  widths  effects  the  object  with  less  rapidity  but 
surely,  and  generally  without  pain.  The  strip  is  drawn  into  position 
by  a  sliding  motion,  care  being  taken  not  to  force  the  piece  into  contact 
with  the  gum.  To  prevent  the  rubber  being  conveyed  to  the  gum  as 
the  space  enlarges,  a  small  portion  should  extend  slightiv  beyond  the 
occlusal  surface.  As  this  kind  of  rubber  is  more  difficult  to  introduce 
when  the  contact  is  close  and  firm,  a  previous  partial  opening  should  be 
made  with  a  piece  of  rubber  dam.  This  method  has  the  value  of  pain- 
lessness, and  also  does  not  usually  necessitate  a  period  of  rest  after  the 
separation  has  been  effected. 

Red  Base-plate  Gutta-percha. — When  it  is  desirable  to  gradually 
effect  considerable  spacing  between  teeth,  where  the  carious  cavities  are 
deep  w'ith  well-defined  boundaries  but  not  involving  the  pulp,  the  method 
of  Dr.  Bonwill,  of  packing  the  cavities  and  the  existing  space  with  a 
sufficient  mass  of  this  form  of  gutta-percha,  produces  expansion  by  the 
continued  force  of  mastication  driving  the  material  upward.  This 
method  also  has  value  in  some  instances  where  it  is  desired  to  force 
the  gum  beyond  the  cervical  margins,  and  may  be  an  acceptable  sub- 
stitute for  aseptic  cotton  for  this  purpose. 

Securement  of  the  Space. — Should  soreness  of  the  teeth  have  been 
caused  by  the  separation,  a  period  of  rest  should  be  given  the  parts  until 
the  distress  has  passed  over.  It  is,  however,  important  that  large  spaces 
should  not  be  long  retained,  since  in  some  instances  alveolar  resorption 
may  be  induced  by  the  continuation  of  the  changed  position.  An  inter- 
val of  two  days  usually  suffices  for  the  pericementum  to  recover  from 
the  disturbance,  when  the  restorative  procedures  may  be  conducted. 

The  retention  of  the  space  may  be  effected  with  gutta-percha  or  -with 
the  plastic  cements, — the  first  being  suitable  when  an  open  cavity 
appears ;  zinc  phosphate  when  from  the  smallness  of  the  cavity  gutta- 


188  PRELIMINARY  PREPARATION  OF  THE  TEETH. 

perchu  nuiy  not  bo  readily  retained.  Oxychlorid  of  zinc  should  be  used 
when  the  cavities  are  shallow  but  sensitive, — the  reason  for  which 
w'ill  appear  later.  It  is  generally  advisable  to  introduce  a  thin  wedge 
of  wood  at  the  cervix  and  in  contact  with  the  gum  to  ])revent  the  re- 
taining material  from  impinging  upon  this  tissue  and  to  give  a  base  to 
su]ij)()rt  the  introducing  force. 

Exposure  of  Cervical  Margins. — When  cavities  extend  beneath 
the  gum,  which  frequently  is  the  case  when  caries  has  recurred  above 
the  cervncal  margins  of  fillings,  it  becomes  necessary  to  force  the  gum 
somewhat  above  the  carious  border.  This  should  be  done  quickly 
ratlier  than  slowly,  otherwise  in  adult  subjects  the  continued  pressure 
may  arouse  diffused  inflammatory  disturbance  of  the  contiguous  tissues. 
Generally  it  is  preferable  first  to  cut  away  the  gum  between  the  teeth 
with  a  straight,  narrow  bistoury,  and  gently  force  red  gutta-percha 
against  the  gum,  gradually  moulding  it  to  the  form  of  the  depression. 
Cotton  pellets  for  this  purpose  are  not  admissible  unless  they  are  auti- 
septically  charged,  for  which  purpose  an  admixture  of  aristol  with  the 
cotton  is  the  most  suitable,  since  not  being  soluble  in  water  it  better 
maintains  the  asepsis.  Cotton  may  be  conveniently  charged  with  aris- 
tol by  saturating  it  with  a  solution  of  aristol  in  chloroform  and  allow- 
ing the  greater  portion  of  the  solvent  to  evaporate  before  introducing 
the  pledget. 

When  hypersensitiveness  of  the  gum  tissues  exists  it  is  admissible  to 
paralyze  the  sensation  with  a  suitable  solution  of  cocain,  previous  to 
introducing  the  pellet  of  either  gutta-percha  or  cotton  fiber.  A  four 
per  cent,  solution  of  cocain  hydrochlorid  applied  upon  cotton  to  the 
sensitive  tissues  will  speedily  relieve  the  condition. 


CHAPTER    VII. 

PRELIMINARY  PREPARATION  OF  CAVITIES— TREATMENT 
OF  HYPERSENSITIVE  DENTIN  BY  SEDATIVES,  OBTUND- 
ENTS, LOCAL  AND  GENERAL  ANESTHETICS— STERILIZA- 
TION, WITH  A  BRIEF  CONSIDERATION  OF  THE  PHYSIO- 
LOGICAL AND  THERAPEUTIC  ACTION  OF  THE  MEDICA- 
MENTS  USED. 

By  Louis  Jack,  D.  D.  S. 


Hypersensitive  Dentin. 

Dentinal  hypersensitiveness  frequently  presents  the  most  serious 
impediment  to  the  procedures  connected  with  the  treatment  of  dental 
caries.  This  condition  must  be  considered  an  exaltation  of  the  normal 
sensitiveness  of  the  dentin,  and  presents  a  wide  range  from  slight  pain 
on  contact  being  made  to  so  high  a  degree  of  sensitiveness  as  to  be  un- 
endurable. In  the  latter  instance  persons  of  the  greatest  capacity  for 
tolerating  pain  will  shrink  from  the  most  careful  instrumentation.  Im- 
mediately upon  the  opening  of  a  carious  cavity  there  usually  are  indica- 
tions of  excitement  of  the  vital  elements  of  the  dentin.  This  con- 
dition may  be  so  slight  as  to  present  no  obstacle  to  furtlier  procedures, 
or  it  may  on  the  other  hand  be  so  excessive  as  to  forbid  all  instru- 
mentation until  a  reduction  of  the  sensitiveness  has  been  effected. 

This  altered  state  of  the  dentin  has  been  considered  by  some  as  one 
of  inflammation  of  the  dentin.  As  the  opportunity  does  not  exist  for 
the  usual  concomitants  of  inflammation  as  pathologically  defined  and 
whieli  arc  induced  by  the  alterations  of  the  circulation  of  the  blood, 
viz.  heat,  redness  and  swelling,  with  exaltation  of  nervous  function 
caused  by  the  additional  supjily  of  arterial  blood,  the  term  inflamma- 
tion is  a  questionable  one  to  apply  to  a  hyperesthetic  condition  of 
dentin.  This  manifestation  is  more  logically  explainable  as  a  disturb- 
ance caused  by  changed  relations  of  a  tissue  which  is  naturally  pro- 
tected by  the  enamel  from  irritating  influences.  The  relation  of  the 
enamel  and  the  dentin  is  analogous  to  that  of  the  epidermal  coat  of 
the  skin  and  the  rete  mucosum.  Pain  caused  by  abrasion  of  the 
epidermis  is  immediate  and  acute,  and  occurs  l)efore  th(>  increased 
supply  of  blood  increases  the  intensity  of  it.     It  is  hence  induced  by 

189 


190  PRELIMINARY  PREPARATION  OF  CAVITIES,  ETC. 

the  altered  relation  of  tlie  mucosiim.  The  analogy  is  further  borne  out 
by  the  fact  that  in  each  instance  a  })rotcctive  covcrino-  affords  salu- 
tary relief. 

The  normal  scnsitiyity  of  dentin  is  not  high,  as  is  shown  by  an 
immediate  examination  of  a  surface  exposed  l)y  accident,  but  after  a 
fe^v  days  the;  denuded  surface  manifests  impatience  of  mechanical 
contact  and  of  applications  of  cold,  which  pi'oyes  that  the  altered  rela- 
tions induce  a  condition  of  the  part  similar  to  the  condition  of  the 
skin  when  the  epidermis  is  broken.  This  appears  to  be  the  case  in- 
dependent of  the  influence  of  chemical  agencies,  as  exaltation  of  sensi- 
tiveness occurs  when  the  fluids  of  the  mouth  are  in  a  normal  state. 
The  same  indications  are  presented  when  a  non-sensitive  cavity  is  pre- 
pared, as  here,  in  case  the  cavity  be  not  protected  by  a  stopping,  the 
same  phenomenon  subsequently  appears. 

Generally  also,  in  such  cases,  if  a  stopping  is  inserted  without  pre- 
viously effecting  a  coagulation  of  the  surfac(>  of  the  cavity,  pain  arises 
upon  reduction  of  temperature.  This  condition  is  designated  as  sec- 
ondary sensitivity,  which  is  caused  by  the  traumatism.  In  some  cases 
of  this  kind  the  pain  becomes  so  great  as  to  require  the  removal  of  the 
stopping  and  the  carbolization  of  the  cavity.  In  extreme  cases  reflected 
pain  in  the  other  teeth  may  appear  in  consequence  of  the  disturbed 
relations  making  an  impression  upon  the  nervous  elements  of  the  pulp. 

When  exposure  of  the  dentin  has  been  brought  about  by  ccaies,  the 
sensitivity  excited  is  liable  to  be  much  exalted  above  the  normal,  and  is 
only  prevented  from  giving  constant  indications  of  this  condition  by 
the  presence  of  the  carious  matter,  which,  being  a  poor  conductor  of 
heat,  in  a  measure  protects  the  pulp  from  thermal  irritation.  This 
accounts  for  the  fact  that  while  there  may  sometimes  be  acute  pain  in 
the  early  stages  of  decay  of  dentin,  the  irritability  and  reaction  of  the 
pulp  appear  to  become  less  as  the  caries  adyances. 

When  the  teeth  are  undergoing  rapid  decay  the  dentin  is  more  sen- 
sitive than  when  the  carious  process  is  slow.  As  the  color  of  the 
carious  matter  gives  some  indication  of  the  rate  of  progress,  we  may 
from  this  indication  form  an  impression  of  the  probable  degree  of 
sensitiveness.  When  the  carious  matter  is  light,  the  action  has  been 
rapid ;  when  it  is  yellow  or  light  brown  it  is  less  active  ;  and  when  it 
is  dark  brown  or  black,  it  has  progressed  very  slowly.  In  some  cases 
of  the  last  character,  when  the  parts  are  subject  to  friction,  spontaneous 
cessation  of  decay  takes  place.  The  parts  are  then  nearly  devoid  of 
sensitiveness.  The  process  by  which  the  dentinal  tubuli  become  oblit- 
erated by  calcific  deposits  is  called  ebuDiation.  AVhcn  the  dentin  be- 
comes exposed  by  attrition,  that  tissue  is  not  as  greatly  irritated  as  it  is 
by  the  progress  of  caries,  since  by  reason  of  the  gradual  loss  of  sub- 


HYPERSENSITIVE  DENTIN.  191 

stance  changes  take  place  witliin  the  tubules  by  which  their  capacity  to 
convey  sensation  is  diminished  or  obliterated  as  the  case  may  be. 

]M\e)i  the  gum  recedes,  exposing  the  cementum,  a  very  high  degree  of 
sensitivity  is  often  excited,  which  is  prone  to  decline  by  spontaneous 
changes  of  structure.  There  is  often  here  the  added  influence  of  acid 
conditions  of  the  mucous  secretions  where  they  flow  out  upon  the  teeth 
at. this  point,  and  where,  too,  the  parts  are  not  easily  cleansed.  It  is  a 
notable  fact  in  connection  with  cervical  hypersensitiveness  that  while  it 
persists  these  parts  are  less  liable  to  decay  than  when  loss  of  sensitive- 
ness here  takes  place. 

The  area  of  hypersensitivity  usually  is  not  evenly  distributed 
throughout  the  carious  cavity,  but  has  its  chief  seat  near  the  line  of 
union  of  the  dentin  with  the  enamel,  thus  bearing  out  the  law  that 
sensitivity  is  greatest  at  the  terminal  end-organs  of  the  sensory  nerves, 
with  the  further  qualification  that  the  more  minute  the  fibrillse  the 
greater  may  be  the  acuteness  of  the  sensitivity.  This  fact  is  illus- 
trated by  the  example  of  cavities  in  the  occlusal  surfaces  of  the  molars, 
whicli  manifest  pain  only  at  the  margins ;  is  only  less  evident  in  the 
cavities  of  approximal  surfaces,  and  is  strongly  shown  in  the  shallow 
buccal  and  labial  cavities,  which  present  their  whole  surfaces  near  the 
line  of  juncture  of  enamel  and  dentin. 

In  most  cases  of  caries,  the  zone  of  highest  sensitivity  is  iimaediateli/ 
beneath  the  soft  portion  of  the  decay,  and  when  this  layer  of  dentin  is 
cut  away  the  pain  becomes  less,  in  some  instances  approaching  the  nor- 
mal. This  statement,  howev^er,  has  force  only  in  the  milder  manifesta- 
tions of  this  condition. 

The  Effect  of  Acid  Conditions  of  the  Oral  Fluids. — In  the  pre- 
vious chapter  some  allusion  was  made  to  the  fact  that  an  add  state  of 
the  oral  fluids  is  detrimental  to  the  teeth  as  promoting  carious  action, 
and  that  alkaline  or  even  neutral  states  have  a  retarding  influence. 
Here  it  must  be  considered  as  an  axiom  that  no  cause  is  so  active  as  a 
primary  influence  in  inducing  excessive  dentinal  sensitivity  as  a  con- 
stant slightly  acid  state  of  these  fluids  ;  and,  conversely,  that  a  neutral 
or  slightly  alkaline  state  is  non-irritating.  These  conditions  should  be 
kept  in  constant  view  in  dealing  with  this  subject. 

The  degree  of  sensitivity  of  dentin  is  modified  by  a  variety  of 
other  general  conditions.  These  are — relative  density  of  the  structure, 
rapidity  of  the  carious  action,  and  the  constitutional  peculiarities  of  the 
person  which  are  connected  most  dii-ectly  with  nervous  impressiona- 
bility to  disturbances  of  the  tissues. 

The  rate  of  progress  of  caries  exerts  considerable  modifying  influence 
over  dentinal  sensitivity.  AMien  caries  is  of  slow  progress  the  amount 
of  organic  tissue  exposed  to  irritation  is  comparatively  small,  for  the 


192  PRKLIMINARY  PREPARATION  OF  CAVITIES,   ETC. 

reason  that  the  well-known  salutary  and  protective  changes  of  structure 
go  on  coincidently  with  the  slow  inroad.  The  slight  irritation  of  slowly 
advancing  caries  to  some  extent  exerts  a  stimulating  influence  toward 
inducing  tubular  deposits.  On  the  other  hand,  when  the  carious  pro- 
cess progresses  with  ra})idity,  re])arativc  etforts  upon  the  ]iart  of  the 
pulp  are  paralyzed,  the  organic  elements  of  the  tissue  become  denuded 
to  a  greater  extent,  and  therefore  sensitivity  is  increased  to  a  propor- 
tionate degree. 

As  these  fibrillar  elements  are  the  means  of  extending  the  irritation 
to  the  j)ulp  of  which  they  are  the  peripheral  prolongations,  it  is  evident 
how  important  a  foctor  the  active  advance  of  caries  is,  and  also  to  what 
extent  the  rapidity  of  the  process  increases  the  morbid  concomitants 
of  dental  caries.  It  has  been  pointed  out  that  the  area  of  hypersensi- 
tiveness  generally  pertains  to  a  narrow  line  at  the  outer  limit  of  the 
dentin,  but  in  rapid  caries  this  line  is  a  broader  one. 

The  anatomical  element  of  the  dentin  concerned  with  its  sensi- 
tivity is  contained  within  the  tubuli.  AVhile  the  exact  nature  of  the 
matter  in  these  tubules  has  not  yet  been  certainly  determined,  it  has 
been  shown  to  have  sufficient  consistence  to  permit  of  extension,  as 
in  separating  sections  under  the  microscope  what  apjjcar  to  be  fibers 
have  been  seen.  Also  the  same  appearance  has  been  presented  in  fresh 
specimens  when  the  pulp  has  been  drawn  away  from  the  dentin.  It 
is  not  difficult  in  reviewing  these  facts  in  connection  with  the  various 
conditions  and  phases  of  dentinal  sensitivity  to  conclude  that  the  exalta- 
tion is  inseparably  connected  with  an  irritated  state  of  the  tubular  con- 
tents. The  variation  in  the  degree  of  sensitivity  of  different  teeth  of 
the  same  mouth — of  those  which  are  side  by  side  and  in  a  similar 
degree  of  progress  of  carious  action  ;  the  profound  fact,  heretofore  stated, 
that  the  dentin  at  a  short  distance  beneath  the  decay  is  much  less  sen- 
sitive ;  that  in  some  instances  sedatives  modify  the  degree  of  pain,  and 
that  coagulants  produce  a  marked  impression  upon  the  capacity  of  the 
tubular  contents  to  convey  sensation,  force  by  inference  the  conclusion 
that  in  diseased  conditions  this  anatomical  element  is  largely  concerned 
in  conveying  impressions  to  the  central  organ  of  the  tooth. 

It  is  also  undoubted  that  unusually  high  sensitivity  of  dentin  is  an 
inherent  constitutional  condition  with  some  persons,  and  that  it  pertains 
to  some  families  apparently  as  an  inheritance,  but  may  be  explained  in 
these  instances  as  the  transmission  of  acute  nervous  impressionability. 

In  connection  with  this  subject  should  be  considered  the  further 
observation  that  the  temperature  sense  of  the  teeth  is  various  ;  that  with 
some  the  application  of  ice  makes  no  impression  upon  the  teeth  when 
in  normal  condition,  M'hile  with  others  in  the  same  condition  the  least 
cold  induces  pain.  It  would  further  appear  that  the  degree  of  sensitivity 


TREATMENT  OF  DESTINAL  HYPERSENSITIVITY.  193 

when  caries  occurs  bears  some  relation  to  the  relative  tolerance  of  the 
teeth  to  reduction  of  temperature. 

On  these  premises  it  is  not  difficult  to  account  for  the  manifestation 
of  acute  sensitivity,  and  to  build  thereon  an  hypothesis  governing  the 
various  conditions  presented  by  dentin  when  it  is  subjected  to  the  irri- 
tation of  the  carious  process.  These  views  have  steadily  gained  sup- 
port with  the  advance  of  microscopic  study  of  the  tissues,  and  have 
supplanted  the  older  view  tliat  the  sensitivity  of  dentin  is  a  result  of 
mechanical  vibrations  extending  to  the  dental  pulp. 

Treatment  of   Hypersensitivity  of  the  Dentin. 

Having  considered  the  general  principles  governing  h}^ersensitivity 
of  dentin,  we  are  prepared  to  enter  upon  a  study  of  the  treatment. 
This  is  to  be  considered  under  the  following  general  lines  :  namely, 
the  therapeutic,  the  chemical,  the  anesthetic,  and  the  mechanical. 

Treatment  of  Slight  Hypersensitivity. — The  first  requisites  to  be 
observed  here  are  a  calm  manner  and  earnest  sympathy,  accompanied 
with  the  assurance  that  if  severity  of  pain  occurs,  mitigating  means  will 
be  resorted  to.  It  is  an  important  and  laudable  object  to  remove  dread 
and  secure  confidence,  which  is  attained  among  other  means  by  select- 
ing at  first  the  simpler  and  less  painful  operations.  When  confidence 
is  secured,  slight  pain  arouses  the  courage  of  the  patient.  The  effect  of 
the  opposite  course  of  indifference  and  harsh  cutting  alarms  the  patient, 
arouses  apprehension,  and  greatly  increases  the  nervous  exaltation. 

In  the  simpler  eases  sharp  instruments  used  with  quick,  light,  and 
rapid  movements  are  called  for.  It  should  in  this  connection  be  noted 
that  cutting  in  this  manner  stimulates  somewhat  the  nervous  force  of 
the  patient,  and  if  the  movements  are  in  very  quick  succession  they 
appear  to  paralyze  the  part ;  the  pain  is  thus  lessened  in  comparison 
with  deliberate  and  slow  instrumentation.  The  movements  of  the  ex- 
cavators should  be  in  a  direction  away  from  the  pulp  rather  than  toward 
it,  and  the  cuts  should  be  by  drawing  the  points  instead  of  pushing 
them  :  this  is  for  the  reason  that  the  pressure  in  the  latter  case  is  greater 
than  in  the  former. 

AVhon  the  sensitiveness  is  so  great  as  to  interdict  immediate  excava- 
tion and  formation  of  the  cavity,  some  method  of  treatment  of  the  sur- 
face is  required  to  overcome  or  to  confine  it  witliin  a  tolerable  degree. 

The  Therapeutic  Treatment. — lender  this  head  the  available  reme- 
dies are  morphin,  veratrin,  and  cocain, — each  of  them  being  applied 
with  glycerin  as  a  menstruum.  It  should  be  stated  that  neither  have 
much  immediate  effect,  and  therefore  they  should  be  sealed  in  the  cavity 
after  the  opening  in  the  enamel  has  been  prepared,  and  the  softer  caries 
has  been  lifted    and    peeled  off.     The  closure    should  be    effected    by 

13 


194  PRELIMINARY  PREPARATION  OF  CAVITIES,   ETC. 

means  of  gutta-percha,  or  with  what  is  probably  better,  a  thin  paste  of 
phosphate  of  zinc  laid  over  the  dressing.  After  some  days  the  pain  will 
be  found  diminished  in  many  instances.  The  therapeusis  is  effected  by 
the  absorption  of  these  sedatives  by  the  partially  disorganized  tissues. 
Another  method  of  applying  cocain  is  to  secure  the  cavity  from  the 
entrance  of  moisture,  and  after  desiccating  the  surface  a  saturated 
pledget  of  vapocain,  a  solution  of  cocain  in  sulfuric  ether,  is  introduced. 
As  evaporation  of  the  ether  takes  place  cocain  is  forced  by  osmosis  into 
the  tissue.  In  cases  of  subacute  sensitivity  this  means  frequently  is 
efficacious,  but  is  of  little  value  in  hypersensitive  conditions.  It  is 
advantageous  as  preparatory  to  this  line  of  treatment  first  to  neutralize 
the  acidify  of  the  cavity  Avith  an  alkaline  solution,  which  may  be  either 
ammonia,  sodium  carbonate,  or  sodium  dioxid,  afterward  removing  the 
excess  of  alkali  by  thorough  washing  with  warm  water. 


Treatment  of  Hypersensitivity  of  Dentin  by  Electrical 

Osmosis. 

Within  a  recent  period  a  means  of  treatment  of  this  condition  has 
become    prevalent    which    has    been    designated    by  the    terms    cata- 

PHORESIS,     ELECTRICAL     DIFFUSION,     and     ELECTRICAL    OSMOSIS.         It 

has  been  demonstrated  that  the  action  of  electrical  currents  conveys 
fluids,  with  the  substances  held  in  solution,  from  the  positive  elec- 
trode toward  the  negative  electrode.  Further,  that  an  electrical 
current  ])assing  through  a  membrane  accelerates  the  natural  process 
of  osmotic  diffusion  if  the  positive  pole  is  applied  on  the  side  of  a 
membrane  or  tissue  from  which  the  osmotic  diffusion  is  taking  place ; 
in  case  the  situation  of  the  poles  be  reversed,  the  osmosis  is  retarded  or 
prevented  from  occurrence  or  is  reversed.  This  action  bears  some 
analogy  to  that  which  takes  place  in  electro-metallurgy  when  a  metal 
in  solution  is  conveyed  from  the  anode  (positive  pole),  and  is  deposited 
upon  the  cathode  (negative  pole).  If  the  current  be  reversed  the 
deposited  metal  is  again  taken  up  In'  the  solution  and  is  conveyed 
back  again  to  the  other  pole.  This  is  a  law  connected  with  the 
passage  of  electrical  currents  through  fluids  which  are  capable  of  con- 
duction. 

The  following  will  illustrate  the  action  which  takes  place  :  "  If  two 
compartments  separated  by  a  membrane  arc  filled  with  a  fluid  and  in 
each  an  electrode  is  placed,  there  is  a  streaming  of  the  fluid  through  the 
septum  from  the  positive  to  the  negative  pole,  so  that  in  time  there  is 
an  increase  in  the  negative  side.  This  osmotic  action,  as  is  w'cll  known, 
occurs  naturally  between  two  fluids  of  unequal  density  from  the  lighter 
to  the  denser  liquid,  but  if  the  anode   is  placed  in  the  denser  liquid 


DENTINAL   ANESTHESIA    BY  ELECTRICAL   OSMOSIS.  195 

and  the  cathode  in  the  lighter  the  natural  osmotic  current  is  not  only 
overcome  but  is  reversed." 

If  a  substance  containing  water,  as  a  ball  of  wet  clay  or  a  piece  of 
muscular  tissue,  have  an  anode  connected  with  a  current  of  sufficiently 
high  potential  attached  to  one  side,  with  a  cathode  attached  to  the  oppo- 
site side,  the  watery  contents  of  the  substance  are  conveyed  to  and  appear 
in  excess  on  the  cathodal  side;  at  the  same  time  the  anodal  side  be- 
comes less  damp ;  also,  if  a  capillary  tube  be  filled  with  water  and  an 
anode  and  a  cathode  be  similarly  arranged,  the  water  flows  toward  the 
cathode. 

As  a  membrane  or  tissue  may  be  considered  to  be  a  series  of  tubes 
in  close  contiguity,  it  is  apparent  that  the  movement  of  fluids  must  take 
place  through  them  in  the  direction  the  current  is  passing. 

These  examples  are  an  expression  of  electrical  force.  The  applica- 
tion of  this  law  of  the  passage  of  fluids  from  a  higher  to  a  lower  elec- 
trical potential  is  the  fundamental  process  which  is  employed  in  electrical 
diffusion  of  medicaments.  The  depth  to  which  medicaments  may  be 
conveyed  depends  upon  the  conductivity  of  the  tissue  and  that  of  the 
medicament  which  is  being  ap])lied. 

"  The  cataphoric  action  of  electricity  has  often  been  made  use  of 
experimentally  to  introduce  drugs  into  the  system  through  the  skin. 
In  man  quinin  and  potassium  iodid  have  been  thus  introduced  and 
subsequently  been  detected  in  the  urine." 

As  early  as  1859  Dr.  B.  W.  Richardson  used  this  process  to  pro- 
duce local  anesthesia,  and  completely  demonstrated  its  power  in  this 
direction.  It  has  also  been  clearly  proven  that  when  a  solution  of 
cocain  is  applied  to  the  skin,  its  characteristic  action  upon  the  mucous 
membrane  will  not  here  take  place.  But  when  the  anode  is  wet  with 
the  solution  and  a  galvanic  current  is  passed  through  the  e})idermis 
to  the  cathode,  placed  upon  an  indiflerent  surface,  anesthesia  is  effected 
over  the  surface  covered  by  the  anode  and  to  an  indefinite  distance 
inward. 

This  effect  is  not  |)roduced  by  the  current  alone,  which  has  been 
abundantly  proved  by  conclusive  experiments,  these  having  been  fol- 
lowed by  demonstrations  confirming  the  above  statement.  When  the 
medicaments  so  applied  have  anesthetic  or  analgesic  ])roperties  their 
characteristic  eflPects  are  produced. 

When  this  principle  is  applied  to  the  transfer  of  medicaments  it  is 
found  that  they  pass  for  an  indefinite  distance  into  the  contiguous  tissue 
along  with  the  current  from  the  anc^dc  toward  the  cathode,  but  with 
some  degree  of  diffusion ;  the  diffusion  depending  upon  the  resistance 
of  the  tissue  and  upon  the  extent  of  the  surface  of  the  cathodal  (nega- 
tive) electrode. 


196  PRELIMINARY  PREPARATION  OF  CAVITIES,   ETC. 

GENERAL   PRINCIPLES   INVOLVED    IN    THE   METHOD. 

The  application  of  electricity  requires  the  consideration  of  the 
general  principles  or  laws  governing  its  transmission. 

The  source  of  this  force  is  to  be  found  in  chemical  transformation. 
Under  the  laws  of  the  correlation  of  force  it  is  capable  of  being  con- 
verted into  heat,  light,  magnetism,  and  me(;hanical  power,  and  may  be 
used  to  disorganize  substances,  wlien  its  action  is  called  electrolysis.  Its 
movements  are  constant  in  their  direction,  viz,  from  bodies  of  high  to 
those  of  low  potentiality. 

In  perfectly  conducting  substances  electricity  moves  with  entire  free- 
dom under  any  electro-motive  force  however  small. 

In  perfectly  non-conducting  substances  electricity  will  not  move 
under  any  electro-motive  force  however  great. 

In  imperfectly  conducting  substances  electricity  moves  only  on  the 
exhibition  of  intense  electro-motive  force,  the  force  varying  according 
as  the  substance  is  a  more  or  less  indifferent  conductor. 

Electricity  has  two  elemental  properties.  These  are  defined  as  cur- 
rent strength,  designated  by  the  term  amperage ;  and  electro-motive 
force,  which  is  termed  its  voltage. 

The  active   energy  of  electricity  depends  upon   the   first   property, 
its  distribution   upon  the  latter.     Since  it  must  be  assumed  that  few 
bodies  are  perfect  conductors,  this  force  or  pressure  is  of  that  degree 
which  may  be  required  in  any  given  case  to  move  the  active  energy, 
the  amperage,  against  the  resistance  it  meets  with. 
The  unit  of  strength  is  the  ampere. 
The  unit  of  pressure  is  the  volt. 
The  unit  of  resistance  is  the  ohm. 
The  unit  of  poicer  is  the  watt. 

A  volt  represents  the  electro-motive  force  (E.  M.  F.)  required  to 
impel  one  ampere  of  current  through  one  ohm  of  resistance. 

An  AMPERE  of  current  is  so  much  as  will  deposit  0.00118  gram  of 
silver  per  second  when  passing  through  a  standard  solution  of  nitrate 
of  silver — or  which  will  decompose  0.09326  milligram  of  water  in  one 
second.  Hence  the  ampere  is  the  measure  of  rate  of  flow  of  an  electri- 
cal current,  and  in  connection  with  the  voltage  measures  the  energy  of 
the  current. 

The  unit  of  resistance  (ohm)  is  that  degree  of  resistance  which 
will  permit  the  passage  of  one  ampere  of  current  at  one  volt  of 
pressure. 

The  watt  is  the  power  exerted  by  one  ampere  of  current  at  one  volt 
of  pressure. 

In  the  economic  application  of  electricity  its  transmission  is  effected 


DENTINAL  ANESTHESIA   BY  ELECTRICAL   OSMOSIS.  197 

throngli  metallic  conductors.  The  resistance  of  these  is  varied  by  the 
character  of  the  metal,  the  cross  section,  and  the  distance.  For  certain 
purposes  other  substances  are  employed  to  eifect  greater  resistance  than 
the  metals. 

The  current  strength  flowing  in  a  circuit  is  equal  to  the  pressure 
divided  by  the  resistance. 

The  resistance  equals  the  pressure  divided  by  the  strength. 

The  pressure  equals  the  strength  multiplied  by  the  resistance.  In 
elementary  terms  : 

Amperes  =  volts  ^  ohms. 

Ohms        —  volts  -^  amperes. 

Volts         =  amperes   X  ohms. 

AVatts        =  volts  X  amperes. 

It  follows  from  the  formula  that  the  amount  of  power  and  the  cost 
of  producing  it  is  the  same  whether  the  current  is  of  large  amperage  at 
low  voltao:e  or  of  small  ampera<i::e  at  hiffh  voltao-e.  Thus  an  incandes- 
cent  lamp  may  be  supplied  by  100  volts  at  ^  ampere  or  by  50  volts  at 

1  ampere — the  result  in  each  case  being  50  watts. 

Comparative  Illustration. — Given  a  current  of  100  volts  at  fifteen 
amperes,  and  we  wish  to  use  only  |-  ampere,  the  resistance  to  be  put 
in  the  circuit  is  found  thus  :  100  v  ^2^a  —  40  o. 

In  case  we  have  2^  amperes  under  7  ohms  resistance,  it  requires 
17.V  volts  to  move  this  degree  of  amperage  through  the  given  resistance, 
thus  :  2^  a  X  7  r  =  17|-  v.  If  one  has  a  current  of  110  volts,  and  de- 
sires to  use  a  ^-horse-power  motor,  the  least  amperage  required  is  Iywo) 
which  is  found  by  dividing  186  watts  by  110.  These  examples  make 
plain  the  means  of  determining  the  character  of  current  required  for 
any  given  purpose. 

Electrical  force  may  be  produced  from  its  source  in  galvanic  cells  by 
arranging  them  in  series  or  in  multiple.  If  in  series  the  voltage  is 
the  sum  of  the  volts  of  the  cells  so  arranged,  and  the  amperage  is  that 
of  each  of  the  cells.  If  joined  in  multiple,  the  strength  in  amperes 
is  the  sum  of  the  amperes  of  the  cells,  and  the  voltage  is  that  of  one 
cell. 

Fig.  152^  represents  the  arranging  of  cells  in  series,  the  positive  of 
one  with  the  negative  of  the  next.     In  case  each  cell  has  a  voltage  of 

2  and  an  amperage  of  1  the  electro-motive  force  of  5  cells  will  be  10 
volts  at  1  ampere. 

Fig.  153^  represents  the  joining  of  cells  in  multiple.     Here  all  the 

^See  Dented  Cosmos,  December  1896,  p.  998.  =*  Ibid. 


198 


PRELIMINARY  PREPARATION  OF  CAVITIES,   ETC. 


positive  elements  arc  joined  toi^etlicr  and   similarly  all   the  negative  to 
each  other.     The  voltage  now  is  2  and  the  amperage  5. 


Fig.  152. 


S_ 


+  ■ 


s 


The  former  method  of  assembling  the  cells  is  designated  as  "high 
tension,"  the  latter  method  as  "low  tension."     When  the  source  is  the 


Fig.  153. 


dynamo,  high  and  low  tension  are  produced  by  the  strength  or  weakness 
of  the  magnetic  field. 

For  electrical  osmosis  the  source  should  be  from  batteries  in  series, 
for  the  reason  that  in  multiple  the  amperage  would  be  too  great  when 
the  voltage  is  of  sufficient  force  to  overcome  the  resistance. 

The  degree  of  electrical  energy  tolerated  by  living  dentin  is  exceed- 
ingly small,  on  account  of  the  peculiar  and  intense  pain  excited  by  the 
transmission  of  electrical  currents  through  the  teeth.  This  is  shown  by 
the  low  initial  voltage  of  the  batteries  used  for  the  purpose,  varying 
from  less  than  5  to  rarely  more  than  20.  But  the  initial  passage  of  a 
current  of  as  high  electro-motive  force  as  these  would  not  be  tolerable, 
and  must  therefore  be  reduced  by  suitable  methods  of  effecting  re- 
sistance. 

The  apparatus  used  for  this  purpose  is  the  controller,  the  purpose  of 
which  is  through  its  resistance  to  diminish  the  energy  of  the  current  to 
sufficient  weakness  to  meet  the  requirements  of  any  given  case.  All 
forms  are  constructed  on  the  principle  of  the  use  of  materials  which  are 
highly  resistant  of  the  passage  of  electric  currents.     These  substances 


DENTINAL   ANESTHESIA   BY  ELECTRICAL    OSMOSIS  199 

are  water,  carbon,  graphite,  and  coils  of  wire  of  known  high  resistance, 
the  most  effective  being  of  German  silver.  In  the  case  of  the  latter  the 
degree  of  resistance  is  regulated  by  the  length  and  fineness  of  the  wire, 
the  cross  section  being  reduced  to  the  size  which  will  conduct  the  cur- 
rent without  excessive  heating,  and  to  that  end  it  is  graded  with  refer- 
ence to  the  initial  amperage  of  the  current.  In  comparison  with  silver 
as  a  unit  German  silver  has  a  resistance  of  13.92. 

The  carbon  and  graphite  controllers  usually  are  constructed  in  the 
form  of  a  broken  ring — one  pole  of  the  battery  being  connected  at  one 
end  of  the  ring,  the  other  pole  being  attached  to  an  index  which  travels 
over  this  annular  disk.  This  method  of  construction  gives  a  fine  grada- 
tion of  current  with  high  resistance.  It  may  be  used  in  connection  with  a 
German-silver  wire  rheostat,  where  currents  of  great  strength  are  used 
for  reasons  which  will  appear  later.  In  the  use  of  high-voltage  cur- 
rents, such  as  the  110-volt  circuit,  it  may  be  switched  through  the 
coils  to  a  nearly  definite  low  voltage  by  means  of  a  rlieostat,  when 
the  adaptation  to  the  case  may  be  effected  through  the  graphite  con- 
troller. 

In  the  arrangement  of  the  apparatus  to  effect  electrical  osmosis  the 
battery,  the  controller,  the  instruments  of  observation,  and  the  patient 
are  in  series.  In  the  analysis  of  the  course  of  the  current  it  apjjears  that 
the  patient  is  another  element  of  resistance,  and  that  dentin  is  more 
highly  resistant  than  the  other  tissues.  In  other  words,  there  are  two 
resistances  in  the  circuit — the  controller  and  the  tissues  of  the  patient. 
The  result  of  the  resistance  of  the  dentin,  unless  the  initial  voltage  is 
small  and  is  reduced  by  the  controller  to  an  infinitesimal  degree,  is  the 
occurrence  of  pain,  which  takes  place  with  different  persons  at  various 
degrees  of  amperage.  The  approacli  to  intolerance  of  the  current  is 
designated  the  "  pain  limit."  This  condition  has  been  assumed  by  some 
observers  to  be  caused  by  the  evolution  of  heat  in  the  dentin  con- 
sequent upon  the  resistance  of  this  tissue.  This  view  is  not  now  con- 
sidered to  be  conclusive,  as  the  calculated  elevation  of  temperature  at 
j^  milliampere  is  not  sufficient  to  account  for  the  degree  of  irritation 
which  occurs  on  increasing  the  rate  of  flow.  This  determination 
leaves  two  other  hypotheses  to  account  for  the  irritation  :  ((,  the  ten- 
dency of  the  current  to  disorganize  some  of  the  anatomical  elements  of 
the  canaliculi ;  and  b,  the  osmotic  pressure  of  the  migration  of  the 
medicaments.  Here  the  student  is  not  confused  with  consideration  of 
the  complicated  forces  which  are  in  action  connected  with  the  electroly- 
sis of  the  cocain  solution.^ 

The  pain  limit  is  variable  with  different  ])ersons,  and  in  different 

'  See  "The  Foundation  Principles  of  Dental  C'ataplioresis,"  Items  of  Interest,  vol.  xx. 
\).  345  et  scq. 


200  PRELIMINARY  PREPARATION  OF  CAVITIES,   ETC. 

teeth  of  the  same  jxn-soii.  With  sonio  it  is  reached  Avitli  the  first 
influx  of  the  current  at  low  voltage  with  a  recoi-d  of"  ^'|,  inillianipere, 
this  low  record  indicating  high  resistance  of  dentin  and  ])erinitting  but 
slow  increase  of  the  force  until  after  cocain  has  diminished  the  sensitiv- 
ity of  the  irritated  surface.  AVith  others  the  ])ain  limit  may  not  be 
reached  with  a  voltage  of  20  and  a  recorded  amperage  of  ^V  to  y^,y  milli- 
ampere.  In  respect  of  electrical  irritation  there  must  be  taken  into 
account  also  the  high  nervous  sensitivity  of  some  persons,  as  with  these 
there  usually  appears  greater  susceptibility  to  electrical  irritation. 

The  following  table  of  calculated  resistances  shows  the  resistance 
in  ohms,  and  the  liability  to  the  generation  of  heat  in  the  dental  tissues 
in  view  of  their  density,  or  the  tendency  to  disorganization  as  ])reviously 
stated,  and  it  suggests  that  care  be  used  in  the  application  of  electrical 
force  for  the  purpose  under  consideration. 

Witli  15  volts  initial  pressure  at  x*o  niilliampere  in  circuit  the  olims  are    .S7,500. 
"     15  "  "  J^  "  "  "  150,000. 

"     10  "  "  t1j  "  "  "  25,000. 

"     10  "  "  tV  "  "  "  100,000. 

"       5  "  "  T%  "  "  "  12,500. 

"       5  "  "  tV  "  "  "  50,000. 

As  the  resistance  of  the  body  including  the  dental  tissues  varies  from 
10,000  to  almost  70,000  ohms,  it  would  appear  necessary  that  the  con- 
troller should  have  at  the  highest  ])oint  a  resistance  of  not  less  than 
400,000  ohms.  This  degree  of  resistance  is  required  to  obviate  the 
effect  of  impulse  which  may  occur  in  closing  the  circuit.  Occasionally 
slight  shock  is  felt  at  600,000  ohms. 

The  varying  resistance  of  the  current  through  the  tissues  depends 
upon  the  density  of  the  dentin,  the  distance  traversed,  the  condition 
of  the  surface  of  the  skin,  and  the  thickness  of  the  adipose  tissues. 

The  average  resistance  of  the  patient  as  recorded  by  Dr.  W.  A.  Price 
is  about  25,000  ohms  from  cavity  to  hand,  and  the  difference  of  resistance 
from  tooth  to  hand  and  cheek  to  hand  is  from  3000  to  5000  ohms.  He 
reports  one  case  where  the  resistance  from  cavity  to  hand  with  a  40  per 
cent,  solution  of  cocain  was  28,500  ohms,  which  on  placing  the  pad  on 
the  cheek  was  reduced  to  23,000  ohms. 

Dr.  Price  further  places  the  average  resistance  from  hand  to  tongue 
at  9000  ohms,  and  from  cheek  to  tongue  at  from  3000  to  7000.  This 
w^ould  make  the  resistance  of  the  dentin  nearly  20,000  ohms.  An 
exact  determination  of  the  resistance  of  the  skin  in  any  given  case 
would  enable  a  very  close  approximation  for  the  dentin  to  be  calculated. 

The  condition  of  the  cavity  as  to  relative  moisture  and  the  degree 
of  saturation  of  the  pledget  of  cotton  containing  the  anesthetizing  agent 


DENTINAL  ANESTHESIA   BY  ELECTRICAL   OSMOSIS.  201 

as  well  as  the  percentage  of  the  medicament  exert  a  considerable  quali- 
fying control  of  the  resistance,  as  appears  from  the  experiments  of 
Dr.  Price.  When  a  section  of  dentin  partially  dry  on  the  surface  had 
a  resistance  of  30,000  ohms,  after  being  dried  and  saturated  with  a  40 
per  cent,  solution  of  cocain  the  resistance  was  reduced  to  4500  ohms. 

The  principles  here  stated  and  the  facts  presented  apparently  demon- 
strate the  importance  of  careful  selection  of  the  degree  of  voltage  at 
the  battery  ;  of  the  use  of  a  relatively  low  amperage  to  the  voltage; 
of  the  necessity  of  controlling  the  current  within  the  boundary  of  the 
pain  limit ;  of  the  importance  of  avoiding  impulses  of  current  by  rapid 
advancement  or  by  movements  of  or  displacements  of  the  anode ;  and 
of  attention  to  the  maintenance  of  a  constantly  moist  state  of  the  anodal 
and  cathodal  contacts. 

These  principles  and  facts  have  led  to  the  application  of  galvanic 
currents  for  the  production  of  a  state  of  anesthesia  of  hypersensitive 
dentin  ;  and  the  results  of  experimentation  in  this  direction  have  proven 
that  the  same  eifects  have  followed  here  as  have  occurred  in  the  softer 
tissues. 

The  extreme  sensitiveness  of  the  teeth  to  electrical  currents  and  their 
resistance  to  the  passage  of  electrical  force  were  obstacles  to  the  earlier 
application  of  this  method  of  treatment  in  dentistry.  The  absence  of 
means  to  control  the  current  strength  (the  amperage)  and  to  reduce  the 
pressure  (the  voltage)  to  the  capacity  of  the  teeth  prevented  experi- 
mentation in  this  direction  until  within  a  comparatively  recent  period. 

The  current  strength  that  is  tolerable  at  the  commencement  of  the 
application  is  so  small  as  to  be  scarcely  measurable  in  many  instances. 
To  produce  this  small  current,  either  the  battery  voltage  must  be  low 
or  the  resistance  in  the  controller  exceedingly  high. 

Any  form  of  battery  whicli  is  constant  when  the  amperage  of  the 
individual  cell  is  from  one-fourtli  to  one-half  of  an  ampere  will  have 
sufficient  current  strength.  The  E.  M.  F.  may  be  from  one  to  two 
volts  per  cell. 

The  voltage  required  to  produce  the  necessary  electro-motive  force. in 
an  application  to  the  teeth  to  produce  dentinal  anesthesia  varies  from 
five  to  thirty.  For  children  and  Avhere  the  teeth  are  apparently  not 
dense,  ten  cells  sometimes  are  sufficient,  but  generally  fifteen  to  twenty 
are  needed.  The  cells  should  be  arranged  in  series  and  connected  in  a 
manner  which  enables  the  selection  of  any  number  to  produce  the  re- 
quired E.  M.  F.  for  any  given  case  and  to  permit  an  increase  of  cells 
during  the  administration. 

The  most  important  condition  of  the  electrical  force  for  the  purpose 
is  that  the  amperage  tiliall  he  iuconsiderahle,  since  high  amperage  is  intol- 
erable to  the  teeth.     As  the  most  efficient  results  are  produced  when  the 


202  PRELIMINARY  PREPARATION  OF  CAVITIES,   ETC. 

recorclod  nnipcraj^e  is  not  over  three-tentlis  of  a  miiliainiK'rc,  the  use  of  a 
current  of  liio-li  amperage  is  unnecessary,  and  it  is  attended  with  distress. 
Hiii'h  voltage  is  ecjually  painful,  as  the  endeavor  to  force  the  current 
against  the  resistance  of  the  dentin  results  in  electrical  irritation,  as 
already  described. 

The  chlorid  of  silver  cell  is  probably  the  one  best  suited  for  the 
purpose,  as  its  electro-motive  force  remains  practically  constant  under 
various  conditions.  The  K.  M.  F.  of  each  cell  is  about  one  volt ;  the 
internal  resistance  eight  ohms;  the  strength  one-fifth  of  an  ampere. 
This  battery  on  account  of  its  constancy  and  durability  is  largely  used 
in  electro-medical  apparatus.  It  is  now  furnished  dry,  and  is  more 
acceptable  as  being  less  troublesome  on  this  account. 

The  dry  Leclanche  battery  is  also  one  of  the  best  forms,  as  it  is  an 
open-circuit  battery.  As  long  as  the  circuit  is  open  there  is  no  action 
in  the  cell  and  consequently  there  is  no  loss. 

At  present  these  two  forms  of  galvanic  battery  cell  ap})ear  to  be  the 
kinds  best  adapted  for  the  purpose  of  inducing  electrical  osmosis. 

The  storage  battery  may  also  be  used  with  advantage,  but  the  plates 
should  be  small  ;  each  cell  should  contain  but  three  plates  to  give  the 
proper  degree  of  current  strength.  AVhen  the  plates  are  3x3  inches 
the  normal  amperage  at  eight  hours'  discharge  is  five-eighths  of  an 
ampere.  The  voltage  of  each  cell  is  two.  This  when  discharged  under 
the  resistance  required  for  application  to  sensitive  dentin  in  cataphoric 
work  should  have  a  capacity  for  800  applications,  providing  waste  of 
current  strength  does  not  occur  from  accidental  short-circuiting. 

The  life  of  a  chlorid  of  silver  dry  cell  battery  is  stated  to  be  700 
hours  of  cataphoric  work  under  a  high  resistance  of  tissue,  but  it  must 
be  remembered  that  the  continuance  of  energy  of  all  forms  of  battery  is 
varied  by  the  resistance  and  the  conversion  of  electrical  energy  into  heat 
by  the  controller  which  regulates  the  amperage  and  the  voltage.  This 
principle  applies  to  all  sources  of  electrical  force. 

The  coutroUer  which  at  present  ajipears  best  adapted  to  be  interposed 
between  the  battery  and  the  anode  is  the  AVillms  controller,  which,  as 
before  stated,  should  be  constructed  with  a  resistance  at  the  highest 
point  of  at  least  400,000  ohms.  The  gradations  of  resistance  decrease 
from  this  through  112  contact  points.  These  permit  a  very  gradual 
reduction  of  the  resistance  as  the  switch  is  conveyed  from  point  to 
point  in  the  circle.  This  controller  also  has  the  advantage  of  being 
moderate  in  cost  and  easily  procurable. 

An  important  adjunct  of  any  apparatus  is  a  reliable  villi iampercmeter. 
This  should  have  a  scale  to  record  divisions  of  fortieths  of  a  milliampere, 
from  the  fact  that  the  amperage  of  the  current  through  the  dentin  is  fre- 
quently efficient  at  less  than  two-tenths  of  a  milliampere.     The  milli- 


DENTINAL  ANESTHESIA   BY  ELECTRICAL   OSMOSIS.  203 

amperemeter  also  aids  in  detecting  leakage  of  current,  as  Mdiere  the 
indicated  amperage  exceeds  five-tenths  milliampere  there  is  reason  to 
suspect  imperfection  of  the  insulation  of  the  tooth.  In  this  case  a 
longer  period  than  usual  will  be  required  to  effect  the  anesthetization, 
and  the  decree  of  this  effect  mav  be  less. 

The  use  of  the  direct  current  generated  by  the  dynamo  is  of  ques- 
tionable utility  as  compared  with  the  current  from  a  battery.  The 
current  from  the  dynamo  is  subject  to  changes  of  voltage  and  the 
amperage  is  liable  to  fluctuations  consequent  upon  alterations  of  the 
load  in  the  general  circuit.  This  instability  causes  a  series  of  pulsat- 
ing shocks  upon  sensitive  dentin  and  the  pulp,  which  react  with  the 
expression  of  pain.  The  possibility  of  the  transmission  of  severe 
shock  through  accidental  grounding  or  defective  apparatus  where  such 
excessive  voltage  is  used  is  another  and  sufficient  reason  why  the 
steady  and  low-voltage  current  of  a  battery  is  preferable  for  this  class 
of  operations. 

TECHNIQUE   OF    THE    ADMINISTRATION. 

At  the  present  period  cocain  has  been  found  to  be  the  most  effective 
anesthetic  for  obtunding  dentinal  sensitivity  by  electrical  osmosis.  It 
is  used  in  strength  varying  from  12  to  24  per  cent.,  and  by  some  as 
high  as  40  per  cent,  has  been  used  ;  li  grain  of  one  of  the  salts  of 
cocain  added  to  5  minims  of  water  procures  a  solution  of  24  per  cent. ; 
to  7|-  minims,  18  per  cent.  ;  to  10  minims,  12  per  cent. 

The  salts  of  cocain  which  have  been  used  are  the  hydrochlorid  and 
the  citrate.  Each  is  efficient  in  the  strength  stated.  The  resistance  of 
cocain  citrate  is  for  12  percent,  solution  234  ohms;  for  24  percent. 
153  ohms.  The  resistance  of  cocain  hydrochlorid  is  for  12  per  cent, 
solution  80.85;  for  24  per  cent.  61.25.  These  provings  indicate  that 
the  hydrochlorid  is  the  better  salt  of  cocain  for  the  purpose.^ 

The  tooth  to  be  operated  upon  is  isolated  by  means  of  a  rubber  dam 
and  is  ligated  at  the  cervix  to  prevent  leakage  of  current.  If  there  are 
metallic  fillings  in  the  tooth,  these  should  be  covered  with  a  coat  of 
varnish  carefully  laid  on  and  dried.  Tin's  precaution  docs  not  alwavs 
possess  the  value  claimed  for  it,  as  the  dentin  beneath  a  metal  filling, 
because  of  its  density  or  lack  of  porosity,  will  not  convey  the  current 
as  well  as  the  carious  matter  and  the  softer  dentin  of  the  fresh  cavity. 
In  some  cavities  where  caries  has  occurred  at  the  cervix  above  srold 
fillings,  and  which  do  not  permit  of  complete  isolation  of  the  fillings, 
the  cataphoric  influence  is  not  interfered  witli. 

The  carious  matter  should  not  be  completely  removed  and  need  onlv 
be  partially  dried.     The  cavity  is  loosely  filled  with  a  small  pledget 

'The  writer  is  indebted  for  the  determination  of  these  resistances  of  cocain  sohitions, 
etc.,  to  Mr.  A.  AV.  Schramm,  of  the  University  of  Pennsylvania. 


204  PRELIMI^'ABY  PREPARATION   OF  CAVITIES,   ETC. 

of  lint  .saturated  witli  tlic  solution  of  eocain.  The  anode,  the  ])oint  of 
which  is  of  platinum,  is  covered  with  a  thin  stratum  of  lint  Avhicli  is 
dipjxHl  in  the  solution  and  inserted  in  the  cavity  in  contact  with  the 
pledo-et  ])reviously  introduced.  The  cathode,  which  should  he  at  least 
one  and  a  half  inches  in  diameter,  is  placed  at  a  convenient  place  on 
the  face  or  neck.  The  desired  number  of  cells  are  placed  in  circuit 
with  the  controller  at  zero. 

All  being  ready,  the  switch  is  placed  on  the  first  contact  point.  At 
this  moment,  however  great  the  resistance  of  the  controller,  a  slight 
sensation  is  sometimes  experienced,  but  at  once  the  switcli  may  be 
passed  slowly  over  the  contacts  until  some  sign  from  the  patient  indi- 
cates that  the  current  is  being  felt.  Here  it  is  retained  until  subsidence 
of  the  sensation  occurs,  when  the  resistance  of  the  controller  should 
be  very  gradually  lessened.  This  process  is  continued,  keeping  con- 
stantly within  the  limit  of  pain ;  at  length  the  switch  may  be  more 
rapidly  advanced.  AVhen  this  can  be  done  without  thrill,  the  indication 
is  that  anesthesia  is  complete.  The  switch  is  then  carried  back  to  the 
zero  point,  when  the  excavation  may  be  conducted. 

Where  it  is  necessary  to  remove  the  rubber  (as  the  solution  of  eocain 
is  strong)  the  preparation  should  be  previously  w^ished  away  to  prevent 
any  of  it  from  being  swallowed. 

The  i^eriod  of  administration  varies  from  eight  to  fifteen  minutes 
in  ordinary  cases  where  the  indicated  amperage  is  from  y'^  to  -^-^  milli- 
ampere.  When,  however,  the  dentin  is  dense,  as  where  denudation  has 
taken  place  by  attrition,  a  longer  time  is  required  to  efi^ect  penetration 
bv  the  eocain.  Also  where  from  any  condition  the  indicated  amperage 
at  first  is  ^j^j-  milliampere  or  less,  time  and  patience  are  demanded. 
The  loss  of  time  is  more  apparent  than  real,  since  there  usually  is  a 
direct  relation  between  the  pain  limit  at  very  low  amperage  and  high 
sensitivity ;  what  is  ap])arently  lost  in  the  time  of  the  application  is 
gained  in  the  after  facility  of  instrumentation. 

The  sphere  of  the  action  extends  throughout  the  cavity,  but  to  a 
somewhat  less  degree  at  the  extreme  lateral  margins,  and  more  particu- 
larly at  the  occlusal  margin.  Here  usually  no  more  than  a  normal 
degree  of  sensitivity  is  found,  which  appears  to  be  due  to  the  fact  that 
in  making  the  retentive  undercutting  this  procedure  may  extend  beyond 
the  sphere  of  the  complete  influence  of  the  eocain.  The  eifect  is  most 
pronounced  when  the  application  is  made  directly  to  the  carious  matter. 
In  this  case  the  diffusion  is  greater  than  when  the  caries  is  freely  re- 
moved, for  the  reason  that  in  the  latter  case  the  current  seeks  the  line  of 
least  resistance  toward  the  pulp.  It  follows  from  this  that  when  all 
parts  of  the  cavity  are  equidistant  from  the  pulp,  the  action  should  be 
more  effective   throughout  upon  the  surface  of  the  dentin.      This  is 


DENTINAL  ANESTHESIA  BY  ELECTRICAL    OSMOSIS.  205 

proven  to  be  the  case  from  the  profound  effect  in  cavities  upon  buccal 
and  labial  surfaces  and  in  shallow  cavities  of  occlusal  surfaces.  Besides 
the  less  diifusion  of  the  cocain  when  the  carious  matter  is  removed, 
a  degree  of  electrical  force  which  in  the  former  case  is  easily  tolerated 
becomes  painful.  These  facts  make  conclusive  the  importance  of  retain- 
ing some  of  the  carious  contents  of  the  cavity. 

An  explanation  of  the  influence  of  the  current  is  found  in  the  prin- 
ciples and  examples  given  on  page  194.  As  the  anode  is  put  in  con- 
nection with  the  lint  saturated  with  the  cocain  solution  the  fluids  of  the 
tooth  advance  toward  the  pulp  through  the  canaliculi,  their  place  being 
taken  by  the  solution  of  cocain.  At  the  same  time  it  is  observed 
that  loss  of  fluid  from  the  lint  occurs,  necessitating  additions  to 
maintain  the  proper  wetness,  some  loss  of  water  taking  place  by 
evaporation. 

Conditions  Infliioicing  Tolerance  of  the  Current. — As  already  stated, 
when  the  electrical  force  is  brought  into  connection  with  the  carious 
matter  the  irritation  caused  bv  the  current  is  of  triflino^  deg-ree  and 
soon  subsides,  indicating  that  the  anesthetic  eifect  has  been  produced  ; 
but  when  the  cavity  is  denuded  of  caries  the  above-stated  degree  of 
current  force  is  not  so  tolerable,  the  irritation  continues  longer  and 
does  not  subside  in  the  same  manner,  but  the  effect  upon  the  tissue  is 
nearly  if  not  quite  as  marked.  The  nearer  the  bottom  of  the  cavity 
is  to  the  pulp,  the  greater  the  irritation.  Hence  in  this  condition  it 
becomes  necessary  to  begin  with  a  low  degree  of  voltage.  While  in 
the  one  case  fifteen  cells  may  be  selected,  in  the  other  ten  cells  are 
more  satisfactory. 

To  avoid  the  removal  of  caries  the  condition  of  the  dentin  as  regards 
sensitivity  should  be  tested  at  the  line  of  its  connection  with  the 
enamel. 

Some  stress  has  been  laid  upon  the  necessity  for  rendering  the  solu- 
tion of  cocain  more  highly  conductive.  This  claim  is  probably  more 
theoretical  than  practical  in  its  character,  since  experience  with  the 
solutions  given  indicates  that  the  conductivity  is  sufficient,  and  that  the 
resistance  is  more  to  be  looked  for  in  the  dentin  than  in  the  solution, 
and  that  when  the  tooth  has  become  tolerant  of  the  current  at  a  com- 
paratively low  voltage  an  increase  of  pressure  of  the  current  is  suf- 
ficient to  complete  the  anesthesia. 

The  form  of  the  platinum  anode  should  be  such  as  to  permit  its 
easy  entrance  into  the  cavity  when  its  point  is  covered  with  a  layer  of 
absorbent  lint.  For  all  cavities  in  the  approximal  surfaces  and  in  most 
occlusal  positions  an  excellent  form  of  anode  is  made  by  curling  the 
end  of  a  fine  platinum  wire  (No.  25)  into  a  flat  knot,  or  forming  it  in  a 
loop.     On   the   loop   a   properly   sized   piece  of  lint   may  be  gathered. 


206 


rRELIMINARY  PBI'jrARATTOX   OF  CAVITIES,   ETC. 


This  may  be  packed  into  the  cavity  and  secured  with  additional  lint 
when  required.  This  method  is  a  self-sustaining  one.  The  connection 
between  the  free  end  of  the  anode  and  conducting  cord  is  made  with  a 
spring  clip,  as  shown  in  Fig.  155. 

For  labial  and  buccal  surfaces  two  or  more  small  points  to  screw 
into  a  common  handle  are  sufficient  (see  Fig.  154).     These  have  to  be 

1m<;.  ir,4. 


Dental  anodes  fur  cataphoresis. 

held  in  situ.     A  form  and  arrangement  to  make  these  self-sustaining 
offers  an  important  field  for  inventive  skill. 

Fig.  155. 


Snap  and  wire  electrode. 


A  convenient  cathode  electrode  is  shown  in  Fig.  156.     In  this 
the  surface  is  recessed  to  receive  a  disk  of  amadou  (spunk)  or  cottonoid, 


Fig.  156. 


Cathode  for  cataphoresis. 

one  and  a  half  to  two  inches  in  diameter,  which  retains  an  abundance 
of  a  solution  of  sodium  chlorid  to  maintain  contact.  The  surface  is 
platinized  to  prevent  corrosion.  The  reverse  side  has  the  usual 
socket  to  receive  the  conducting  cord,  which  is  placed  in  a  projection 
intended  to  pass  through  an  opening  in  the  band  which  supports  the 
rubber  dam. 

It  is  indifferent  where  this  electrode  is  placed  ;  the  objects  to  be 
attained  are  to  lessen  the  resistance  as  much  as  possible  and  to  secure 
constant  apposition  with  the  surface  with  which  it  is  connected.  If  the 
person  be  comparatively  lean,  the  face  before  the  ear  is  to  be  preferred. 


DENTINAL  ANESTHESIA    BY  CHEMICAL  AGENTS.  207 

When  there  is  much  adipose  tissue  on  the  face,  the  usual  negative  hand 
electrode,  covered  with  a  small  wet  napkin  to  maintain  close  contact, 
may  be  better  than  the  application  to  the  face  ;  but  in  general  the  nearer 
the  cathode  is  placed  to  the  angle  of  the  jaw,  the  quicker  and  surer  is 
the  result  of  the  administration. 

The  action  of  cocain  administered  in  this  manner  is  profound.  The 
effect  is  primarily  upon  the  contents  of  the  canaliculi,  as  is  shown  in 
the  cataphoric  treatment  of  shallow  cavities.  After  superficial  anes- 
thesia has  been  established  much  lateral  cutting  will  later  elicit  a  degree 
of  pain  ;  in  deep  cavities  nearing  the  pulp,  the  effect  extends  to  that 
organ.  The  recurrence  of  sensitivity  takes  place  within  a  few  hours. 
No  injury  appears  to  follow. 

This  method  of  treatment  is  little  required  where  the  degree  of 
hypersensitiveness  is  such  as  to  yield  to  desiccation  of  the  dentin  or 
the  application  of  carbolic  acid  combined  with  caustic  potassa  ("  Robin- 
son's Remedy ").  But  when  the  pain  attending  excavation  requires 
active  treatment,  such  as  the  employment  of  zinc  chlorid  or  general 
anesthesia,  the  cataphoric  method  is  far  preferable  to  either,  and  is 
nearly  certain  of  giving  relief.  Tlie  results  of  successful  cataphoresis 
are  marvellous,  and  it  may  be  truly  stated  that  no  advance  of 
recent  years  in  the  therapeutic  treatment  of  the  teeth  is  comparable 
to  this.^ 

Cautious  excavation  is  required  after  cataphoric  treatment,  as  in  the 
absence  of  sensitivity  indiscriminate  cutting  may  needlessly  encroach 
upon  the  pulp.  In  case  exposure  really  exists  the  action  of  cocain  does 
not  prejudice  conservative  treatment  of  the  pulp.  AVhen  devitalization 
is  determined  upon,  the  anesthesia  facilitates  this  procedure.  As  stated 
in  Chapter  XVI.  cocainization  may  be  then  continued  either  cata- 
phorically  or  by  instillation.  Should  arsenous  acid  be  selected  as  the 
devitalizing  agent,  cocainization  may  be  used  as  a  preparatory  measure 
to  avoid  arsenical  irritation. 

The   Chemical  Treatment. 

Under  tliis  head  are  included  the  application  of  warmed  air,  the  use 
of  coagulants,  notably  carbolic  acid  or  zinc  chlorid,  and,  in  combination 
with  these,  one  of  the  essential  oils,  preferably  oil  of  cloves,  for  reasons 
stated  below. 

"Warmed  Air. — This  metliod  is  of  great  value  in  subacute  cases. 
It  is  especially  serviceable  for  the  cavities  of  incisors  and  biscuspids  and 
others  of  easy  access.     The  effect  here  produced  is  due  to  the  depriva- 

^  For  further  study  of  this  subject,  see  "  International  System  of  Electro-Thera- 
peutics," Section  C,  p.  1  et  seq.,  Peterson ;  also,  "  Foundation  Principles  of  Dental 
■Cataphoresis,"  by  Dr.  Price,  Items  of  Interest,  vol.  xx.  p.  345. 


208 


PRELIMINARY  PREPARATION  OF  CAVITIES,   ETC. 


tion  of  the  tissue,  to  a  greater  or  less  degree,  of  one  of  its  elements,  viz. 
water,  and  it  is  more  effective  in  teeth  of  dense  structure,  since  the  sur- 
face of  these  is  more  easily  desiccated  than  the  softer  teeth.  If  it  were 
possible  to  remove  all  the  water  of  the  tissue  from  the  surface  to  the 
depth  of  the  irritated  part  all  sensitivity  would  thereby  be  overcome,  but 
generally  this  can  be  only  imperfectly  done ;  nevertheless,  the  benefit 
is  generally  considerable.  This  means  is  easily  and  quickly  applied, 
and  as  it  presents  the  simplest  method  in  the  cases  where  it  is  applicable 
it  forms  therefore  the  easiest  and  most  available  ]>rocedure  for  this 
purpose. 

The  warmed  air  may  be  produced  by  heating  the  bull)  of  a  warm- 
air  SYRINGE  (Fig.  157)  over  a  lamp  or  Bunsen  burner,  when  a  continu- 

FiG.  157. 


Warm-air  syringe. 


ous  stream  of  air  is  forced  through  the  nozzle  into  the  cavity.  Some  tact 
is  required  to  deliver  the  heated  air  in  a  manner  to  cause  the  least  pain 
by  its  impingement.  If  the  nozzle  be  held  too  far  away  from  the  tooth 
the  stream  of  air  in  passing  through  the  atmosphere  takes  along  with  it 
so  much  of  the  surrounding  cool  air  as  to  cause  pain,  and  if  held  too 
close  the  heat  is  equally  painful.  In  all  cases  the  abstraction  of  the 
water,  even  when  the  degree  of  heat  is  avcII  balanced,  produces  some 

Fig.  158. 


Electric  warm-air  syringe. 


unpleasant  sensation,  which  soon  passes  away  and  after  a  few  moments 
the  case  is  reduced  to  a  state  of  slight  and  simple  sensitiveness.     The 


DENTINAL  ANESTHESIA   BY  CHEMICAL  AGENTS.  209 

blast  should  be  gently  a])plied  at  first  at  intervals  of  a  couple  of  sec- 
onds ;  when  the  pain  induced  by  the  abstraction  of  the  water  some- 
what diminishes,  the  force  should  l^e  increased  and  made  continuous, 
Avhen  in  most  cases  the  excavation  may  be  continued.  The  air  may 
also  and  preferably  be  heated  by  an  electric  warm-air  syringe  (Fig. 
158),  which  has  tlie  advantage  of  maintaining  an  even  degree  of  heat. 

As  stated  before,  this  means  is  of  less  use  with  soft  teeth,  and  fre- 
quently fails  when  the  teeth  have  a  high  grade  of  sensitivity  which 
appears  to  be  due  to  constitutional  conditions, — where  the  sensitivity  is 
not  confined  to  the  surface  of  the  tissues  immediately  beneath  the  caries 
but  pertains  to  the  whole  of  the  dentin. 

Preparatory  to  the  use  of  heated  air,  the  application  to  the  cavity 
of  absolute  alcohol  is  serviceable,  on  account  of  its  high  affinitv  for 
water. 

Carbolic  Acid. — This  substance,  \\hile  of  little  efficiencv  in  con- 
trolling acute  sensitivity,  is  of  benefit  in  moderating  that  condition. 
Its  efficacy  is  increased  by  adding  to  it  a  proportion  of  one-third  of  oil 
of  cloves,  which  latter  has  some  anesthetic  intluence.  When  other 
more  active  means  are  not  admissible  and  the  effect  is  not  immediately 
satisfactory,  a  better  result  is  produced  by  placing  this  combination  in 
the  cavity  and  sealing  it  in  with  zinc  phosphate  until  a  subsequent 
visit,  as  before  described.  On  account  of  the  feeble  affinity  of  carbolic 
acid  for  water,  the  obtundent  effect  is  facilitated  by  the  previous  partial 
desiccation  of  the  surface  of  the  cavity  by  warm-air  blasts.  Carbolic 
acid  in  combination  with  caustic  potassa,  equal  parts  of  each  (Robin- 
son's Remedy),  is  often  of  much  service  in  subacute  sensitivity.  The 
preparation  should  be  laid  in  the  cavity  in  contact  with  the  denuded 
dentin  and  should  be  allowed  to  remain  until  it  deliquesces. 

Carbolic  acid  in  combination  with  tannic  acid  is  also  serviceable  Avhen 
sealed  in  the  cavity  l)y  an  impermeable  temporary  stopping. 

Zinc  Chlorid. — Of  all  substances,  when  not  interdicted  by  proximity 
of  the  dental  pulp,  zinc  chlorid  is  the  most  efficient  of  the  topical 
remedies  for  the  condition  under  consideration.  Its  action  is  explained 
by  the  double  power  of  its  affinity  for  water  and  its  extreme  coagulating 
effect  upon  albumin.  It  is  evident  that  if  the  tissue  be  deprived  of  two 
of  its  elements  the  function  of  sensitivity  must  be  impaired  or  destroyed. 
In  the  degree  to  which  this  action  takes  place  the  tissue  loses  its  capacity 
for  irritation. 

As  zinc  chlorid  in  concentrated  solution  is  an  active  escharotic  to 
organic  tissue,  it  must  be  employed  with  caution.  After  paralyzing  the 
vital  resistance  of  the  part  its  action  is  by  combining  in  definite  ])ropor- 
tions  with  the  albuminous  elements  of  the  structure.  It  has  the  fur- 
ther property  of  an  excessive  affinity  for  M^ater,  which  enables  one  to 

14 


210  PRELIMINARY  PREPARATION   OF  CAVITIES,   ETC. 

arrest  its  action  by  sufficient  irrigation  to  remove  all  traces  of  the  salt 
from  the  cavity.-  Its  active  coagulating  power  renders  it  a  valuable 
agent  in  excessive  dentinal  sensitivity  where  there  is  not  close  ])roximity 
of  the  pulp,  and  its  safety  is  ensured  by  the  fiicility  with  which  any  re- 
mains of  the  salt  may  be  taken  up  with  watei-. 

Unless  employed  in  excess  and  too  long  continued  the  action  of  the 
zinc  chlorid  does  not  pass  beyond  the  zone  of  the  exalted  tissue,  which, 
as  we  are  aware,  generally  is  of  limited  depth.  The  cessation  of  the 
pain  produced  by  it  indicates  the  time  for  its  removal,  when  usually 
the  dentin  will  be  found  to  be  insensitive.  There  are  instances,  how- 
ever, when  no  apparent  effect  is  produced,  which  can  only  be  satisfac- 
torily explained  on  the  ground  that  the  vital  resistance  of  the  tissue  is 
sufficient  to  overcome  the  coagulative  power  of  the  zinc  salt. 

In  general,  zinc  chlorid  must  be  regarded  as  an  entirely  safe  agent 
if  used  with  discretion.  It  is  more  applicable  to  shallow  cavities  which 
are  so  situated,  or  are  of  such  form,  as  to  require  much  formative  cutting 
at  the  margins  of  the  cavities,  as  in  buccal  and  labial  surfaces  and  in  the 
very  superficial  cavities  of  incisors  and  bicuspids.  A  warning,  however, 
should  be  presented  that  as  the  pulp  cornua  of  incisors  frequently  pro- 
ject near  the  surface,  particularly  in  the  young  subject,  considerable  care 
is  here  required  in  any  but  shallow  cavities  of  decay.  If  it  were  used 
in  excess  and  its  action  extended  there  would  always  be  danger,  as 
its  energies  would  not  cease  until  the  affinities  of  the  whole  amount 
were  satisfied.  In  deep  cavities  the  effect,  particularly  in  soft  teeth, 
would  eventuate  in  the  ultimate  devitalization  of  the  pulp.  It  fol- 
lows, therefore,  that  it  would  be  improper  to  seal  up  any  quantity  of 
this  substance  in  a  cavity. 

The  action  of  zinc  chlorid  is  terminated  when  the  excess  is  removed 
and  the  cavity  irrigated  with  water.  The  affinity  it  has  for  water 
quickly  removes  the  excess  and  soon  deprives  the  tissue  of  the  remain- 
ing portion. 

When  cavities  are  deep  and  it  is  found  necessary  to  resort  to  this 
agent  the  surface  of  the  deeper  parts  should  be  protected  by  an  insoluble 
coating,  after  which  the  margins,  where  the  sensitivity  is  acute,  may  be 
acted  upon  without  detriment.  Here  it  is  requisite  to  remove  the  deep 
caries,  desiccate  the  surface  and  make  a  coating  with  a  varnish.  For 
this  purpose  red  gutta-percha  rubbed  in  chloroform  is  applicable,  since 
it  may  be  deftly  applied  to  any  given  part  and  when  the  chloroform  has 
escaped  is  protective. 

To  properly  apply  zinc  chlorid  it  is  highly  important  to  isolate  the 
tooth  by  means  of  rubber  dam  to  protect  the  gum  and  to  prevent  the 
entrance  of  moisture.  Its  affinities  for  water  are  so  great  that  even 
the  vapor  of  the  mouth  dilutes  it  so  much  as   to  lessen  its  power.     The 


DENTINAL  ANESTHESIA   BY  CHEMICAL  AGENTS.  211 

form  in  which  it  is  best  to  employ  it  is  the  saturated  deliquesced  salt, 
which  is  taken  from  a  bottle  containing  the  salt  in  excess.  The  fluid 
is  introduced  on  a  ])ledget  of  cotton  and  is  permitted  to  remain  until 
the  pain  occasioned  by  it  has  ceased.  It  will  be  found  that  there  are 
two  periods  of  pain  :  the  first  from  its  irritation  of  the  fibrils  in  the 
bottom  layer  of  the  caries,  and  then  again  when  it  has  reached  the 
zone  of  exalted  dentin  a  little  beneath  this  ultimate  layer  of  decay. 
It  follows,  if  the  caries  has  all  been  previously  removed  and  the 
sensitive  tissue  interdicts  further  cutting,  that  but  one  period  of  pain 
is  encountered.  The  cutting  should  therefore  be  deferred  until  after 
the  second  period  of  pain  has  passed.  The  disregard  of  this  considera- 
tion has  sometimes  cast  discredit  upon  the  efficiency  of  this  sovereign 
remedy. 

It  is  requisite  that  the  chlorid  be  chemically  pure,  and  the  fused 
form  is  preferable  to  the  crystals  of  the  shops. 

The  PAIN  attending  the  application  is  sometimes  extreme  for  a  mo- 
ment. This  can  be  moderated  by  air-drying  the  cavity  and  dressing  it 
with  carbolic  acid,  which  does  not  seem  to  prevent  the  action  of  the 
chlorid. 

To  avoid  the  loss  of  time  which  may  be  occasioned  by  the  slow 
action  it  is  advisable,  after  securing  the  dam  at  the  neck  of  the  tooth 
by  a  ligature,  to  very  tightly  tie  the  free  portion  of  the  rubber  a  short 
distance  from  the  tooth  with  a  strong  ligature,  and  after  cutting  away 
the  excess  of  rubber  some  other  service  may  be  rendered.  When  the 
pain  has  ceased  the  case  may  be  proceeded  with,  or  the  excess  of  chlorid 
may  be  thoroughly  washed  out  and  the  cavity  temporarily  closed  until 
a  subsequent  time. 

Another  method  of  securing  the  action  of  zinc  chlorid  is  to  make  a 
paste  of  zinc  oxychlorid  and  fill  the  cavity  with  it.  Even  after  crys- 
tallization of  the  paste  takes  place'  it  contains  a  slight  excess  of  the 
chlorid,  which  slowly  acts  upon  the  hypersensitive  tissue.  This  method, 
however,  is  not  adapted  to  deep  cavities,  and  care  must  be  exercised  con- 
cerning its  use  in  teeth  of  inferior  grade. 

Zinc  chlorid  is  an  extremely  valuable  remedy  when  the  previously 
<lescribed  agents  prove  insufficient  or  are  not  indicated. 

Conditions  u-hich  render  Zinc  Chlorid  inadmissible. — It  has  been 
stated  that  the  chief  danger  of  its  use  consists  in  the  liability  of  the 
coagulant  and  esciiarotic  action  reaching  the  pulp  in  deep  cavities. 
This  danger  is  further  enhanced  when  the  teeth  are  soft,  as  in  this  con- 
dition the  penetration  is  liable  to  be  greater  than  would  be  the  case  with 
dense  dentin.  The  same  caution  must  be  observed  when  the  structure 
is  incomplete,  as  it  is  in  the  teeth  of  young  subjects.  Even  here,  as 
•extreme  sensitiveness  is  always   found  at  the  peripheral  limits  of  the 


212  PRELIMINARY  PREPARATION  OF  CAVITIES,   ETC. 

tubules,  it  is  not  difficult  to  limit  the  action  to  this  part  by  the  means 
al)()vc  pointed  out  if  care  be  taken  in  the  required  procedures. 

The  Acids. — Chromic  and  nitric  acids  arc  of  service  in  extremely- 
shallow  cavities  of  very  high  sensitivity.  The  former  acts  by  coagula- 
tion of  the  organic  elements  of  the  dentin  and  the  latter  by  decom])osi- 
tion  and  solution.  To  apply  these  the  adjacent  tissues  require  to  be 
protected.  Each  should  be  carried  in  small  quantity  upon  a  gold 
])robe. 

Nitrate  of  silver  is  applicable  for  reducing  the  sensitivity  of  dentin 
after  the  removal  of  superficial  caries  or  when  by  abrasion  or  by  erosion 
the  exposed  tissue  is  intolerably  sensitive.  It  is,  however,  only  to  be 
used  in  the  back  of  the  mouth  on  account  of  the  discoloration  which  it 
produces. 

Chlorid  of  antimony  is  applicable  only  to  cases  of  exposed  cemen- 
tum,  where  it  is  claimed  that  it  is  equally  as  efficient  as  silver  nitrate^ 
and  has  not  the  objection  of  discoloring  the  tissue. 

General    Anesthesia. 

While  some  reluctance  should  exist  as  to  the  propriety  of  inducing 
general  anesthesia,  it  sometimes  becomes  necessary  to  resort  to  this 
means  of  alleviation.  Necessity  for  this  election  arises  where  the  sen- 
sitivity is  extreme,  when  the  previous  remedies  have  been  inefficient, 
and  when  from    the    nature  of  the  case  zinc  chlorid  is    inadmissible^ 

The  subjects  should  generally  be  adult  persons  of  intelligence,  who 
possess  moral  force  and,  having  confidence  in  their  adviser,  are  capable 
of  giving  the  requisite  indications  of  the  progress  of  the  anesthetic 
influences. 

Sulfuric  ether  is  the  most  suitable  anesthetic  to  be  employed,  and 
the  operative  procedures  should  be  performed  in  the  first  stage,  that 
of  peripheral  anesthesia.  At  this  period,  which  is  before  the  stage 
of  excitement  commences,  dentin  may  be  cut  without  the  slightest 
pain  being  felt.  This  is  an  important  consideration,  since  if  the  ad- 
ministration is  continued  into  the  period  of  excitement  nothing  can  be 
done,  and  if  it  is  conducted  to  a  full  degree  the  patient  is  not  manage- 
able. Also  the  subsequent  depression  is  to  be  avoided.  While  general 
anesthesia  in  the  first  stages  is  available  for  the  relief  of  dentinal  sensi- 
tivity, it  is  found,  on  the  contrary,  when  resorted  to  for  the  removal  of 
the  pulp,  as  may  occasionally  be  required  in  the  most  severe  cases  of 
congestion,  that  nothing  short  of  profound  anesthesia  will  suffice. 

When  the  first  stage  is  reached,  the  patient  being  conscious  and  able 
to  reply  to  questions,  the  cutting  is  commenced  ;  as  the  pain  returns  a 
few  more  inhalations  are  given,  when  another  part  of  the  cutting  may 
be  proceeded  with.     This  may  be  repeated  until  the  cavity  is  formed. 


GENERAL  ANESTHESIA. 


213 


Fig.  159. 


The  cuttino;  sliouKl  \y^  tiuickly  and  deftly  conducted.  The  amount  of 
ether  administered  i.s  far  less  than  is  required  to  induce  full  anesthesia, 
and  the  patient  suffers  far  less  depression  than  if  the  operation  were 
performed  without  this  means.  There  is  also  no  danger  of  shock,  since 
the  patient  is,  or  should  be,  intelligently  concerned  in  the  progress  of  the 
case.  If  the  condition  were  carried  into  the  second  stage,  when  excite- 
ment exists  and  alarm  is  aroused  in  addition  to  the  operative  interfer- 
ence, there  is  liability  to  shock,  which,  being  due  to  a  profound  impres- 
sion on  the  neryous  system,  is  not  liable  to  occur  when  the  patient 
concurs  in  all  the  steps  of  the  procedure. 

The  time  required  to  bring  about  a  sufficient  degree  of  dentinal 
anesthesia  frequently  is  less  than  two  minutes.  The  ether  should  be 
pure  and  should  be  giyen  with  a  free  supply  of  air  mixed  with  the 
yapor.  The  ordinary  custom  of  using  the  towel  to  enyelop  the  face  is 
questionable,  since  this  method  does  not  permit  enough  air  to  accompany 
the  ether  vapor. 

An  invaluable  inhaler  for  this  purpose  is  the  one  invented  by  Dr. 
Allis  (Fig.  159).  This  consists  of  an  oval 
frame  composed  of  a  series  of  wires  through 
which  passes  back  and  forth  a  continuous 
band  of  muslin.  The  layers  of  muslin 
are  near  each  other,  and  still  so  far  apart 
as  to  permit  the  free  passage  of  the  at- 
mosphere. The  correct  manner  is  to 
continuously  drop  the  ether  in  small 
quantity  upon  the  muslin  to  maintain  it 
at  an  even  degree  of  saturation. 

This  appliance  is  one  of  value  to  the 
dental  operator,  as  by  it  the  anesthetic 
state  can  be  more  quietly  brought  about 
with  less  of  the  characteristic  disturb- 
ances which  attend  the  usual  modes  of  applying  sulfuric  ether. 

The  use  of  chloroform  for  the  purpose  under  discussion  is  wholly 
inadmissible. 

The  mechanical  means  consist  in  the  use  of  temporary  fillings, 
which  may  be  either  metallic  or  non-metallic.  The  metallic  act  by 
inducing,  in  consequence  of  the  slight  irritation  of  thermal  conductivity, 
a  consolidation  of  the  subjacent  dentin,  which  in  time  obliterates  the 
tubules.  The  non-metallic  act  simply  as  a  protective  covering  to  the 
denuded  dentin.  Their  action  hence  is  more  tardy  than  that  which 
follows  the  use  of  the  former. 

The  metallic  stoppings  for  this  purpose  may  be  composed  of  either 
tin  foil  or  amalgam.     Each  of  these  requires  cavities  of  reasonably  good 


The  Allis  inhaler. 


214  PRELIMINARY  PREPARATION  OF  CAVITIES,   ETC. 

retentiveness,  therefore  they  arc  not  api)lical)le  to  shallow  cavities  of 
unsuitable  form. 

The  non-metallic  may  he  cither  iiutta-))crclia,  zinc  |)liosphatc,  or  zinc 
oxychlorid.  Tiie  two  latter  are  the  most  desirahle,  as  they  adhere 
to  any  well-dried  cavity,  and  havinij:;  some  irritatinu:;  inllucnce  on 
the  tissues  tend  to  induce  structural  consolidation  in  addition  to  their 
protective  action.  They  have,  howev(n',  the  disadvanta<j^c  of  suif'ering 
loss  l)v  chemical  solution,  and  unless  l<ej)t  under  close  ohservation  are 
delusive  and  in  many  instances  are  a  deceptive  means  of  preventing  the 
recurrence  of  decay.  In  the  employment  of  these  substances  due  care 
should  be  exercised  concerning  the  proximity  of  the  pulp,  in  which  cases 
the  previously  indicated  means  of  shielding  the  pul])  walls  should  be 
pursued. 

The  chief  disqualification  of  gutta-percha  is  its  lack  of  resistance  to 
attrition,  and  when  in  positions  shielded  from  wear  it  may  be  attacked 
by  low  forms  of  bacterial  life,  which  disintegrate  it. 

Mechanical  protection  of  cavities  is  most  applicable  to  teeth  of  a  low 
grade  of  structure  and  for  young  children  who  may  not  have  the  ability 
to  tolerate  the  more  active  means  needed  to  reduce  dentinal  sensitivity. 
For  these  cases  gutta-percha  stoppings  when  carefully  introduced  are  a 
great  boon,  since  they  protect  the  tissues  during  the  period  of  completion 
and  consolidation  of  the  teeth. 


CHAPTER   yill. 

PREPARATION  OF  CAVITIES— OPENING  THE  CAVITY— RE- 
MOVING THE  DECAY— SHAPING  THE  CAVITY— CLASSI- 
FICATION OF  CAVITIES. 

By   S.   H.   Guilford,   A.  M.,  D.  D.  S.,  Ph.  D. 


General  Considerations. — The  importance  of  the  proper  preparation 
of  a  cavity  for  the  insertion  of  a  filling  can  scarcely  be  oyerestimated. 
Upon  its  being  well  done  the  success  of  the  completed  operation  largely 
depends.  As  many  fillings  fail  from  lack  of  thoroughness  in  the  pre- 
paration of  the  cavity  as  from  any  other  cause. 

The  operator  should  not  be  actuated  by  haste,  but  should  be  deliber- 
ate, careful,  and  painstaking.  Each  stage  of  the  operation  should  be 
thoroughly  performed  in  order  that  when  completed  the  cavity  may  be 
in  the  best  possible  condition  for  the  reception  and  retention  of  the 
filling. 

The  operation  is  naturally  divided  into  three  stages  : 

1.  Opening  the  Cavity. 

2.  Removing  the  Decay. 

3.  Shaping  the  Cavity. 

Opening  the  Cavity. 

Every  cavity  to  be  excavated  must  first  be  opened,  so  that  it  may  be 
approached  and  operated  upon  at  all  points.  The  particular  manner  of 
doing  this  will  have  to  be  determined  by  the  extent  of  the  decay  and  its 
position,  but  in  all  cases  the  opening  must  be  as  full  and  free  as  the 
conditions  will  permit. 

The  accessibility  of  the  cavity  will  depend  upon  its  location.  Upon 
the  three  exposed  surfaces  of  a  tooth  crown  (occlusal,  lingual,  and  labial 
or  buccal)  access  to  a  cavity  is  usually  easy,  but  upon  the  unexposed 
surfaces  (a])proximal)  access  can  only  be  had  after  the  teeth  have  been 
pressed  apart.  For  methods  of  securing  temporary  separation  of  the 
teeth  see  Chapter  VI. 

A  cavity  U])on  an  exposed  surface,  if  small,  can  usually  best  be 
opened  by  the  use  of  some  form  of  engine  buk.  A  few  sizes  each  of 
the    forms    known    as    "  fissure,"    "  inverted-cone,"   and    "  round "   (or 

215 


21 G 


PREPARATION  OF  CAVITIES. 


^'rose-head")  are  shown  in  Figs.  160-162.  A  spear-pointcd  drill 
is  sometimes  used,  but  is  less  serviceable  on  account  of  its  tendency 
to  be  caught  or  broken  in  the  irregularities  of  the  cavity  orifice.  A 
modified  form  of  fissure  bur  has  found  much  favor  in  the  opening  of 
small  cavities  on  exposed  surfaces.     It  is  made  from  an  ordinarv  bur 


Fig.  IGO. 


V\r,.   Kil. 


Vu:.  liVl. 


Fissure  burs. 


luverted-coae  burs. 


Round  bur.' 


from  which  the  head  has  been  broken,  by  cutting  spiral  blades  on  the 
tapering  neck  of  the  shank.  Being  pointed,  round,  and  tapering  it 
easily  eiFects  an  entrance  into  the  cavity  and  enlarges  the  orifice  grad- 
ually and  symmetrically.     It  is  shown  in  Fig.  163. 

In  cavities  of  larger  size,  where  decay  has  made  more  progress,  the 
overhanging  walls  of  enamel  can  best  be  broken  down  by  chisels  of 
suitable  size  and  form.  Where  a  straight  chisel  can  be  employed  it 
will  be  found  most  efficient,  but  in  positions  difficult  of  access  one 
having  a  slight  curve  or  angle  may  need  to  be  employed.  Figs.  164  and 
165  represent  both  forms  as  well  as  the  sizes  usually  preferred.     The 


Fig.  163. 


Fig.  164. 


Fig.  165. 


Modified  fissure  bur  with 
tapering  point. 


Straiglit  chisels. 


Curved  chisels. 


width  of  the  blade  may  vary  from  one-sixteenth  to  one-eighth  of  an  inch, 
but  wider  ones  than  these  will  seldom  be  required. 

A  chisel  may  be  used  with  either  hand  pressure  or  mallet  force.  If 
the  former,  great  care  must  be  exercised  to  prevent  its  slipping  and 
causing  pain  or  possible  injury.  The  best  safeguard  in  its  use  is  to 
place  the  thumb  of  the  right  hand  on  the  tooth  being  operated  upon  or 
some  adjoining  one  and  use  it  as  a  fulcrum  or  pivot  upon  which  the 


REMOVING   THE  DECAY. 


217 


Fig.  166. 


instrument  may  move  in  a  eurve.  By  this  means  the  motion  of  the 
chisel  is  regulated  and  controlled  and  all  danger  of  slipping  avoided. 
It  will  sometimes  be  of  advantage  to  roughly  pack  the  interior  of  the 
cavity  with  cotton  or  spunk  to  receive  the  impact  of  the  instrument 
should  the  chisel  accidentally  be  forced  to  the  bottom  of  the  cavity. 

The  better  plan,  however,  in  most  cases,  is  to  employ  mallet  force 
for  the  cleavage  of  enamel  unsupported  by  dentin.  By  holding  the 
chisel  between  the  thumb  and  three  fingers  of  the  left  hand  and  resting 
the  little  finger  of  the  same  hand  on  an  adjacent  tooth  for  steadiness,  a 
smart  but  light  blow  of  a  mallet  in  the  right  hand  upon  the  end  of  the 
chisel  will  easily  and  painlessly  cleave  off  portions  of  the  enamel. 

In  opening  cavities  of  small  extent  or  limited  depth  upon  approxi- 
mal  surfaces  a  round  or  inverted-cone  bur  will  best 
serve  the  purpose,  but  where  caries  is  more  exten- 
sive and  the  surrounding  enamel  is  unsupported  by 
dentin  the  orifice  of  the  cavity  can  be  more  advan- 
tageously enlarged  by  means  of  a  delicate  chisel 
(shown  in  Fig.  1 66)  the  blade  of  which  is  bent  at  a 
slight  angle  to  the  shank  and  all  three  of  the  edges 
of  which  are  bevelled  to  convert  them  into  cutting 
edges.  This  instrument  will  be  found  especially 
useful  in  opening  cavities  of  medium  or  larger  size 
on  the  approximal  surfaces  of  the  incisors,  the  point 
doing  the  cleaving  and  the  side  edges  being  used  to 
smooth  the  enamel  margins. 

After  the  orifice  of  the  cavity  has  been  sufficiently 
enlarged  to  afford  a  full  vie^v  of  its  interior  the  next 
stage  of  the  operation  is  entered  upon — 


Delicate  three-sided 
chisel,  useful  for 
opening  cavities  on 
approximal  sur- 
faces. 


Removing  the  Decay. 

The  character  or  consistence  of  the  carious  structure  has  much  to 
do  with  the  method  and  means  employed  for  its  removal.  If  it  be  of 
the  semi-elastic  or  leathery  variety  so  often  found  in  the  teeth  of  young 
persons,  it  can  be  most  easily  removed  by  means  of  spoon-shaped  or 
round-bladed  excavators,  which  being  oval  or  circular  in  edge  out- 
line and  free  from  marginal  angles,  will  lift  and  separate  the  layers 
witliout  danger  of  injuring  the  underlying  healthy  dentin  and  with  the 
infliction  of  a  minimum  amount  of  pain.  Fig.  167  illustrates  this  kind 
of  instrument  in  some  of  its  forms,  selected  from  the  Darby-Perry  set. 

In  the  dark,  hard  variety  of  caries,  as  also  in  the  tchite,  chalky 
variety,  the  diiferent  forms  of  l)urs  and  excavators  will  be  found  best 
suited  for  the  purpose. 

In  tlio  removal  of  caries  care  should  be  exercised  to  inflict  as  little 


218 


PREPARATION  OF  CAVITIES. 


])ain  ii|)(>n  tlie  patient  as  possil)le.  To  this  end,  in  cavities  of  con- 
siderable extent,  it  is  best,  after  the  orifice  lias  been  sutticiently  enlarged, 
to  make  a  sweeping  cut  with  an  excavator  around  the  cavity  just  below 


Fk;.  167. 


1?   0  i?   1 


L)  i  }  r„i 


Excavators. 


the  enamel  line,  thus  freeing  the  decayed  portion  at  that  point.  Follow- 
ing this  the  remaining  portion  of  carious  dentin  should  be  removed  by 
placing  the  blade  of  the  excavator  near  the  bottom  of  the  cavity  and 
making  draw-cuts  toward  the  orifice.  To  cut  in  the  reverse  direction 
would  produce  uncomfortable  pressure  upon  the  most  tender  portion  of 
the  cavity,  and  possibly,  by  inadvertence,  expose  and  wound  the  pulp. 
AVhen  burs  are  employed  for  the  removal  of  caries  it  is  safest  to  use 
only  such  as  are  more  or  less  rounded  on  their  circumference,  such  as 
the  round  or  oval  forms,  for  they  more  nearly  conform  to  the  natural 
outline  of  the  cavity,  leave  no  angular  grooves  in  the  dentin  difficult 
or  impossible  to  perfectly  fill,  and  are  not  so  likely  to  injure  the  healthy 
subjacent  dentin. 

The  varieties  of  bur  known  as  the  inverted-cone  and  tvheel,  while  very 
useful  for  opening  cavities,  should  not  be  used  for  the  removal  of  caries 
in  deep  cavities,  because  of  the  irregularities  of  surface  which  their 
peripheral  angles  produce. 

Rapidly  revolving  burs  in  an  engine  handpiece  are  very  apt  to  cause 
pain  by  the  development  of  frictional  heat.  This  may  largely  be  pre- 
vented by  lifting  the  bur  at  short  intervals  and  allowing  it  to  run  free 
for  a  moment,  which  will  prevent  overheating  the  tooth  and  thus  avoid 
unnecessary  pain. 

Thorougli  excavation  of  the  cavity  and  the  removal  of  all  carious 
dentin  is  absolutely  essential  to  success.  To  allow  any  portion  of  it  to 
remain  and  trust  to  the  employment  of  germicides  for  its  sterilization 
is  running  the  risk  of  failure,  for  we  can  never  be  entirely  sure  of 
disinfection.  Besides  this,  there  is  no  good  reason  for  allowing  cari- 
ous dentin  to  remain. 

By  carious  dentin  is  meant  the  remains  or  debris  of  the  action  of 


EEMOVIXG    THE  DECAY.  219 

caries, — a  product  resulting-  from  this  disintegrating  action  upon  both 
the  organic  and  inorganic  constituents  of  dentin.  In  nearly  all  cavi- 
ties we  iind  tu-o  raricties  of  alfercd  tissue.  That  nearest  the  surface  is 
a  mass  of  thoroughly  disorganized  and  usually  decomposed  matter  filled 
with  micro-organisms.  Beneath  this  and  lying  next  to  the  healthy  den- 
tin there  is  a  zone  or  layer  from  which  the  calcium  salts  have  been  re- 
moved by  the  acid  solvent,  but  which  still  retains  its  original  form  and 
vitalitv.  This  layer  of  decalcified  dentin  may  be  allowed  to  remain, 
especially  in  the  bottom  of  a  cavity,  as  it  serves  to  protect  the  subjacent 
tissue  from  thermal  shock  and  will  in  the  great  majority  of  cases  be 
again  converted  into  normal  dentin  by  the  re-deposition  of  calcium  salts. 
As  a  precautionary  measure,  however,  it  should  be  treated  to  an  applica- 
tion of  some  germicide  such  as  carbolic  acid,  mercury  bichlorid,  for- 
malin (10  per  cent,  aqueous  solution),  or  oil  of  cinnamon,  before  the 
insertion  of  the  filling. 

Occasionally  caries  will  be  found  to  be  sclf-Umitcd.  In  such 
cases,  through  some  unexplained  change  of  conditions,  the  progress 
of  caries  has  been  checked  and  the  layer  of  decalcified  dentin  re- 
stored to  its  previous  normal  condition.  AYhere  this  has  taken  place 
the  restored  tissue  is  usually  of  a  darker  color  than  ordinary  dentin, 
and  on  this  account  may  be  mistaken  for  carious  dentin  and  removed. 
It  is,  however,  easily  distinguished  from  caries  by  its  hardness,  and 
should  in  no  case  be  removed  except  from  the  sides  of  a  cavity,  and 
then  only  when  its  dark  color  showing  through  the  walls  would  prevent 
the  cavity,  after  being  filled,  from  having  that  clear  and  clean  appear- 
ance which  it  should  possess. 

With  some  practitioners  it  is  the  custom  to  prepare  a  cavity  dry, 
because  in  this  way  the  operation  is  more  rapid  and  usually  less  painful. 
In  such  case  the  rubber  dam  is  ajiplied  first  of  all  and  the  operations  of 
0})ening,  cleansing,  and  shajiing  the  cavity  are  all  performed  without 
the  presence  of  moisture.  Repeated  applications  of  warm  air  from  a 
syringe,  at  intervals  during  the  operation,  desiccate  the  dentin  and  di- 
minish its  power  of  sensation.  Others,  in  order  to  avoid  the  unpleasant- 
ness to  the  patient  of  having  the  dam  in  position  for  so  long  a  time, 
prepare  the  cavity  roughly  in  the  presence  of  moisture,  then  apply  the 
dam,  dry  the  tooth  thoroughly,  and  finish  the  operation. 

Whichever  plan  is  adopted  it  is  absolutely  necessary,  in  all  cases,  to 
finish  the  preparation  with  the  dam  on  and  the  tooth  dry,  for  it  is  only 
after  a  tooth  has  been  deprived  of  its  moisture  that  we  are  able  to 
decide  whether  all  the  niceties  of  preparation  have  been  successfully 
carried  out.  Certain  marginal  and  structural  defects  that  are  not 
noticeable  while  the  tooth  is  moist  are  plainly  revealed  after  it  has  been 
(h'icd. 


220  PREPARATION  OF  CAVITIIJS. 

Shaping  the  Cavity. 

This  is  one  of  the  most  important  of  all  operations  associated  with 
the  stopping  of  a  cavity,  for  according  as  it  is  properly  or  improperly 
performed  will  sncccss  or  failnre  resnlt.  Too  much  stress  cannot  be 
laid  upon  its  importance,  nor  too  great  care  be  exercised  in  its  accom- 
plishment. 

Inasmuch  as  a  filling  is  retained  in  place  mechanically  it  follows  that 
the  cavity  must  be  of  such  shape  as  to  favor  retention.  To  this  end  it 
should  be  larger  within  (at  least  at  certain  points)  than  at  the  orifice. 
An  exception  to  this  rule  lies  in  such  cavities  as  are  of  small  diameter 
and  of  more  than  moderate  depth.  In  cavities  of  this  character, 
parallel  walls  will  suffice,  because  lateral-surface  contact  is  so  great  in 
proportion  to  the  mass  to  be  held  in  place  that  disi)lacemcnt  could  not 
occur.  In  larger  cavities  of  moderate  depth,  however,  the  reverse  is 
the  case,  and  they  will  require  the  assistance  of  internal  enlargement 
for  the  retention  of  the  filling.  To  govern  each  of  the  conditions  two 
rules  may  be  formulated  : 

1.  When  the  depth  of  the  cavity  is  greater  than  the  diameter  of  the 
orifice,  parallel  lateral  walls  will  prove  retentive. 

2.  When  the  diameter  of  the  orifice  is  greater  than  the  dejoth  of  the 
cavity,  the  latter  wall  have  to  be  somewhat  enlarged  internally  to  retain 
the  filling. 

Examples  of  the  first  class  are  found  in  the  narrow  but  rather  deep 
cavities  which  occur  on  the  lingual  surfaces  of  the  upper  incisors 
near  the  cervix  ;  in  the  pit  cavities  on  the  buccal  surfaces  of  molars ; 
and  in  the  small  cavities  found  on  either  side  of  the  enamel  ridge  on 
the  occlusal  surfaces  of  the  lower  first  bicuspids. 

Examples  of  the  second  class  are  found  in  numberless  places  on  any 
of  the  crown  surfaces. 

In  some  cases  cavities  will  be  found  of  such  form  that  when  the 
decay  has  been  removed  they  will  have  a  naturally  retentive  shape,  but 
in  the  great  majority  of  cases  more  or  less  sound  tissue  will  have  to  be 
removed  in  order  to  give  them  the  required  form.  To  give  a  cavity  a 
retentive  form  it  is  not  necessary  that  its  interior  be  enlarged  throughout 
its  whole  extent,  but  it  must  be  larger  at  two  or  more  points,  and  these 
points  must  be  opposite  one  another.  Frequently  it  will  be  easier  to 
enlarge  the  cavity  at  all  points,  and  to  this  no  objection  can  be  urged 
provided  too  much  sound  tissue  be  not  removed  or  the  pulp  be  not  too 
nearly  approached.  Too  great  enlargement  tends  to  weaken  the  cavity 
walls  and  therefore  should  be  guarded  against. 

In  shaping  the  cavity  internally  instruments  should  be  employed 
that  will  leave  the  surface  free  from  angles,  for  the  filling  material  can- 


SHAPING   THE  CAVITY. 


221 


not  be  perfectly  adapted  to  them.  As  in  the  removal  of  decay,  excava- 
tors for  this  purpose  should  have  curved  edges,  and  burs  should  be  of 
a  round  or  oval  form. 

If  grooves  are  required  they  should  neither  be  made  deep  nor  too 
near  to  the  enamel,  for  fear  of  weakening  the  walls.  At  the  cervical 
margins  of  cavities  grooves  and  starting  pits  should  be  avoided  when- 
ever possible,  for  they  weaken  the  portion  of  the  cavity  which  is  sub- 
jected to  the  greatest  strain  in  the  introduction  of  the  filling,  both 
mechanically  and  by  cutting  off  the  nutrient  supply  to  the  cervical 
margin,  which  tends  to  alter  the  resistive  character  of  that  portion  of 
the  tooth  structure  by  devitalizing  it. 

For  the  same  reasons  deep  grooves  or  undercuts  should  not  be  made 
near  the  incisal  or  occlusal  surfaces,  for  the  strain  of  mastication  will  be 
liable  to  result  in  fracture  of  the  wall  if  it  is  tluis  unduly  weakened. 

In  the  process  of  shaping  the  cavity  internally  the  enamel  margins 
will  naturally  be  assuming  their  proper  form,  but  the  final  part  of  the 
preparation  should  consist  in  giving  these  frail  portals  of  the  cavity 
very  careful  and  minute  attention. 

The  value  and  permanency  of  a  filling  will  largely  depend  upon  the 
strength  of  the  enamel  icalls  and  their  proper  preparation.  The  enamel 
cap  of  a  tooth  when  intact  is  exceedingly  strong  and  capable  of  resist- 
ing great  strain,  but  when  its  continuity  has  been  broken  by  caries  and 
it  is  left  unsupported  by  dentin  it  is  very  weak  and  brittle.  This  is 
readily  understood  when  we  remember  that  enamel  is  composed  of  an 
aggregation  of  enamel  rods  or  prisms  in  close  juxtaposition,  slightly 
joined  together  by  a  cementing  substance,  with  their  greater  diameters 
perpendicular  to  the  plane  of  the  surface  of  dentin  upon  which  they 

Fig.  IGS. 


Showing  enamel  structure. 


rest.  When  continuous,  these  rods  mutually  support  one  another  and  are 
thus  capable  of  resisting  great  strain  ;  but  when  a  lesion  has  occurred 
they  lose  support  on  the  adjoining  side  and  hence  are  easilv  separated 
in  the  direction  of  their  length.  Fig.  1G<S  (after  Black')  shows  this. 
^  Denial  Cosmos,  vol.  xxxiii.  p.  441. 


222  PREPARATION  OF  CAVITIES. 

condition  perfectly.     A  (Ictacheil  section  of  enamel  j)risnis  is  represented 
at  (/,  and  at  h  is  slu)\vn  a  portion  about  being  separated  by  a  chisel. 

This  will  explain  why  enamel  unsupported  by  dentin  should  not  be 
allowed  to  form  the  margin  of  a  cavity,  for  it  will  probably  either  be 
fractured  while  the  filling  is  being  introduced  or  afterward  in  mastication. 
On  all  convex  surfaces  of  a  tooth  the  enamel  rods  radiate  outwardly, 
and  by  forming  the  margins  of  a  cavity  on  these  lines  it  will  have  a 
slightly  flaring  or  trumpet-shaped  orifice,  which  will  not  only  afford  the 
greatest  strength  but  will  admit  of  a  Ix'tter  finish  being  given  to  the  edges 
of  the  filling.  In  many  cases  it  will  be  necessary  to  give  the  margins  of 
a  cavity  more  of  an  outward  bevel  than  would  be  obtained  by  simply 
followino-  the  cleavao-e  lines  of  the  enamel  rods.  This  can  be  secured 
by  cutting  away  the  outer  ends  of  the  enamel  rods  in  an  oblicpie  direc- 
tion as  shown  at  c  in  Fig.  168.  No  weakening  of  the  border  will  result 
in  such  cases,  inasmuch  as  the  shorter  rods  will  still  rest  upon  the 
dentin.  If,  however,  the  rods  were  cut  so  as  to  leave  only  their  outer 
ends  in  place,  as  shown  at  d,  they  would  have  no  substantial  support, 
and  would  be  liable  to  be  crushed  during  filling  or  afterward.  All 
cavity  margins  should  have  the  outward  bevel  to  a  greater  or  less 
extent  in  order  to  secure  the  best  and  most  permanent  results. 

In  cavities  upon  depressed  or  concave  surfaces  of  teeth  it  would  not 

Fig.  169  ^^  ^^  have  the  enamel  margins  formed  on  the  lines 

P   B  of  enamel  cleavage,  for  this  would  make  the  margin 

of  the  orifice  the  most  contracted  portion  and  result 

in  frail  marginal  edges.     Fig.  169,  representing  a 

cross  section  of  a  bicuspid  tooth  with  a  cavity  in  the 

,.      ^    , .  sulcus,  will  illustrate  this  point :  A  shows  the  cavitv 

Cross  section  of  a  bicus-  '  i 

pid    showing    treat-     orifice   prepared  on  the   lines  of  enamel   cleavage, 

ment  of  enamel  mar-  i        xi        i  •  xi,  i.  i  x'  i 

gins  of  cavity  in  the     ^^^^^  ^  ^'^^  dressing  across  the  outer  edges  of  enamel 
sulcus.  required  to  give  the  necessary  strength. 

It  may  therefore  be  laid  down  as  a  rule  that  to  secure  the  best  results 
the  line  of  a  cavity  wall  from  ivithin  outward  should  form  with  tlie  surface 
of  the  tooth  at  this  point  an  obtuse  angle. 

Beside  the  proper  shaping  of  a  cavity  margin  it  should  also  be  made 
as  smooth  as  possible.  In  accessible  cavities  upon  exposed  surfaces  of 
teeth  the  final  marginal  smoothing  or  finish  can  best  be  effected  by  the 
use  of  a  bur  shaped  somewhat  like  a  fissure  bur,  but  having  a  rounded 
end  and  being  simply  file-cut  upon  its  surface  instead  of  being  bladed. 
Such  a  one  is  shown  in  Fig.  170.  Its  sides  being  parallel,  no  rounding 
of  the  cavity  margins  can  occur  when  it  is  used  with  the  end  inside  of 
the  cavity.  Any  other  form  of  bur  with  a  short  head  would  unavoidably 
give  to  the  cavity  margin  either  a  concave  or  a  convex  surface,  both  of 
which  would  be  incorrect. 


CLASSIFICATION  OF  CAVITIES. 


223 


The  buccal,  lingual,  and  cervical  margins  of  a  compound  approximal 

cavity  should  never  be  finished  with  a  bur,  even  of  the  plug-finishing 

variety,    but  should    be    smoothed    with    suitable    chisels,   broad-faced 

excavators,  or  approximal  trimmers,  the  latter  being  shown  in  Fig.  171. 

Fig.  170.  Fig.  171. 


File-cut  enamel  finishing  bur. 


Approximal  trimmer. 


The  practice  of  finishing  cavity  margins  with  sand-paper  disks, 
Hindostan-stone  points,  or  wooden  points  charged  with  emery  powder  is 
very  objectionable,  as  they  are  almost  certain  to  give  to  the  margins  a 
rounded  edge  which  cannot  be  filled  and  finished  without  leaving  a 
feather  edge  of  tlie  filling  overlying  the  enamel,  which  will  eventually 
be  broken  oif  or  flared  up,  leaving  an  imperfect  margin. 

Classification  of  Cavities.' 
I.     Simple  Cavities  ox  Exposed  Surfaces. 
Bicuspids  and  Molars.  Incisors  and  Canines. 

A.  Occlusal.  D.  Labial. 

B.  Buccal.  E.  Lingual. 
C.  Lingual.  F.  Incisal. 

II.     Simple  Approximal  Cavities. 
Incisors  and  Canines.  Bicuspids  and  Molars. 

G.  Mesial  and  distal.  H.  Mesial  and  distal. 


Compound  Cavities. 

Bicuspids  and  Molars. 
P.  Mesio-occlusal. 
Q.  Disto-occlusal. 
R.  Occluso-buccal. 
S.  Occluso-lingual. 
T.  Mesio-disto-occlusal. 


III. 

Incisors  and  Canines. 

I.  Mesio-labial. 

/.  Disto-labial. 

K.  Mesio-lingual. 

L.  Disto-lingual. 

31.  Mesio-incisal. 

N.  Disto-incisal. 

0.  Mesio-disto-incisal. 

^  Following  the  sugsc^tion  of  Dr.   Black,  in  the  above  list  the  word  lingual  \9.  used 
for  the   same  surfaces  in  both  the  upper  and   lower  teeth,  doing  away  with  the  word 


224  PREPARATION   OF  CAVTTTES. 

In  the  foregoing  classification  the  cavities  have  been  arranged  pro- 
gressively from  the  simplest  (^1)  to  the  most  complicated  (7'). 

I.    Simple  Cavities  on  Exposed  Surfaces. 

HK'USPIDS    AND    MOLARS. 

Class  A. — Cavities  upon  the  ocdusal  surface  are  very  accessible  and 
in  l"ull  view,  enabling  the  operator  to  see  every  part  of  the  cavity  and 
affording  him  i)lenty  of  room  in  which  to  operate.  Naturally  those 
nearest  the  front,  as  in  the  bicuspids,  present  the  advantage  of  greater 
accessibility,  but  none  of  them  are  difficult  to  prepare  and  fill  except 
under  unusual  conditions. 

Usually  the  first  part  of  a  bicuspid  crown  to  become  affected  by 
caries  is  the  fissure  between  the  cusps.  Sometimes  it  presents  merely  as 
a  black  line  into  which  only  the  point  of  an  explorer  will  penetrate ; 
at  a  later  stage  the  cavity  is  more  fully  defined  by  the  greater  pro- 
gress of  caries  and  the  crumbling  of  the  walls  of  its  orifice.  In  the 
first  instance  the  cavity  is  most  readily  and  comfortably  o])cned  by 
means  of  the  tapering  fissure  bur  shown  in  Fig.  163.  After  passing  it 
into  one  of  the  terminal  pits  of  the  cavity  it  may  be  drawn  along  toward 
the  other,  opening  the  fissure  quite  freely.  Once  open,  the  decay  may 
be  removed  and  the  cavity  shaped  by  a  suitably  sized  round  bur 
(Fii^.  162).    As  the  decay  has  usually  progressed  farther  in  the  region 

of  the  terminations  of  the  cavity  than  in 
F^^- 1"^-  the  space  between  them,  the  cavity  when 

fully  formed  will  be  oblong  in  shape  and 
contracted  in  the  centre.  In  Fig.  172, 
A  shows  this  form,  while  B  represents 
the    same    surface  before   being  oiierated 

Cavity  in  sulcus  of  a  Viii'uspia.  ^ 

upon. 

In  preparing  the  cavity  no  more  sound  tooth-structure    should  be 

sacrificed  than  is  absolutely  necessary,  but  every  portion  of  decay  should 

Fig  173  ^^  thoroughly  removed  and  particular  attention  be  given 

to  opening  up  the  minor  fissure  terminations  as  shown  at 

A  a,  B  B  (Fig.  173). 

When    completed,  the    cavity  should  be  very  slightly 

larger   within  than    without,  the  margins    should  present 

^      no  angles,  but  only  a  series  of  curves  in  outline,  and  the 

The  fissure  07/ 

terminals.  marginal  edges  should  be  slightly  bevelled  outwardly. 
Bicuspid  cavities  of  this  character  vary  in  size  according  to  the  extent 
of  decay,  but  the  essential  features  in  each  case  are  very  similar.     The 

palatal.  In  the  forming  of  compound  terms,  where  the  mesial,  or  dintal  surfaces  are 
included,  these  terms  precede  the  others.  Where  they  are  not  included  and  the  word 
occlusal  is  used,   it  is  given  first  phice. 


SIMPLE  CAVITIES  ON  EXPOSED  SURFACES.  225 

lower  first  bicuspid  differs  normally  from  all  others  of  its  kind  in 
having  no  sulcus  and  consequently  no  fissure  between  the  cusps.  In- 
stead of  the  two  cusps  being  separated  by  a  sulcus  they  are  united  by 
a  ridge  of  enamel.  (See  Chap.  I.,  p.  35.)  The  only  points,  therefore, 
that  invite  decay  upon  the  occlusal  surface  of  this  tooth  are  the  two 
pits  that  are  found  one  on  each  side  of  the  ridge.  These  are  to  be 
filled  separately.  They  probably  represent  the  very  simplest  form  of 
simple  cavities  to  be  found  anvAyhere  in  teeth. 

The  occlusal  surface  of  an  upper  first  or  second  molar  presents  two 
points  liable  to  decay.  One  is  a  pit  formed  by  the  junction  of  two 
small  fissures  near  the  mesial  margin,  and  the  other  is  a  fissure  which 
runs  between  the  disto-buccal,  disto-lingual,  and  mesio-lingual  cusps. 
Both  are  represented  in  Fig.  174.  When  limited  in  extent  they  should 
be  opened  in  the  same  manner  as  a  bicuspid  fissure  cavity,  but  when 
larger  they  may  be  opened  by  means  of  a  chisel  followed  by  a  suitable 
bur.  In  these,  as  in  all  cavities  in  sulci,  the  fissures  must  be  followed 
and  opened  up  to  their  extremest  limits  in  order  to  ensure  success,  while 
the  margins  and  marj^inal  edges  must  be  so  formed  as  to  be  strong;, 
smooth,  and  bevelled. 

The  general  form  of  these  cavities  when  prepared  is  shown  in 
Fig.  175.      It  will  frequently  be  found  that  these  two  occlusal  cavities 

Fig.  174.  Fig.  175.  Fig.  176.  Fig.  177. 


Molar  fissure  cavities.  Molar  fissure  cavities  prepared  for  filling. 

are  joined  underneath,  while  near  the  surface  they  are  separated  by  a 
ridge  of  enamel  and  dentin.  In  such  cases  the  ridge  should  be  cut 
away  and  the  two  cavities  converted  into  a  single  larger  one  as  illus- 
trated in  Fig.  176. 

If  the  ridge  were  allowed  to  remain  it  would  almost  certainly  be 
fractured  either  in  the  operation  of  filling  or  subsequently  by  the  force 
of  mastication. 

The  upper  third  molar  differs  from  those  anterior  to  it  in  having 
but  three  cusps  and  consequently  but  one  central  pit  with  radiating 
fissures.  A  cavity  occurring  here  when  properly  prepared  will  pre- 
sent a  triangular  outline  with  rounded  angles,  as  in  Fig.  177.  The 
terminals  of  fissures  should  always  be  finally  finished  Avith  a  round  bur 
to  prevent  any  possible  angles  and  opportunity  for  leakage  at  those  points. 

The  lower  first  molar,  as  well  as  the  third,  having  five  cusps  with 
intervening  sulci,  a  cavity  ujion  this  surface  will  be  pentagonal  in  out- 
line, as  represented  in  Fig.  178. 

15 


226 


PREPARATION  OF  CAVVriES. 


Extreme  care  should  bo  exorcised  in  ])roparing  cavities  of  this 
character  to  insure  that  the  fissures  running  between  the  buccal  cusps 
are  fully  opened  and  cleared  of  every  particle  of  decay  and  discolora- 
tion.    Too  often  this  is  overlooked  and  caries  supervenes. 

The  lower  second  molar  with  its  four  cusps  has  two  sulci  inter- 
secting each  other  at  a  right  angle.  Decay  usually  begins  at  the  inter- 
section and  extends  along  the  radiating  arms  of  the  fissures.  If  the 
cavitv  wore  jireparcd  by  cutting  out  the  fissures  only  it  would  yield  a 
crucial-shaped  cavity  with  four  sharj)  or  nearly  sharp  angles  at  the 
intersection,  as  shown  in  Fig.  179.     Owing  to  those  angles  of  dentin 


Fig.  178. 


Fig.  179. 


Fk;.  180. 


Lower  first  molar  with  stel- 
late cavity.    Prepared. 


Lower  second  molar  with 
crucial  cavity.  Not  pro- 
perly prepared. 


Prepared    cavity    in    lower 
second  molar. 


and  enamel  the  perfect  filling  of  the  cavity  would  be  exceedingly 
difficult. 

The  case  may  be  simplified  and  better  results  in  every  way  obtained 
by  rounding  these  angles  and  giving  the  cavity  a  form  like  the  one 
shown  in  Fig.  180. 

Class  B. — Buccal  cavities  are  seldom  met  with  in  the  bicuspids 
except  at  the  cervix.  In  this  location  they  possess  the  same  features  as 
the  similar  class  of  cavities  occurrino;  on  the  labial  surfaces  of  the 
incisors.     Their  treatment  will  be  described  under  class  I). 

The  upper  molars  also  are  seldom  found  decayed  on  the  buccal  sur- 
face except  at  the  cervical  border.  Cavities  occurring  at  this  point  are 
usually  narrow  and  long,  following  the  outline  of  the  gum.  They  can 
best  be  prepared  with  an  engine  bur  of  suitable  form,  and  if  occurring 
on  the  second  and  third  molars  a  right-angle  attachment  may  have  to 
be  employed  to  reach  them  conveniently.  Decay  at  this  point  is  often 
of  the  white  variety,  and  as  it  so  nearly  resembles  the  natural  color 
of  the  tooth  extreme  care  will  have  to  be  exercised  to  include  all  of 
the  decalcified  portion  within  the  limits  of  the  cavity.  A  retentive 
form  is  most  conveniently  given  to  these  cavities  by  slightly  undercut- 
ting them  in  the  direction  of  their  length.  In  the  third  molars  it  is 
sometimes  advisable  to  make  an  undercut  or  starting-pit  at  the  distal 
end  for  the  beginning  of  the  filling. 

Sometimes  a  small  cavity  will  be  found  at  about  the  centre  of  the 
buccal  surface  of  the  upper  molars,  but  far  more  frequently  a  cavity 
of  greater  extent  will  be  found  upon  the  same  surface  of  the  lower 
second  molar.     It  originates  in  a  pit  at  the  termination  of  the  fissure 


SIMPLE  CAVITIES  ON  EXPOSED  SURFACES.  227 

running  over  from  the  occlusal  to  the  buccal  surface  between  the  two 
buccal  cusps.  Oftentimes  the  cavity  is  so  large  as  to  include  the  greater 
portion  of  this  surface  of  the  tooth.  Its  usual  form  and  appearance  are 
shown  in  Fig.  LSI. 

Not  infrequently  this  cavity  is  compounded  with  one  on  the  occlusal 
surface.     In  opening  and  preparing  it  a  slightly  undercut 
form  is  readily  given  to  it. 

Class  C. — Decay  rarely  occurs  upon  the  lingual  sur- 
faces of  molars  on  account  of  their  smoothness  and  con- 
vexity and  because  they  are  more  or  less  constantly  rubbed  gu^cai  cavitv 
by  the  tongue  in  speech  and  mastication.  The  evenness  of  i"  lower  sec- 
this  surface  is,  however,  broken  in  the  upper  first  and  sec- 
ond molars  by  a  fissure  extending  over  from  the  occlusal  surface  and 
passing  between  the  two  lingual  cusps.  (See  Chap.  I.,  p.  39.)  This  fis- 
sure is  deeper  and  more  pronounced  in  the  first  molar,  but  in  each  tooth 
it  is  generally  the  seat  of  caries  early  or  later  in  life.  In  the  majority 
of  cases  this  fissure  is  decayed  througliout  its  entire  length,  forming  a 
compound  cavity,  but  occasionally  only  the  pit  at  its  termination  on 
the  lingual  surface  is  affected. 

Another  point  on  the  lingual  surface  liable  to  decay  is  on  or  near  the 
mesio-lingual  angle  of  the  upper  first  molar,  about  midway  between  the 
cervical  and  occlusal  margins.  At  this  place  is  often  found  a  supple- 
mental cusp,  diminutive  in  size,  and  where  it  joins  the  main  surface  of 
the  tooth  a  small  fissure  exists  which  invites  decay.  This 
additional  cusp,  when  it  does  exist,  is  found  only  upon  the  ^^'  ■^^^■ 

first  molar.  It  is  shown  at  A  in  Fig.  182.  (See  Chap. 
I.,  p.  ol>.)  Neither  of  these  cavities  presents  any  diffi- 
culties in  preparation  except  such  as  occur  from  their  slight 
difficulty  of  access. 

Oecasionall}',  though  very  rarely,  the  lingual  surface 
of  any  of  the  molars  may  present  a  cavity  of  decay  close 
to  the  gingival  line  and  partly  beneath  it.  Such  cavities  are  doubtless 
caused  by  the  retention  of  food  debris  beneath  the  free  margin  of  the 
gum,  and  owing  to  their  position  they  are  difficult  to  treat.  They 
should  be  opened  and  packed  over-full  with  cotton  and  varnish  or 
gutta-percha  for  a  day  or  two,  to  press  the  gum  away,  after  wdiich  they 
may  be  prepared  and  filled  in  the  usual  manner. 

INCISOKS    AND    CANIXES. 

Class  D. — Cavities  upon  the  labial  surfaces  of  incisors  and  canines 
are  usually  found  along  the  gingival  margin,  and  are  the  result  of  the 
direct  action  of  acids  probably  formed  at  this  point.  In  the  beginning, 
and  when  small,  they  are  entirely  exposed,  but  when  of  greater  extent 


22<S  PREPARATION  OF  CAVITIES. 

they  frequently  extend  beneath  the  free  margin  of  tlie  gum.  Thoy  are 
nearly  always  elliptical  in  outline  and  may  consist  of  simple  decalcified 
enamel  still  retaining  the  usual  surface  form,  or  they  may  possess  the 
common  characteristics  of  cavities  in  general. 

The  opening  and  j)rcparation  of  this  class  of  cavities  are  not  attended 
with  any  marked  difficulties  except  that  when  they  extend  beneath  the 
gum  care  Avill  have  to  be  exercised  not  to  wound  this  tissue,  as  the 
consequent  bleeding  would  obstruct  the  view  and  interfere  with  the 
progress  of  the  work.  This  may  be  prevented  by  pressing  and  holding 
the  gum  away  with  a  suitable  instrument  held  in  the  left  hand  while  the 
cavity  is  being  prepared,  Particidar  attention  should  be  paid  to  the  care- 
ful })reparation  of  the  cervical  margin  of  the  cavity  and  to  its  terminal 
points.  The  former  should  be  made  smooth  and  even,  and  the  latter 
should  be  extended  far  enough  to  include  any  enamel  that  shows  the 
least  sign  of  acid  alteration.  Slight  grooves  or  enlargements  at  the 
base  of  the  cavity  along  its  upper  and  lower  margins  will  give  it  a  suf- 
ficiently retentive  form. 

A  second  locality  on  the  labial  surface  M'here  decay  is  frequently 
found  is  anywhere  between  the  central  portion  and  the  iucisal  edge, 
in  pits  and  depressions  that  indicate  imperfect  development  of  the 
enamel.  These  pits  or  grooves  extend  in  a  nearly  straight  line  parallel 
to  the  incisal  edge,  and  are  frequently  the  seat  of  decay. 

When  quite  shallow  they  may  be  obliterated  by  grinding  the  surface 
with  a  small  corundum  wheel  and  polishing,  converting  the 
surface  at  this  point  into  a  distinct  concavity.  When  the 
pits  are  deeper  and  isolated  they  may  be  filled  separately, 
the  result  being  a  lesser  degree  of  conspicuousness  ;  but 
when  they  are  connected  by  a  groove,  as  they  usually  are, 
Pitted  incisor.  thcY  will  havc  to  be  Converted  into  a  single  cavity  and 
filled.    A  common  type  of  this  defect  is  shown  in  Fig.  1 83. 

When  these  pits  occur  upon  the  incisal  edge  or  in  close  proximity 
to  it  the  choice  lies  between  an  unsightly  gold  filling,  a  porcelain  tip,  or 
their  removal  by  grinding  and  the  resultant  shortening  of  the  crown. 

Class  E. — There  is  usually  but  one  point  upon  the  Ungual  surface 
of  incisors  and  canines  that  is  liable  to  decay.  It  is  in  the  pit  at  the 
junction  of  the  basilar  ridge  or  cingulum  with  the  adjacent  tooth 
surface.  The  incipiency  of  caries  at  this  point  presents  only  as  a  mi- 
nute cavity,  the  opening  and  shaping  of  which  is  readily  accomplished 
with  a  round  bur.  Although  the  orifices  of  these  cavities  may  be 
small,  the  dark  spot  that  marks  their  direction  is  often  continued  quite 
a  distance  toward  the  pulp  chamber.  This  black  point  should  in  all 
cases  be  followed  to  its  termination  and  obliterated.  It  will  never  be 
found  to  reach  the  pulp  or  to  approach  dangerously  near  it.     As  the 


SniPLE  APPROXIMAL   CAVITIES.  229 

depth  of  these  cavities  is  greater  than  the  diameter  of  their  orifices,  no 
special  retentive  shape  need  be  given  them. 

The  orifice  shoukl  always  be  bevelled  and  enlarged,  if  necessary,  to 
include  any  neighboring  fissures. 

When  these  cavities  are  of  greater  extent  they  are  prepared  and 
filled  like  others  of  similar  size  and  form. 

Class  F, — Cavities  upon  and  confined  to  the  inched  edge  of  incisors 
and  canines  are  easily  prepared  on  account  of  their  accessibility.  This 
particular  surface  should,  and  generally  does,  remain  free  from  decay 
on  account  of  the  attrition  to  which  it  is  constantly  subjected  ;  but 
when  defects  in  the  enamel  exist,  caries  sometimes  occurs  in  connection 
v/ith  it. 

This  surface  often  needs  covering  with  gold  to  check  abrasion  in 
cases  Avhere,  after  middle  life,  the  crowns  (especially  those 
of  the  upper  teeth)  have  been  shortened  by  excessive 
wear.  Under  these  conditions  the  surface  has  to  be  so 
prepared  and  shaped  as  to  retain  the  gold  that  is  to  cover 
and  protect  it  just  as  though  caries  had  originally  injured 
the  part.  In  forming  the  cavity  in  the  exposed  dentin 
it  is  only  necessary  to  cut  deeply  enough  to  aiford  a  lodg- 
ment for  the  filling,  but  the  orifice  must  be  so  enlarged  and  ^ross  section  of 
excessively  bevelled  as  to  reach  to  the  marginal  edge  of  cavity  on  in- 
enamel  all  around.  This  is  done  to  protect  the  enamel 
from  chipping  or  fracture  in  mastication.  To  aiford  the  greatest 
security  to  the  filling  the  cavity  should  be  undercut  throughout  its 
whole  extent.  When  thus  prepared,  the  cavity  in  cross  section  will 
resemble  a  double  dove-tail  as  shown  in  Fiff.  184, 


II.    Simple  Approximal  Cavities. 

INCISORS    AND    CANINES. 

Class  G. — Cavities  upon  the  mesial  and  distal  surfaces  of  the 
anterior  teeth  present  only  the  difficulty  arising  from  inaccessibility. 
To  reach  and  operate  upon  these  cavities,  the  teeth,  if  in  normal  contact, 
will  usually  have  to  l)e  }>ressed  apart  either  by  gradual  wedging  or  by 
immediate  separation  with  a  "  separator."  Even  after  this  has  been 
accomplished  the  cavity  cannot  be  operated  upon  in  a  direct  way  as  are 
cavities  upon  exposed  surfaces,  but  will  have  to  be  approached  from 
either  the  labial  or  lingual  aspect  of  the  crown.  To  do  this,  if  the 
cavity  be  small,  will  generally  necessitate  an  additional  enlargement  of 
the  cavity  toward  the  surface  from  which  it  is  to  be  approached.  As 
the  lesser  of  two  evils  the  enlargement  is  usually  made  toward  the 
lingual  surface,  for  in  this  way  the  exposure  of  gold  when  the  filling  is 


230  PliEPAEATIOX  OF  CAVITIES. 

completed  will  not  he  noticeable.     When  the  cavity  is  of  larger  size  and 

the  enamel  wall  on  the  labial  surface  has  Ixmmi  weakened  by  caries  it  will 

have  to  be  removed,  and  access  will  thus  unavoidably  be  afforded  from 

that    side.     Whenever    possible,   however,  undue    eularo-enient  of   the 

cavity  and  consequent  exposure  of  gold  should  be  avoided. 

In   ordinary  cavities   upon   the   approximal  surface  the   frail   walls 

T^      ,o^  borderino-  the   orifice    should   be   broken   awav  with 

hm.  185.  .  . 

a  small  chisel,  and  after  the  decay  has  been   removed 

by  means  of  burs  or  excavators  and  the  proper  form 

given  to  the  cavity,  the  margins  should  l)e  carei'ully 

smoothed  and  bevelled  with  small  plug-finisiiing  burs 

or  with    the    side-cutting    edge    of  the   small    chisel 

shown  in  Fig.  166  and  here  reproduced  (Fig.  185). 

Anchorage  is  obtained  in  these  cavities  by  slightly 

deepening  the  cavity  at  its  cervical  termination  and 

making  a  shallow  undercut   in  the  dentin  near  the 

incisal  border.     Retaining  grooves  should  never  be 

Delicate    three-sided     made  in  the  labial  or  lingual  walls  of  the  cavities, 

chisel,   useful    lor  ^^       would  scriously  Weaken  them.     In  apijroxi- 

openmg  cavities  on  -  •'  '^  ^ 

approximal  sur-  mal  cavitics  of  large  size  where  they  extend  from 
near  the  incisal  edge  to  or  beyond  the  free  margins 
of  the  gum,  the  difficulties  of  producing  a  perfectly  formed  cavity 
are  greatly  increased.  While  affording  greater  ease  of  approach  on 
account  of  their  size,  the  cervical  border  of  this  class  of  cavities  is 
apt  to  be  less  perfectly  prepared  owning  to  its  obscure  location.  When 
the  cervical  border  extends  beneath  the  free  margin  of  the  gum  the  latter 
should  be  pressed  and  held  away  during  excavating,  so  that  the  cervical 
wall  may  be  plainly  seen  and  operated  upon  throughout  its  whole 
extent. 

Cutting  of  the  wall  should  be  sufficiently  extended  rootward  to  in- 
clude any  defects  or  checks  in  the  enamel  bordering  it,  and  should  be 
made  entirely  smooth  and  free  from  angles,  for  it  is  the  most  vulnerable 
border  of  the  cavity  after  the  filling  has  been  completed.  Should  the 
cavity  extend  to  near  the  enamel  terminatic^i  at  the  cervix,  it  will  be 
best  to  still  further  extend  it  so  as  to  pass  beyond  this  margin  ;  for  if  a 
small  portion  of  enamel  be  left  there  it  will  be  lial)le  to  be  broken 
aAvay  in  the  process  of  filling  and  thus  seriously  impair  the  junction  of 
the  filling  with  the  border. 

So,  also,  if  the  cavity  on  account  of  its  size  should  approach  very 
near  to  the  incisal  edge,  it  is  best  to  remove  this  frail  corner  and  con- 
vert the  cavity  into  a  compound  one.  Where  such  a  weak  corner  is 
allowed  to  remain  it  is  very  frequently  broken  away  in  subsequent  mas- 
tication.    Such  a  result  is  shown  in  Fig.  186.     An  accident  like  this  is 


0 


SIMPLE  APPROXIMAL   CAVITIES.  231 

more  likely  to  oecur  in  thin,  flat  teeth  where  the  plates  of  enamel  meet- 
ing at  the  incisal  edge  have  little  or  no  dentin  between  them. 

Where  doubt  exists  as  to  whether  the  corner  should  be    p      ,gg 
removed  or  allowed  to  remain,  it  is  well,  after  the  cavity  has 
been  prepared,  to  test  the  strength  of  the  corner  by  strong  pres- 
sure upon  it  in  the  direction  of  the  long  axis  of  the  tooth  with 
a  piece  of  orange-wood.     If  it  resists  this  strain  it  will   prob-      straight 
ably  resist  the  force  of  mastication,  and  if  it  break  away  under     fracture. 
the  test  it  w^ill  demonstrate  that  it  would  have  been  unwise  to  allow  it 
to  remain. 

If  the  corner  be  left  as  a  border  and  support  for  the  filling  it  should 
not  be  weakened  by  a  deep  retaining  groove.  Such  groove  or  anchorage 
should  be  shallow,  and  as  far  removed  from  the  incisal  border  as  the 
conditions  will  permit. 

In  many  cases,  where  the  incisal  wall  would  be  seriously  weakened 
by  any  attempt  to  use  it  as  an  anchorage  or  support  for  the 
filling,  and  where  it  seems  undesirable  to  remove  it,  an  ex- 
cellent anchorage  for  the  lower  border  of  the  filling  may  be 
obtained  by  cutting  an  extension  upon  the  lingual  surface  in 
the  form  of  an  arm,  as  shown  in  Fig.  187.^  Such  extension, 
if  made  but  little  deeper  than  the  enamel,  will  not  materially 
weaken  the  tooth  and  will  secure  the  filling  perfectly. 

Its   position  should  be  near  the  incisal  edge,  but  not  so 
close  to  it  as  to  weaken  the  part. 

In  the  anterior  teeth  the  relative  difficulties  between  mesial  and  distal 
cavities  are  insignificant. 

BICUSPIDS    AND    MOLAES. 

Class  H. — The  preparation  of  small  cavities  on  the  mesial  and 
distal  surfaces  of  the  bicuspids  and  molars,  though  simple  in  character, 
is  usually  most  difficult  of  thorough  performance.  This  is  due  entirely 
to  their  inaccessibility  when  the  teeth  are  closely  approximated.  How 
to  approach  these  cavities  is  often  a  matter  of  no  small  concern  to  the 
student  or  young  practitioner,  and  the  preparation  and  filling  of  them 
is  generally  more  difficult  than  that  of  larger  and  more  complicated 
cavities  in  exposed  situations.  To  lessen  the  difficulty  of  approach  it  is 
important,  whenever  practicable,  to  create  by  wedging  beforehand  as 
great  a  separation  as  jiossible  between  the  teeth.  The  greater  the  space 
gained  the  less  the  difficulty  of  approach. 

When  conditions  will  not  warrant  cutting  doM  n  to  them  from  the 
occlusal  surface,  and  thus  converting  them  into  compound  cavities, 
but  two  ways  of  approach  are  left  open  :  one  is  from  the  direction  of 
'  Dental  Review,  vol.  ix.  pp.  812  and  819. 


232 


rnEPARATION  OF  CAVITIES. 


the  occlusal  surface,  and  the  other  from  the  buccal  aspect.  Usually  the 
former  is  chosen,  as  it  involves  less  sacrifice  of  tooth  structure,  although 
by  it  the  difficulties  are  increased  owing  to  the  limited  space  in  which 
we  arc  obliged  to  operate. 

These  cavities  can  usually  be  best  opened  and  mainly  ])reparcd  with 
a  round  bur.  After  the  decay  has  been  removed  and  the  walls  defined 
and  prepared,  the  cavity  may  be  made  retentive  in  form  by  sli<>ht  under- 
cutting throughout  its  entire  circumference,  or  it  may  be  enlarged  at 
two  o[)posite  })oints  only.  The  cervical  wall  can  be  inwardly  deepened 
by  an  obtuse-angle  hatchet  excavator  as  illustrated  in  Fig.  188,  and  the 
lower  or  occlusal  wall  be  slightly  imdercut  by  an  acute-angle  excavator 
like  Fiff.  189. 


Fig.  188. 


Fig.  189. 


Obtuse-angle  hatchets. 


Acute-aiiKle  hatcliets. 


The  sharp  angles  on  the  cutting  edges  of  these  excavators  should 
be  rounded  before  being  used,  so  as  to  avoid  the  formation  of  angles  in 
the  cavity. 

As  the  enamel  rods  on  this  surface  radiate  outwardly  at  such  an 
angle  as  to  give  the  proper  bevel  to  the  orifice  of  the  cavity,  a  careful 
following  of  their  lines  in  the  preparation  of  the  cavity  margins  will 
be  all  that  is  necessary  to  give  them  the  desired  form  and  strength. 

Occasionally  these  cavities,  instead  of  being  round  or  nearly  so,  have 
a  decided  oval  or  oblong  form,  their  greater  diameter  being  in  a  bucco- 
lingual  direction,  in  which  event  the  cavity  may  generally  be  best  ap- 
proached, for  preparation  and  filling,  from  the  buccal  aspect. 

When  this  seems  desirable,  the  cavity  should  be  extended  so  as  to 
open  at  the  approximo-buccal  angle.  A  round  bur  is  best  suited  for 
this  purpose,  and  when  the  extension  has  thus  been  made  the  cervical 
and  occlusal  walls  of  the  cavity  may  be  slightly  grooved  with  a  hoe 
excavator  and  the  inner  or  lingual  wall  be  made  abrupt  and  also  slightly 
undercut. 

In  all  cases  where  sufficient  space  cannot  be  gained  to  operate  satis- 
factorily from  the  direction  of  the  occlusal  surface,  an  extension  of  the 
cavity  to  the  buccal  aspect  is  the  only  alternative. 


COMPOUND   CAVITIES.  233 

Where  simple  cavities  upon  the  approximal  surface  are  large  they 
may  extend  so  near  to  the  occlusal  surface  as  to  weaken  it.  When  this 
is  the  case  the  enamel  wall  should  be  cut  away  and  the  cavity  converted 
into  a  compound  one  of  the  approximo-occlusal  type. 

III.    Compound  Cavities. 

INCISORS   AND    CANINES. 

Classes  /  and  /. — Mesio-lahial  and  disto-Iabial  cavities  occur  from 
the  near  approach  or  union  of  simple  cavities  upon  their 
respective  surfaces.  Cavities  of  considerable  length  up- 
on the  approximal  and  labial  surfaces  are  very  apt  to 
join  one  another  by  extension  of  caries.  When  they 
do  not  join  they  are  usually  separated  by  a  narrow  terri- 
tory of  more  or  less  impaired  tooth  tissue,  and  in  such  Mesio-iabiai  cav- 
cases  must  be  united  to  obtain  a  satisfactory  result.  Each 
cavity  should  be  as  nearly  prepared  as  possible  separately,  after  which 
the  intervening  tissue  should  be  cut  away  and  the  lines  of  the  channel 
connecting  the  two  be  made  as  strong  and  smooth  as  possible.  This 
channel  will  usually  be  of  less  width  than  either  of  the  cavities,  but  not 
more  difficult  to  fill  on  this  account.  Fig.  190  shows  a  front  view  of 
such  a  compound  cavity. 

Whether  the  cavity  be  a  mesio-labial  or  a  disto-labial  one  will  not 
materially  affect  the  manner  or  difficulty  of  operating. 

Classes  K  and  L. — Jlesio-Iingual  and  disto-Iingual  cavities   are 
formed  in  the  same  manner  as  those  of  classes  /  and  J  except  that  in 
these  cases  the  lingual  surface  is  involved  instead  of  the  labial.    ^      .^i 
Extensive  caries  in  the  region  of  the  basilar  pit  or  of  the 
fissures    connected  with  it  often  approaches  so  nearly  to  an 
approximal  cavity  in  the  same  tooth  as  to  demand  the  union 
of  the  two   (see  Fig.   191).      The  method  of  preparing  and 
uniting  the  two  is  substantially  the  same  as  that  followed  in 
classes  /  and  J,  just  described. 

A  mesio-lingual  cavity  is  perhaps  more  easily  prepared  and  filled 
than  a  mesio-labial  one,  for  in  its  preparation  the  free  cutting  away 
of  the  intervening  wall  is  permissible,  which  affords  increased  room  for 
operating. 

Fortunately,  a  lingual  cavity  rarely  extends  so  far  as  to  connect  with 
both  a  mesial  and  a  distal  cavity.  When  it  does,  the  joining  of  the 
three  cavities  very  seriously  weakens  the  crown  at  the  point  where  the 
greatest  strain  occurs. 

Classes  J/ and  X. — These  classes  include  cavities  upon  either  the 
mesial  or  distal  surfaces  connecting  with  a  cavity  upon  the  incisal  edge. 


234  PRPJPARATIOy  OF  CAVITIES. 

They  usually  oeoiir  in  oonsequenco  of  the  wearing  away  of  the  latter 
surface  tlirouoh  attrition  or  from  the  necessitated  removal  of  the  incisal 
corner  on  aeeonnt  of  weakness,  Botli  the  a|)])roximal  and  incisal  cavi- 
ties mav  be  prepared  sei)arately  as  described  in  classes  i*' and  (r,  after 
which  they  should  be  connected,  the  walls  made  strong  and  smooth  and 
properly  bevelled. 

Atypical  cavity  of  tliis  class  is  siiown   in  Fig.    192.      In  all  such 
cases  the  labial  ])late  of  enamel  shonld  be  preserved  intact  as 
far  as  possible  for  appearance  sake,  and  if  any  cutting  has  to 
be  done  to  increase  the  size  or  depth  of  the  incisal  portion  of 
the  cavity,  it  should  be  done  at  the  expense  of  the  lingual  wall. 
In  order  to  protect  the  labial  wall  from  possible  fracture  in 
mastication  the  enamel  should  be  bevelled  outwardly  (as  men- 
tioned under  class  F)  so  that  when  filled  the  gold  alone  will 
come  in  contact  with  the  opposing  teeth  in  mastication. 
The  only  anchorage   needed   for  tins   class   of  cavities   is  a   slight 
undercut  along  the  cervical  wall  and  a  dovetailed  form  of  the  incisal 
portion  of  the  cavity. 

In  many  cases  there  is  no  cavity  upon  the  incisal  edge,  but  where 
opportunity  offers  for  making  one  (as  in  the  case  of  thick  or  worn  teeth) 
this  method  of  forming  a  compound  cavity  affords  the  greatest  possible 
support  and  security  for  a  large  ai)proximal  filling  involving  the  ap- 
proximo-incisal  angle. 

Where  the  crown  is  thin  and  unworn  upon  the  incisal  surface  a  com- 
pound cavity  of  this  character  cannot  be  formed,  but  the  same  result  as 
to  anchorage  may  be  obtained  by  cutting  an  extension  upon  the  lingual 
surface  of  suitable  size,  form,  and  depth,  as  described  on 
^^'     '^'         p.  231.     One  form  of  such  extension  where  the  corner  is 
gone  is  shown  in  Fig.  187.^     Another  form,  rej)resented 
in  Fis;.  193,'"^  consists  of  giving  the  extension  a  cnrved  or 
hooked  form.     Both  forms  serve  the  same  purpose,  for 
"^t-inauchoraT      ^^^^y  ^ff'^^'^l  in  these  cases  ])erfectly  secure  anchorage  which 
could  not  be  obtained  so  well  in  any  other  way. 
Class  0. — Mcdo-clkto-indsal  Cavities. — Cavities  of  this   character 
differ  from  the  preceding  ones  principally  in  extent.     The  method  of 
preparation    in    each  case   is    similar   and  the    operation   requires   the 
exercise  of  great  skill  and  care  in  order  to  produce  the  best  results. 
In  both  cases  the  following  points  will  have  to  be  observed  : 

As  the  operations  are  extensive  in  character,  good  strong  walls  are 
needed  on  all  sides  to  withstand  the  force  exerted  in  the  introduction  of 
the  filling. 

'  Dental  Review,  vol.  ix.  pp.  812  and  819. 

*  I.  C.  St.  John,  D.  D.  S.,  Dental  Cosmoss,  vol.  xxxvi.  p.  198. 


COMPOUND   CAVITIES.  235 

All  margins  must  be  smooth  and  nicely  bevelled. 

No  angles  or  checked  enamel  must  exist  along  the  borders. 

All  enamel  should  be  supported  by  underlying  dentin,  although 
to  avoid  the  exposure  of  gold  the  labial  plate  (whicli  is  thicker  than 
the  lingual)  may  sometimes  be  left  thus  unsupported  for  a  short  distance 
along  the  approximal  and  ineisal  margins. 

No  deep  anchorages  will  be  required.  Oidy  slight  ones  are  needed 
to  start  the  filling  at  the  cervical  wall,  for  the  form  of  the  filling,  when 
completed,  will  be  such  as  to  aiford  the  greatest  possible  security. 

BICUSPIDS    AND    MOLARS. 

Class  P. — Jlesio-occlasal  cavities  in  bicuspids  and  molars  represent 
a  class  not  only  frequently  met  with  and  difficult  to  fill,  but  one  also  in 
which  a  large  proportion  of  fillings  fail.  This  is  largely  due  to  the 
improper  shaping  of  the  cavity  and  the  imperfect  placing  and  adaptation 
of  the  fillino-.  When  these  cavities  are  of  moderate  size,  not  extendinsr 
as  far  as  the  gingival  margin  on  the  mesial  surfixce  and  without  any 
great  width  in  a  buccal  or  lingual  direction,  the  preparation  and  filling 
of  them  is  iK^t  attended  with  any  great  difficulty  ;  but  where  they 
extend  beneath  the  gum  margin  and  are  much  spread  out  laterally  they 
present  complications  that  are  difficult  to  overcome. 

The  cervical  margin  of  such  cavities  as  extend  only  to  or  near  to 
the  free  margin  of  the  gum  has  been  aptly  styled  the  "  vulnerable 
point,"  because  when  failure  occurs  in  these  fillings  it  usually  begins  at 
this  margin.  When,  however,  the  cavity  wall  extends  beneath  the  gum 
margin,  although  the  difficulties  of  operating  are  increased,  recurrence 
of  decay  is  seldom  met  with,  because  the  conditions  favorable  to  decay 
are  not  present  there. 

In  the  preparation  of  these  cavities  the  teeth  should  have  been  pre- 
viously wedged  in  order  to  affi:)rd  light  and  room  for  excavating,  as  well 
as  for  the  subsequent  introduction  and  finishing  of  the  filling.  If  the 
cavity  extend  beneath  the  margin  of  the  gum  the  hitter  should  be 
pressed  away  by  packing  the  cavity  over-full  with  gutta-percha  for  a 
day  or  two  previously. 

After  opening  and  roughly  preparing  the  cavity  the  rubber  dam 
should  be  adjusted  and  the  cavity  thoroughly  dried,  after  which  the  prep- 
aration can  be  completed  more  satisfactorily,  as  the  dryness  of  the  tooth 
will  enable  the  operator  to  readily  distinguish  between  sound  and  un- 
sound tissue. 

Whether  the  cavity  be  of  large  or  moderate  size,  simple  or  difficult 
in  character,  the  niceties  of  preparation  must  receive  due  consideration. 
The  cervical  portion  of  the  cavity  should  be  dressed  until  a  strong 
sound  wall  is  obtained.     In  it  there  must  be  no  angles,  and  bordering 


236 


rUEPARATION   OF  CAVITIES. 


Fig.  194. 


it  there  must  be  no  dccaloitied  tooth  structure  and  no  checks  in  the 
enamel.  Shoukl  either  of  the  latter  he  found,  further  cutting  of  the 
wall  will  be  necessary  until  these  defects  are  entirely  obliterated. 

If  the  cavity  should  extend  rootward  to  near  the  termination  of 
the  enamel,  it  wall  be  necessary  to  deepen  the  cavity  so  as  to  include 
this  portion,  otherwise  injury  will  be  liable  to  result  from  the  fracture 
of  this  frail  section  of  enamel  during  filling. 

The  outline  of  the  cervical  wall  may  be  either  distinctly  curved  or 
more  or  less  flattened  ;  the  latter  form,  shown  in 
Fig.  194,  A,  being  preferred  by  many  on  account 
of  the  assistance  it  renders  in  filling.  The  buc- 
cal and  lingual  walls  must  be  dressed  to  a  smooth 
outline  and  bevelled,  and  where  the  size  of  the 
cavity  warrants  it  should  be  extended  so  far 
toward  the  buccal  and  lingual  surfaces  as  to  free  them  from  the  danger 
of  future  decay.  In  Fig.  195  the  dark  portion  represents  the  buccal 
aspect  of  the  completed  filling.  None  of  these  walls  should  be  deeply 
undercut  to  assist  in  either  the  introduction  or  retention  of  the  filling, 
for  such  undercutting  is  a  source  of  weakness,  but  shallow  grooves  are 
not  objectionable  when  needed. 

Starting  pits  or  grooves  should  not  be  made  in  the  cervical  wall 
exce])t  in  rare  cases ;  a  slight  dipping  inward  of  the  wall,  as  indicated 
at  A,  Fig.  196,  being  sufficient  to  furnish  all  the  retentive  form  needed 
at  this  part  of  the  cavity. 

That  portion  of  the  cavity  in  the  sulcus  on  the  occlusal  surface  may 

Fig.  196.  Fig.  197. 


B     C 

(After  Black.) 


Prepared  cavities  and  anchorages. 

be  made  retentive  either  by  slightly  enlarging  it  inwardly  or  by  widen- 
ing it  at  its  termination,  as  shown  at  A,  Fig.  196.  Where  the  occlusal 
and  approximal  portions  of  the  cavity  meet,  the  angles  should  be  re- 
moved and  the  cavity  well  opened  so  as  to  afford  access  and  give 
strength  to  the  filling  (b,  Fig.  197). 

Fig.  198  represents  a  compound  cavity  of  this  class,  incorrectly 
formed.  In  it  moderately  sharp  angles  are  seen  at  the  points 
where  the  occlusal  and  approximal  portions  of  the  cavity  join. 
In  very  exceptional  cases,  cavities  upon  the  approximal  sur- 
faces that  involve  a  slight  portion  of  the  occlusal  do  not  need 
to  be  extended  along  and  include  the  sulcus  or  sulci  on  this 
surface,  owing  to  the  fact  that  no  fissures  and  no  decay  exist  in  them. 


Fig.  198. 


COMPOUND   CAVITIES. 


237 


In  such  instances  the  occlusal  portion  of  the  cavity  should  have  a  V 
shape  as  shown  in  Fig.  199,  and  anchorage  for  the  filling  at  this  point 
be  obtained  by  slightly  undercutting  the  approximo-occlusal  walls  at  a 
and  B. 


Fig 


Fig 


Fig.  201. 


sB  B  ^D 

Prepared  cavities  and  anchorages. 

In  the  diagram  Fig.  200  the  black  portion  represents  the  floor 
of  the  cavity ;  A  and  b  indicate  the  points  to  which  the  buccal  and  lin- 
gual walls  should  be  cut ;  C  and  d  show  the  curved  form  of  cavity 
after  the  occluso-approximal  angles  have  been  removed,  while  the 
curved  line  outside  of  the  cavity  indicates  the  approximal  contour  of 
filling,  with  contact  point  at  H. 

Fig.  201  represents  a  compound  cavity  (mesio-occlusal)  in  a  lower 
second  molar.  These  cavities  differ  from  similar  ones  in 
bicuspids  principally  in  having  the  occlusal  portion  of 
the  cavity  exteud  in  different  directions  along  the  sulci. 
All  of  the  terminations  should  be  ^vell  rounded  and  in 
no  portion  of  the  cavity  should  distinct  angles  be  allowed  Mesio-occiusai  cav- 

'    i  •'  o  ity  m  lower  sec- 

tO  remain.  ond  molar.    Pre- 

Class  Q. — Disto-ocdusal  cavities  in  either  the  bicus-     ^^"^^ 
pids  or  molars  are  not  essentially  different  from  mesio-occlusal  cavities 
in  the  same  teeth.      Owing  to  their  position   they  are  more    difficult 
of  approach,  but  their  manner  of  preparation  and  their  form  are  vir- 
tually the  same. 

Class  R. —  Occluso-buccal  cavities  are  more  frequently  met  with 
in  the  lower  than  in  the  upper  molars.  This  is  due  to  the  general 
presence  of  a  pit  upon  the  buccal  surface  in  which  decay  by  extension 
reaches  so  near  to  the  occlusal  surface  that  the  occluso- 
buccal  wall  is  weakened  and  has  to  be  removed.  Coin- 
cident with  this  there  is  usually  a  cavity  of  some  size 
upon  the  occlusal  surface,  and  the  union  of  the  two 
cavities  becomes  necessary  to  insure  a  satisfactory 
result  in  filling  them.  A  common  type  of  such  cav- 
ity is  shown  in  Fig.  202. 

The  channel  connecting  the  two   cavities  is  usually 
narrower  than  either  of  the  latter,  and  also  more  shallow, 
thus  conserving  the  strength  of  the  tooth.     As,  however,  the  strain 
upon  the  walls  bordering  this  channel  is  very  great  in  mastication  they 


Fig.  202. 


Occluso-buccal  cav- 
ity in  lower  molar. 
Prepared. 


238 


PREPARATION  OF  CAVPriES. 


Fig.  203. 


should  1)0  trimmed  until  solidity  is  obtainod,  and   also  ho  ronsidorably 
bovoUod  Ini'  purposes  of  strou<2;tli. 

Class  *S'. —  Orchtso-HiKjiKil  cavities  in  the  bicuspids  and  molars  are 
of  rare  occurrence  except  in  the  u])per  first  and  second  molars,  where 
they  follow  the  line  of  the  sulcus  extendino;  between  the  mesio-lingual 
and  disto-lingual  lobes.  Sometimes  the  cavity  is  nearly  confined  to  the 
oeclu.sal  surface,  running  over  on  to  the  lingual  surface  l)ut  slightly. 
In  such  cases  the  cavity  is  easily  prepared  by  simply  cutting  the  occlusal 
cavity  through  to  the  lingual  surface,  giving  the  cavity  a  relatively  uni- 
form depth  at  all  points. 

At  other  times  the  fissure  on  the  lingual  surface  will  extend  farther 
toward  the  cervical  margin,  and  the  cavity  when  prepared 
will  have  the  form  of  an  L,  the  longer  arm,  a,  represent- 
ing the  occlusal,  and  the  shorter  one,   b,  the  lingual  por- 
tion of  the  cavity  (see  Fig.  203).     Where  the  extent  of 
decay  does  not  demand  it,  it  would  1)0  a  mistake  to  make 
the  floor  level  of  the  two  portions  of  the  cavity  uniform, 
as  the  extensive  removal  of  sound  dentin  would  greatly 
weaken  the  disto-occluso-lingual  cusp. 
Where  extensive  decay  has  already  weakened  this  cusp  it  is  better  to 
amputate  it  below  the  level  of  the  occlusal  plane  and  extend  the  filling 
over  it. 

Class  T. — With  the  exception  of  those  unusual  cavities  which 
involve  the  greater  portion  of  the  crown  of  a  tooth,  the  mesio-diMo- 
occlusal  cavities  in  bicuspids  and  molars  are  the  largest  in  extent  of  any 
met  with.  Being  well  exposed  there  is  no  lack  of 
either  light  or  room  in  which  to  o])erate,  and  the  only 
difficidty  associated  with  their  preparation  and  filling 
lies  in  their  size  and  extent. 

Their  preparation  is  accomplished  in  the  same  man- 
ner as  those  of  classes  P  and  Q,  except  that  no  special 
retentive  form  need  be  given  to  the  occlusal  portion, 
for  with  the  filling  once  in  place  its  general  form  will 
secure  it  in  position.  Fig.  204  represents  a  typical  cavity  of  this  class 
in  a  bicuspid  tooth. 


Fig.  204. 


CHAPTER   IX. 

EXCLUSION  OF  MOISTURE— EJECTION  OF  THE  SALIVA- 
APPLICATION  OF  THE  DAM  IN  SIMPLE  CASES,  AND 
IN  SPECIAL  CASES  PRESENTING  DIFFICULT  COMPLI- 
CATIONS—NAPKINS AND  OTHER  METHODS  FOR  SECUR- 
ING DRYNESS. 

By  Louis  Jack,  D.  D.  S. 


The  interference  of  the  secretions  of  the  mouth  offers  a  considerable 


Fig.  206. 


Fig.  205. 


obstacle  to  the  treatment  of  the  teeth.  In  some  in- 
stances the  flow  is  naturally  excessive,  and  in  all  cases 
it  is  stimulated  by  the  operative  procedures. 

An  excessive  flow  of  saliva  is  uncomfortable  to  the 
patient ;  its  accumulation  also  impedes  the  operation, 
and  interferes  with  the  view  of  parts  by  refracting 
the  rays  of  light. 

During  the  preparation  of  accessible  cavities,  par- 
ticularly those  of  the  upper  front  teeth  and  the  occlusal 
surfaces,  the  accumulation  may  be  carried  ofi'  by  the  use 
of  a  SALIVA  EJECTOR,  a  simple  form  of  which  is  shown 
in  Fig.  205,  which  form,  or  some  modification  of  it,  is 
used  where  a  connection  can  be 
made  with  the  water  supply,  and 
ordinarily  it  is  used  in  association 
with  the  fountain  cuspidors.  An- 
other form,  which  is  connected 
with  a  small  reservoir  of  water, 
is  shown  in  Fisr.  206.  Either 
of  these  forms  has  a  further  use 
for  drawing  off  the  saliva  in  con- 
nection with  the  employment  of 
the  rubber  dam  to  lessen  the  dis- 
comfort of  the  patient. 


Use  of  Rubber  Dam. 

During  the  preparation  of  cavi- 
ties on  the  approximal  surfaces  of 
the  bicuspids    and  molars   where    it    is  essential    to    have   unrestricted 

239 


240  EXCLUSION  OF  MOISTURE. 

view  and  the  exclusion  of  blood,  the  presence  of  which  is  inse]):irable 
from  thor()ii<j;li  preparation  of  the  cerv^ical  margins,  it  is  necessary  to 
make  nse  of  tlie  rubber  dam.  When  used  for  this  purj)ose  the 
material  generally  becomes  impaired  by  the  action  of  the  instruments 
in  their  free  use  at  the  cervix  ;  but  the  economy  of  time  and  the  essen- 
tials of  thorough  performance  of  this  class  of  operations  warrant  the 
application  during  this  portion  of  the  treatment. 

When  the  case  is  ready  for  the  filling  process  a  new  piece  of  the  dam 
should  be  prepared,  and  adjusted  with  great  care  to  prevent  the  ingress 
of  the  least  moisture.  Without  this  appliance  the  greatest  skill  is  pow- 
erless to  secure  sound  results  in  large,  difficult,  or  complicated  cases. 
The  introduction  of  this  invention  has  made  it  possible  to  execute 
with  gold,  operations  which  previously  were  impossible  ;  not  the  least 
advantage  resulting  from  its  use  is  that  the  operator  has  free  use  of  the 
left  hand  to  assist  the  right. 

Quality  of  the  Rubber. — The  quality  of  the  rubber  greatly  modi- 
fies the  facility  of  its  application.  It  should  be  of  medium  thickness 
and  of  light  color,  as  it  then  absorbs  less  light.  It  should  be  freely 
extensible  and  so  elastic  that  when  the  thumb  is  forcibly  pressed  into  it 
it  returns  to  its  normal  form  on  the  removal  of  the  force.  If  it  re- 
sponds to  this   test  it  will  not  tear  if  fairly  applied. 

The  size  and  form  of  the  piece  should  be  such  as  to  avoid  encum- 
bering the  face  of  the  patient  and  to  permit  the  lateral  extension  to  be 
folded  out  of  the  way  in  such  manner  as  to  prevent  obstruction  of  the 
view.  The  form  generally  best  suited  is  a  triaufjle,  which  form  also 
permits  of  its  most  economical  use. 

For  the  front  teeth  the  piece  should  be  moderately  small  ;  for  the 
bicuspids  and  molars  the  size  should  be  ample  and  is  best  adapted  when 
cut  from  strips  about  seven  and  a  half  inches  in  width. 

The  selected  piece  should  have  holes  cut  in  it  of  such  size  as  to 
correspond  with  the  dimensions  of  the  teeth  over  which  it  is  to  pass. 
When  more  than  one  hole  is  required  the  holes  should  be  at  such  dis- 
tances apart  as  will  present  a  sufficient  amount  of  material  to  allow  for 
the  take-up  in  the  application,  so  that  the  strait  which  passes  between 
the  teeth  shall  be  sufficient  to  allow  the  edge  to  be  carried  upward  to 
form  a  valve  at  the  cervices  of  both  teeth  and  not  be  under  such  strain 
as  to  interfere  with  the  valvular  action  of  the  edges  of  the  rubber.  At 
the  same  time  there  should  be  no  excess  to  hamper  the  view  or  inter- 
fere with  the  placement  of  the  filling  material. 

Attention  to  the  valvular  arrangement  of  the  dam  at  the  cervix  wall 
avoid  subsequent  difficulty  and  will  prevent  in  many  instances  the 
infliction  of  pain  in  using  ligatures  except  upon  the  tooth  under  treat- 
ment and  the  adjacent  one.     The  appearance  of  this  valve  is  shown  in 


USE   OF  RUBBER  DAM.  241 

Fio.  207.  Fig.  209. 


perspective  by  Fig.  208,  a,  h,  c, 
(L    The  holes  in  the  rubber  may 

Fig.  208. 


"1  -  'r  r--"  1 

a  bed 

Diagrammatic  drawing  :  form  of  valve. 


be  formed  with  a  punch  of  suit- 
able size,  which  should  be  forced 
upon  the  end  of  a  close-grained 
piece  of  hard  wood.  They  may 
be  made  with  a  little  practice 
by  drawing  the  rubber  over  a 
round-ended  instrument  w'ith 
some  force  and  pricking  the 
rubber  at  a  suitable  point  with 
a  sharp  knife,  when  a  round 
section  escapes.  The  difference 
in  size  of  the  holes  is  deter- 
mined by  the  distance  from  the 
end  of  the  instrument  at  which 
the  puncture  is  made.  The  deter- 
mination, however,  of  size  and 
distance  is  not  easily  made  in 

this  manner.  The  best  appliance  for  the  purpose  is  the  Ainsworth 
punch  (see  Fig.  209),  with  which  complete  control  of  size  and  distance 
may  be  easily  effected. 

16 


The  Ainsworth  punch. 


242 


EXCLUSION  OF  MOTSTURE. 


The  arrangement  of  the  holes  in  the  triangular  piocc  should  differ 
for  each  section  of  the  mouth. 

Fig.  210  shows  a  piece  for  the  central  incisors.  The  figures  repre- 
sent inches. 

Fig.  211  shows  the  arrangement  of  holes  for  the  uj^per  bicuspids 
(1 11(1  molars.  It  will  be  observed  the  line  of  holes  is  not  parallel  with 
llic  ujiper  edge. 

Fig.  210.  Fig.  211.  Fk;.  212. 

11"  .<^  ,fi 


For  central  incisors. 


For  upper  bicuspids  and 
molars. 


For  lower  bicuspids  and 
molars. 


Fig.  212  shows  the  arrangement  for  the  lotrer  bicuspids  and  molars. 
Here,  too,  the  line  of  holes  is  not  parallel  Avith  the  edge,  to  allow  for 
the  difference  in  distance  from  the  commissure  of  the  lips  to  the  ante- 
rior and  posterior  holes. 

Fig.  213  shows  the  arrangement  when  the  lower  i)icisors  and  canines 
are  included.     Here  the  line  of  the  apertures 
Fig.  213.  is  curved. 

By  conforming  to  these  arrangements  of 
the  openings  in  the  rubber,  and  by  extend- 
ing the  line  in  conformity  with  it,  as  well  as 
by  increasing  the  size  of  the  piece,  any  num- 
For  lower  front  teeth.  ^^cr  of  liolcs   may  be  made,  to  include  any 

])()rtion  or  all  of  the  teeth  of  one  quarter  of 
the  denture  when  that  may  be  required. 

The  number  of  apertures  in  the  rubber  should  be  such  as  to  give 
easy  access  to  the  operation  and  to  permit  the  free  entrance  of  light. 
For  the  anterior  teeth  five  to  six  holes  are  necessary,  and  for  the  pos- 
terior teeth  from  four  to  six  as  may  be  needed  to  secure  the  above-stated 
objects.  In  general,  at  least  two  teeth  anterior  to  the  one  operated 
upon,  and  when  admissible  the  one  posterior,  should  be  included. 

The  Placement  of  the  Dam. — When  the  teeth  are  not  in  firm  con- 
tact or  when  their  attachments  are  flexible  the  adjustment  of  the  dam 
is  simple.  But  when  the  teeth  are  rigid  certain  preliminary  conditions 
should  be  secured.  It  has  been  pointed  out  in  speaking  of  the  prepara- 
tion of  the  teeth  for  a  series  of  operations  that  they  should  be  well 
cleaned  of  any  deposits  Avhich  may  be  upon  them  and  be  })olished  on 
their  approximal  surfaces.  This  makes  easier  the  insertion  and  the 
application  of  the  rubber. 


USE  OF  RUBBER  DAM.  213 

Generally  where  the  case  under  treatment  is  an  approximal  surface 
the  necessary  preparatory  separation  makes  easy  the  immediate  open- 
ing of  any  interstices  near  the  operation.  In  cases  of  extreme  fixa- 
tion of  the  teeth  a  piece  of  rubber  dam  placed  for  a  day  or  so  in  a 
coujile  of  the  neighboring  spaces  makes  it  easy  to  enter  the  margin  of 
the  interstices.  The  passage  of  a  silver  tape  with  a  little  benne  oil  or 
cosmolin  on  it  often  answers  as  an  equivalent  means.  In  the  front 
teeth  a  thin  wedge  inserted  just  above  a  tight  point  permits  an  easy 
entrance. 

The  preliminary  silking  of  the  adjoining  spaces,  particularly  if  the 
silk  be  coated  with  cosmolin  or  its  equivalent,  also  facilitates  the 
passage  of  the  rubber,  and  for  this  purpose  soaping  the  under  surface 
of  the  rubber  adjacent  to  the  holes  is  recommended. 

At  tirst  the  novice  finds  difficulty  in  making  application  of  the  dam, 
but  practice  cultivates  facility.  In  general  it  is  better  to  commence 
with  the  anterior  hole  and  proceed  posteriorly  until  all  the  intended 
teeth  are  included.  Thus  fi)r  the  left  lower  teeth  the  rubber  is  taken 
with  the  index  fingers  applied  to  the  upper  surface,  the  other  fingers  to 
the  under  surface,  and  is  grasped  near  the  hole  for  the  front  bicuspid  ;  the 
hole  is  extended ;  the  edge  of  the  rubber  is  inserted  in  the  mesial  inter- 
stice and  is  carried  down  to  the  gum.  It  is  then  drawn  over  the  tooth 
and  passed  into  the  next  interstice  in  the  same  manner.  This  method 
is  pursued  with  each  tooth  until  all  are  included.  The  passage  of  the 
rubber  is  facilitated  by  helping  it  downward  l)v  the  insertion  of  floss 
silk,  Avhich  is  held  taut,  and  with  a  firm  and  gently  sliding  movement 
the  rubber  is  conveyed  toward  the  cervix. 

When  the  most  distant  tooth  is  the  lower  third  molar,  it  is  generally 
best  when  the  cavity  is  on  either  side  of  the  last  interstice  to  pass  the 
jaws  of  a  dam  clamp  through  the  posterior  hole  ;  the  clamp  is  then  made 
to  grasp  the  tooth,  the  dam  is  conveyed  to  the  gum  by  silking,  and  the 
adjustment  is  then  carried  forward  from  tooth  to  tooth.  The  same  pro- 
cedure is  sometimes  applicable  with  short  third  molars  in  the  upper 
denture,  or  in  case  any  of  the  posterior  teeth  are  so  shaped  as  not  to 
retain  the  rubber. 

When  the  rubber  is  adjusted  over  the  teeth  the  purpose  of  the  dam 
is  eifected  by  directing  the  edge  of  the  dam  under  the  free  margin  of 
the  gum.  This  is  done  by  passing  a  silk  thread  around  the  tooth,  and 
crossing  the  ends,  Avhen  by  a  drawing  movement  of  the  thread  it  travels 
down  the  inclined  surface  of  the  cervix,  carrying  the  dam  with  it,  thus 
making  a  more  secure  formation  of  the  valve. 

This  method  avoids  the  needless  paining  of  the  patient  caused  by 
pushing  the  threads  against  the  gum  with  instrimicnts.  Whenever 
necessary  for  securement  the  ligature  should  be  tied.     This  should  be 


244  EXCLUSION  OF  MOISTURE. 

done  to  the  teeth  on  both  sides  of  an  upproxinuil  cavity.  It  is  neces- 
sary here  to  place  the  cervical  margin  of  the  cavity  in  full  view  and  to 
make  certain  the  exclusion  of  moisture,  which  otherwise  might  pass  the 
valve  by  capillary  attraction. 

The  ligature  should  usually  be  passed  but  once  around  the  tooth  and 
then  be  tied  with  a  surgeon's  knot,  the  place  of  the  knot  being  on  the 
outside.  When  there  is  much  strain  the  thread  may  be  passed  twice 
around  the  tooth,  but  this  should  be  avoided  as  being  more  painful  and 
as  increasing  the  bulk  of  the  ligature. 

To  prevent  the  rubber  from  displacement  by  the  movement  of  the 
cheeks  on  the  posterior  teeth  when  they  are  long,  if  after  drying  the 
surface  a  little  sandarac  or  damar  varnish  is  applied  at  the  last  inter- 
stice, the  rubber  becomes  fixed. 

In  cavities  extending  above  the  cervix  where  a  ligature  cannot  be 
placed  above  the  cervical  border  of  the  cavity,  other  means  have  to  be 
adopted  to  obstruct  the  entrance  of  fluids.  Here  the  strait  of  rubber 
between  the  holes  should  be  much  wider  than  usual ;  the  abundant  fold 
may  then  be  forced  beyond  this  margin  with  a  matrix,  when,  by  drying 
the  parts  and  by  the  deft  introduction  of  alcohol  varnish  and  suitable 
wedges,  drvness  of  the  parts  is  attained.  In  the  most  extreme  cases  of 
this  nature  the  part  beneath  the  normal  gum  line  may  be  filled  w'ith 
a  permanent  plastic  substance,  as  described  in  the  section  on  Lining 
Cavities  (see  Chapter  X,,  p.   258). 

The  Securement  of  the  Dam  from  Displacement. — AVhen  the 
teeth  are  short  from  incomplete  development  or  when  their  form  is 
tapering  from  the  gum  toward  the  occlusal  aspect  there  is  always  ten- 
dency of  the  rubber  to  escape,  and  the  contraction  of  the  commissure 
of  the  lips  tends  to  the  displacement  of  the  dam  at  the  posterior  teeth, 
the  latter  movement  often  being  sufficient  to  overcome  the  friction  of 
the  ligatures.     When  these  difficulties  arise  a  clamp  is  required. 

The  Clamp. — This  is  an  instrument  of  much  value  not  only  as  a 
means  of  securement  of  the  rubber,  but  as  an  adjunct  to  prevent  the 

Fk;.  214.  Fig.  215. 


Dr.  Southwiek's  clamps.  Dr.  Huey's  clamps. 


rubber  from  obstructing  the  view.  Clamps  are  more  especially  needed 
to  detain  the  rubber  on  the  molars  and  are  rarely  required  for  the  bicus- 
pids or  the  anterior  teeth,  since,  if  the  foregoing  directions  are  followed,. 
the  necessity  for  their  use  will  but  seldom  be  presented. 


USE  OF  RUBBER  DAM. 


245 


Forms  of  Clamps. — For  the  molars  various  sizes  and  shapes  of  the 

"  Southwick  "  and  of  the  "  Huey  wisdom-tooth  clamp "  are  sufficient 

for  general  use.     In  addition  to  these  "  Palmer's  set  of  eight,"  after 

the  sharp  points  of  the  jaws  are  rounded,  will  furnish  the  requisite 

variety. 

Fig.  216. 


Dr.  Delos  Palmer's  set  of  eight  clamps. 

The  AppUcation  of  the  Clamp. — The  selected  clamp  is  extended 
by  the  clamp  forceps  to  enable  it  to  pass  over  the  molar.  It  is  con- 
veyed to  the  middle  portion  of  the  tooth,  when  the  inner  beak 
should  be  brought  against  the  tooth  at  the  gum  margin  ;  then  with 
this  point  as  a  fulcrum  the  outer  beak  is  carried  to  the  cervix  on  the 
buccal  surface.  Much  pain  may  be  avoided  in  the  employment  of 
this  appliance  by  deft  and  careful  placement.  Injury  of  the  gum  and 
needless  pain  has  frequently  been  inflicted  by  careless  use  of  force  in 
the  application  of  this  appliance.  JNIuch  of  this  may  be  avoided  by 
the  previous  ligation  of  the  tooth,  which  will  prevent  the  tendency  of 
the  clamp  to  descend  beneath  the  gum  when  the  necks  of  the  teeth 
are  much  inclined  inward. 

When  it  is  necessary  to  force  the  clamp  against  the  soft  tissues  the 
previous  application  of  a  solution  of  cocain  will  obtund  the  tissue  and 
render  the  application  tolerable. 

The  Arrangement  of  the  Dam  on  the  Face. — This  concerns  the 
convenience  of  the  operator  and  the  comfort  of  the  patient.  To  give 
easy  access  and  permit  the  entrance  of  light,  the  rubber  is  drawn  aside 
at  each  upper  corner  by  dam-holders.  The  simpler  forms  of  these  are 
sufficient  and  are  more  convenient  than  the  more  complicated  ones  when 
triangular  pieces  of  rubber  are  employed.  In  addition  a  supporter, 
shown  at  Fig.  218,  passes  over  the  head  and  engages  at  each  end  with 
the  holder.  The  comfort  of  the  patient  is  secured  by  including  a  nap- 
kin along  with  the  rubber  in  the  clasps  of  the  holder.  The  excess  of 
the  rubber  at  each  side  should  be  taken  up  in  a  fold  and  secured  to  the 


246 


EXCLUSION  OF  MOISTURE. 


napkin  by  dressing  pins.     Tlic  suspended   part  of  the  riil)ber  is  kept 
taut  by  ])endent  weights. 

The  ap])]icati()u  and  arrangement  of  the;  daiu  becomes         Fk;.  218. 
by  practice  a  very  simple  matter,  and  should  not  be  the 
occasion  of  discomfort  or  pain  to  the  patient.  f 

Fig.  217. 


D<.'sif,ni  of  Dr.  Cogswell. 

The  Use  of  Napkins. — There  are  many  instances  of  simple  cases  in 
accessible  positions  not  of  approximal  surfaces,  when  the  general  flow 
of  saliva  can  be  kept  under  control  by  the  saliva  ejector,  when  it  is  not 
necessary  to  use  a  rubber  dam.  Also  for  children,  when  the  teeth  are 
too  short  to  permit  the  correct  application  of  the  dam,  it  is  necessary  to 
find  other  means  to  control  the  moisture.  Here  the  reliance  is  upon 
napkins,  and  with  them  mneh  skill  may  be  displayed  by  deft  operators. 
For  this  purpose  the  napkin  should  not  be  over  eight  inches  square. 
The  manner  of  folding  is  to  carry  two  adjacent  edges  to  the  diagonal 
of  the  napkin,  and  then  fold  again  in  like  manner ;  by  this  plan  the 
folds  are  held  in  place. 

Strips  of  "  bird's-eye  "  linen  of  various  lengths  and  widths  are  also 
serviceable  for  simple  cases  and  for  children. 

To  apply  a  napkin  to  the  upper  right  side,  the  point  is  taken  between 
the  left  index-fiuger  and  the  thumb,  the  broad  end  being  held  at  the 
same  time  by  the  right  hand.  The  lip  near  the  right  commissure  is 
everted,  the  point  is  inserted  here,  and  by  the  taut  action  of  the  left 
hand  the  napkin  is  next  laid  between  the  gum  and  the  lip.  It  is  then 
carried  backward  until  it  reaches  the  duct  of  Steno,  when  the  left  index 
finger  is  applied  to  maintain  the  compression  at  this  latter  point.  The 
free  end  of  the  napkin  lies  upon  the  lower  lip.  For  the  left  side  the 
action  is  the  same  by  the  reversal  of  the  hands. 

For  the  lorver  teeth  the  application  differs  by  commencing  for  each 
side  at  the  upper  canine  of  that  side.  When  the  duct  of  Steno  is 
reached  a  fold  is  made  to  eifect  the  compression  of  the  orifice  of  the 
duct,  then  the  napkin  is  laid  between   the  cheek  and  the  lower  teeth 


USE  OF  RUBBER  DAM. 


247 


and   kept   in   position   by  the   left  index  finger,  a  mirror,  or  a   cheek- 
holder. 

An  important  preliminary  to  the  application  of  a  napkin  to  these 
positions  is  that  the  saliva  ejector  be  first  placed  in  action  and  that  the 
surfiices  of  the  gum  and  cheek  be  wiped  to  dryness,  to  cause  the  napkin 
to  cling  to  the  surface.  If  the  surfaces  are  covered  with  mucus  and 
at  the  same  time  are  Avetted  with  saliva,  the  napkin  easily  becomes 
displaced. 

For  the  inner  surface  of  the  lower  teeth  a  considerable  fold  of  cot- 
tonoid  or  similar  substance  laid  beneath  the  tongue  materially  prevents 
access  of  saliva  here,  and  also,  by  preventing  the  contact  of  the  tongue 
with  the  teeth,  lessens  the  opportunity  for  the  access  of  moisture  by 
capillary  attraction  betAveen  the  tongue  and  the  teeth  under  treatment. 
In  instances  where  the  form  of  the  parts  permits,  the  fold  of  cottonoid  or 
of  linen  may  be  retained  in  place  by  a  dam 
clamp  upon  any  adjacent  posterior  tooth. 

For  the  medication  of  cavities  where  it  is 
important  to  confine  the  remedy  to  the 
tooth  ;  in  short  operations,  such  as  temporary 
stoppings,  and   particularly  for  the  simpler 

Fk;.  '219. 


Fig.  220. 


The  Deiihaiii  shield. 


'shield  in  use 


cases  of  children,  the  Denham  coffer-dam  shields  shown  in  Figs.  219, 
220  are  of  much  advantage,  more  particularly  for  the  lower  teeth. 
AVith  the.se  the  ejector  forms  a   valuable  aid. 


NAUSEA. 

The  contact  of  rubber  dam  with  the  tongue  and  the  contiguous  parts, 
the  presence  of  napkins',  and  the  touch  of  the  fingers  to  the  oral  surfaces 
frequently  excites  nausea.  With  some  persons  this  kind  of  distress  is 
extreme  and  produces  simulation  of  faintness  and  nervousness.  This 
condition  may  generally  be  relieved  by  the  use  of  aqua  camphora,  a  few 
drachms  being  used  as  a  gargle  to  the  mouth  and  the  throat.  When 
indications  of  faintness  appear  a  drachm  may  be  swallowed  with  imme- 
diate benefit. 

In  case  excessive  nausea  is  occasioned  by  the  contact  of  the  appli- 


248  EXCLUSION  OF  MOISTURE. 

ances  with  the  tongue  or  pahite,  tliese  surfaces  may  be  painted  with 
tincture  of  camphor.  Spasmodic  coughing,  not  infrequent  with  nervous 
])ersons,  yields  to  tlie  same  treatment.  Camphor  appears  to  relieve  in 
these  instances  by  its  antispasmodic  power,  and  it  is  stated  to  have  also 
a  specific  action  u])on  the  eighth  pair  of  nerves. 

Nervousness  coming  on  during  any  of  the  operations  upon  the  teeth 
mav  as  easilv  and  in  the  same  manner  be  avoided.  It  will  be  observed 
that  in  neither  of  these  conditions  are  the  first  signs  of  ajjprDaching 
synco})e  a[)parent,  viz.  sighing  respiration,  pallor,  and  clammy  perspi- 
ration of  the  face. 

A  condition  somewhat  simulating  approaching  syncope  sometimes 
appears  in  connection  with  the  use  of  the  rubber  dam,  due  to  partially 
suspended  respiration,  which  is  caused  not  so  much  by  the  obstruction 
of  the  mouth  as  by  the  unpleasant  sensations  occasioned  by  the  appli- 
cation and  ])resence  of  the  dam.  This  may  at  once  be  overcome  by 
requesting  the  patient  to  breathe  deeply  through  the  nose. 


CHAPTER   X. 

THE  SELECTION  OF  FILLING  MATERIALS  WITH  REFER- 
ENCE TO  CHARACTER  OF  TOOTH  STRUCTURE,  VARIOUS 
ORAL  CONDITIONS  AND  LOCATION,  DEPTH  OF  CAVITY 
AND  PROXIMITY  OF  THE  PULP— CAVITY  LINING,  WITH 
ITS  PURPOSES. 

By  Louis  Jack,  D.D.S. 


The  general  object  in  view  in  the  filling  of  a  prepared  cavity  is  to 
secure  the  future  preservation  of  the  tooth  at  that  part  from  the  recur- 
rence of  caries.  This  involves  a  consideration  of  the  character  of  the 
material  to  be  used,  in  relation  to  its  adaptability  to  the  conditions  of 
age,  the  quality  of  the  teeth,  and  the  oral  conditions  which  for  the  time 
are  an  expression  of  the  general  state  of  the  organism.  The  habits  of 
the  patient  as  to  general  care  of  the  teeth  also  have  some  bearing  upon 
the  proliability  of  permanence  of  the  reparative  operation,  A  material 
adapted  to  preserve  the  teeth  when  they  are  of  resistant  quality  and 
when  the  general  health  is  sound  and  the  care  good,  may  be  out  of 
place  when  the  opposite  conditions  exist.  Methods  of  procedure  have 
some  bearing  upon  the  result,  and  the  influence  of  these  has  also  to  be 
kept  in  view. 

The  general  characteristics  of  the  material  to  be  used  as  a  pre- 
servative of  tooth  structure  are  of  importance  in  the  following  order  : 

Resistance  to  chemical  action  ; 

Capability  of  adaptation  to  the  surface  of  the  cavity  ; 

Sufficient  hardness  to  withstand  the  force  of  mastication  and  i\\Q  con- 
sequent attrition. 

Capability  of  form  and  smoothness  are  also  important  in  relation  to 
cleanliness,  which  more  than  any  other  indirect  influence  has  the  greatest 
bearing  upon  the  preservation  of  the  margins  from  subsequent  softening, 
as  will  further  appear. 

The  Materials. 

The  various  accepted  materials  in  use  are  :  gold,  tin,  amalgams,  the 
basic  oxid  cements,  gutta-percha. 

Tlie  first  three  named  may  be  designated  as  permanent  in  their  cha- 

249 


250  FTLLTXa   MATERIALS. 

racter,  and  the  others  as  of"  a  teni])orarv  nature,  whieli,  after  fulfilling 
important  uses  in  this  way,  are  often  preparatory  to  later  and  permanent 
treatment. 

Gold. — The  properties  of  u'old  whieh  adapt  it  for  the  restoration  of 
carious  teeth  are  its  pliability  and  softness,  which  permit  its  adaj)tati()n 
to  the  form  of  the  cavity  ;  its  tenacity,  which  gives  facility  of  introtluc- 
tion  and  consolidation  ;  and  its  agreeableness  of  color,  which,  when  the 
surface  is  solid,  smooth,  and  nnbnrnishcd,  a})proaches  more  nearly  the 
shade  of  the  teeth  than  any  other  metal. 

Notwithstanding  these  ap})ropriate  qualities  the  packing  of  gold 
re(]uires  the  employment  of  considerable  force  to  overcome  various 
resistances  to  its  adaptation  and  solid  condensation.  To  effect  the 
requisite  degree  of  density  percussive  force  frequently  becomes  necessary. 
The  effect  of  percussive  force,  if  employed  throughout,  is  liable  to  be 
expended  on  the  margin  toward  which  it  is  directed,  and  while  this  may 
not  inflict  any  injury  upon  the  borders  of  cavities  when  the  dentin  and 
enamel  are  dense,  it  often  proves  injurious  to  teeth  when  the  anatomical 
elements  of  the  structure  are  not  homogeneous  and  resistant. 

While  it  may  be  stated  with  the  strongest  assurance  that  gold  pos- 
sesses the  highest  preservative  qualities  and  promises  greater  durabil- 
ity and  more  satisfactory  results  than  any  other  material,  conditions 
are  often  presented  when  to  persist  in  its  use  would  lead  to  unsatis- 
factory results;  thus,  in  the  approximal  cavities  of  the  teeth  of  children, 
when  the  calcifying  process  has  not  become  complete  and  when  by  the 
use  of  the  required  force  some  impairment  of  the  incomplete  tissues  is 
almost  certain  to  ensue.  The  same  maladaptability  occurs  later  in  life 
when  senile  conditions  have  set  in,  when  the  teeth  not  only  have  lost 
their  density  from  the  peculiar  molecular  changes  which  take  place 
in  the  dentin  and  enamel,  but  when  usually  also  their  resistance  to 
chemical  influences  is  greatly  impaired.  These  conditions,  coupled  with 
the  usual  inability  to  properly  care  for  the  teeth,  render  the  use  of  gold 
very  questionable. 

Similar  states  of  the  dental  tissues  take  place  in  middle  life  in  both 
sexes,  but  more  particularly  in  women  during  the  pregnant  state, 
when  the  teeth  lose  their  resistant  power,  which  may  later  be  restored. 
AVhile  this  condition  lasts,  materials  requiring  less  force  should  be 
selected  until  restoration  of  resistance  has  occurred. 

The  mode  of  effecting  percussion  should  be  taken  into  account  in 
estimating  the  influences  which  bear  against  the  use  of  gold.  When 
percussion  is  effected  by  the  electro-magnetic  instruments  with  proper 
precautions  with  respect  to  the  placement  of  the  first  portions  of  gold, 
there  is  less  danger  of  marginal  injury  than  when  percussion  is  made 
with  the  hand  or  the  automatic  mallet. 


GOLD— TIN.  251 

Finally,  the  fact  must  also  be  recognized  that  in  cases  in  which  the 
character  of  the  structure  of  the  teeth  raises  a  question  as  to  the  adapt- 
ability of  gold,  the  physical  and  nervous  resistance  of  the  patient  is 
generally  below  that  which  would  enable  him  to  endure  the  ordeal 
connected  with  the  thorougli  completion  of  the  work  in  harmony  with 
the  high  standard  impressed  by  the  continued  advancement  which  has 
taken  place  in  dentistry. 

The  tendency  to  carles  of  the  teeth  is  a  general  consideration  to 
be  held  in  view  in  determining  the  propriety  of  employing  gold. 
When  the  enamel  is  hard,  the  dentin  solid,  and  the  general  tone  of 
the  health  excellent,  there  can  be  no  doubt  that  the  inherent  qualities 
of  gold  constitute  it  the  most  nearly  permanent  material.  When,  on 
the  contrary,  the  opposite  conditions  exist,  gold  becomes,  in  propor- 
tion to  the  prominence  of  the  unfavorable  states  present,  the  most 
questionable  material. 

No  correct  conclusion,  however,  can  be  reached  without  consideration 
of  the  state  of  the  oral  secretions  and  of  the  habits  of  the  patient  as 
to  the  care  taken  of  the  mouth.  The  first  stage  of  decay  of  the  teeth 
is  the  softening  of  the  enamel,  which  is  brought  about  as  the  conse- 
quence of  the  presence  of  carbohydrates  undergoing  fermentation  in 
secluded  positions,  which  effects  the  solution  of  the  enamel  at  these 
places  and  prepares  the  way  for  the  occurrence  of  caries  of  the  dentin. 
Hence  a  correct  hygienic  condition  of  the  mouth  is  the  most  important 
requirement  for  the  protection  of  the  margins  of  the  tooth  adjacent  to 
fillino^s  intended  to  restore  them. 

The  reaction  of  the  oral  secretions  in  their  bearing  upon  the  permanence 
of  dental  operations  has  also  much  weight,  since,  when  these  secretions 
have  an  acid  reaction,  as  the  consequence  of  the  presence  of  fei'menting 
material,  this  condition  favors  the  continuance  of  the  process.  A  con- 
tinual acid  state  of  the  oral  fluids,  as  a  consequence  of  derangements  of 
health  such  as  occur  in  impaired  digestion  or  attend  the  rheumatic 
diathesis,  should  be  taken  into  account.  Only  an  appreciable  degree 
of  alkalinitij  can  inhibit  enamel  solution  unless  the  general  and  local 
hv^ienic  conditions  are  favorable. 

Tin. — This  metal,  in  the  form  of  foil,  shavings,  and  rolled  into 
thin  strips,  while  not  in  much  use,  should  have  a  wider  field  than  is 
accorded  it.  It  possesses  great  softness,  when  chemically  pure,  and 
is  readily  adapted  to  the  walls  of  cavities  for  the  reason  that  it  pre- 
sents less  resistance  since  it  does  not  harden  under  the  mechanical  force 
employed.  For  the  same  reason,  when  the  cavity  is  overfilled,  the  con- 
densing appliances  effect  by  the  lateral  movement  of  the  mass  a  better 
and  more  easily  procured  adaptation  with  the  cavity  walls.  For  these 
reasons  it  possesses  excellent  preservative  qualities. 


252  FILLING  MATERIALS. 

Till  is  also  a  poorer  thermal  conductor  than  gold,  and  this  is  an 
important  consideration  wlicn  thermal  irritation  is  to  be  avoided,  and  is 
of  great  value  in  deep  cavities  approachino;  dani^crously  near  to  tiie  pul}). 

The  objections  to  this  metal  are  its  color  when  exposed  to  view  and 
its  softness,  which  greatly  lessens  its  value  in  positions  where  it  may  be 
subject  to  severe  attrition. 

Its  most  important  use  is  for  the  temporary  teeth  of  children,  Avhere 
it  may  be  easily  inserted  and  readily  condensed,  and  rapid  progress  in 
its  introduction  may  be  made,  producing  good  results. 

Except  when  freshly  prepared,  tin  is  not  cohesive,  a  quality  which 
cannot  be  restored  by  heat,  as  may  be  done  with  gold. 

AMALGAMS. 

Tlieir  Composition. — The  essential  metals  which  enter  into  the  com- 
position of  the  dental  amalgams  are  silver,  tin,  and  mercury.  To 
these  are  added  various  metals  in  varying  proportions  to  modify  the 
"  setting,"  the  color,  and  the  affinity  for  sulfur  compounds.  For  these 
purposes  gold  is  used  to  influence  the  rate  of  chemical  combination,  and 
it  also  affects  the  color.  Zinc  and  copper  are  added  in  order  to  modify 
the  shade  and  also  to  lessen  the  affinity  for  sulfur. 

The  effect  of  various  proportions  of  the  metals  entering  into  the 
formulas  upon  the  working  qualities  of  an  amalgam  is  extremely  puz- 
zling ;  slight  differences  in  proportions  causing  widely  varying  results. 

The  order  in  which  the  metals  are  introduced  into  the  crucible  and 
the  degree  of  heat  to  which  the  mass  is  subjected  in  the  fusing  process 
also  affect  the  working  qualities. 

The  Proportion  of  the  Ingredients. — Valuable  tables  have  been  given 
by  Dr.  Black  which  indicate  that  a  nearly  definite  ratio  betw^een  the 
silver  and  tin  should  be  maintained.  This  ratio  is  found  to  be  approxi- 
mately as  follows — Silver  65,  Tin  35 — when  only  these  two  metals  are 
used  to  make  the  alloy.  Whatever  addition  of  a  modifying  metal  is 
introduced  should  be  of  small  quantity  and  at  an  equivalent  reduction 
of  the  percentage  of  the  tin. 

The  ingot  of  the  alloy  should  be  finely  divided  either  by  filing  or  by 
thin  shavings  made  by  turning  them  off  in  a  lathe.  When  the  commi- 
nution of  the  alloy  is  made  immediately  before  using,  amalgamation  is 
more  easily  effected  than  when  the  filings  are  kept  for  any  considerable 
time,  unless  in  the  latter  case  there  is  a  disproportion  of  tin  or  gold. 
This  has  been  attributed  to  oxidation  of  the  particles  taking  place,  which 
would  retard  the  amalgamation.  Silver  not  being  an  oxidizable  metal 
under  ordinary  conditions,  the  cause  of  the  tardy  combination  with 
mercury  is  to  be  found  in  the  attachment  of  sulfids  to  the  surface,  and 
also    to    the   influences  of  occluded   gases,  which  also  tend  to  retard 


AMALGAMS.  253 

amalgamation.  It  is  a  notable  fact  that  while  freshly  comminuted  alloy 
will  more  readily  amalgamate,  it  requires  more  mercury  than  aged 
alloy. 

More  recent  investigations  by  Dr.  Black  tend  to  the  conclusion  that 
the  difference  in  capacity  for  mercury  observed  in  freshly  cut  alloy  and 
that  which  has  been  cut  for  some  time  is  due  to  the  difference  in  molec- 
ular arrangement  of  the  alloy,  brought  about  by  the  comminuting  pro- 
cess, which  has  the  effect  of  hardening  the  grains  and  condensing  their 
texture  in  the  same  manner  that  hammering  the  ingot  would  harden  the 
entire  mass.  By  the  application  of  sufficient  heat  the  particles  of  alloy 
mav  be  "  aged  "  artificially,  and  this  aging  is  presumed  to  be  simply  an 
annealing  process.  The  capacity  of  the  aged  alloy  for  mercury  is 
markedly  different  from  that  of  the  freshly  cut  alloy,  as  are  also  the 
Avorking  qualities  of  the  resulting  amalgam  mass,  the  aged  alloy  form- 
ing a  slower  setting  and  much  smoother  working  amalgam  than  that 
made  from  freshly  cut  alloy.  For  the  further  details  of  this  subject 
see  Chapter  XIII.,  on  Plastic  Fillings. 

It  is  held  by  many  that  the  proportion  of  mercury  should  be  in  some 
excess,  to  give  decided  plasticity  to  the  mass  for  the  purpose  of  securing 
complete  amalgamation  of  the  particles  of  the  alloy.  When  the  amal- 
gamation is  complete  the  redimdance  is  forced  out  through  chamois 
skin,  or  the  mass  is  kneaded  in  a  napkin  or  piece  of  China  silk,  which 
forces  through  the  meshes  most  of  the  excess.  It  is  claimed  that  this 
method  of  conducting  the  amalgamation  effects  an  approximately  cor- 
rect atomic  relation  of  the  metals  with  each  other;  it  being  held  that 
the  freer  proportion  of  mercury  during  the  mixing  process  tends  to  this 
result,  as  the  redundant  metal  is  carried  out  with  the  excess  of  mercury 
as  it  is  expressed.  On  the  other  hand,  it  is  maintained  that  the  propor- 
tions of  any  given  alloy  and  mercury  which  will  produce  an  amalgam 
fulfilling  every  requirement  should  be  established  by  experimentation, 
and  thereafter  be  weighed  out  in  those  proportions. 

The  Distinguishing  Features  of  a  Good  Ama/gam. — An  amalgam  (1) 
Should  be  non-shrinking ;  (2)  Should  have  edge  strength ;  (3)  Should 
maintain  lightness  of  color  under  the  varying  oral  conditions ;  (4)  Should 
tend  to  assume  a  spheroidal  surface.  A  further  qualification  is  that  the 
surfiices  of  the  material  may  not  undergo  electrolysis. 

Indisposition  to  shrinkage  is  secured  by  a  close  conformity  of  the 
alloy  with  the  proportions  above  given. 

Edge  strength  is  a  term  which  has  not  as  yet  had  a  clear  defini- 
tion in  respect  to  the  causes  which  determine  the  deficiency  of  this 
quality.  The  maintenance  of  unchangeability  of  the  surface  is  directly 
related  to  this  important  desideratum,  as  roughening  and  erosion  of  the 
margins  is  the  result  of  molecular  w^aste,  which  causes  a  ragged  and 


254  FILLING   MATERIALS. 

unclean  appearance  of  the  edges  and  an  apparent  sejiaration  of  tlic  fill- 
ing from  the  borders  of  the  cavity.  The  causes  Avliich  produce  this 
condition  are  slowly  progressive  and  are  continuous. 

This  kind  of  erosion  is  most  marked  when  contraction  takes  place, 
from  incorrect  preparation  or  improper  ratio  of  the  metals  entering 
into  the  formula,  or  careless  manipulation,  when  cai)illary  defects  are 
liable  to  occur  at  the  margins. 

The  most  probable  hypothesis  to  account  for  these  observed 
changes  is  that  the  presence  of  moisture  having  acid  reaction,  by 
inducing  electrolytic  action  between  the  metals,  brings  about  the  erosion 
of  the  material  immediately  within  the  margins.  In  these  cases  tlie 
exposed  surfaces  generally  suffer  little  waste,  for  the  reason  that  they 
are  subject  to  the  continued  movement  of  the  oral  fluids,  but  it  is  often 
observed  that  entire  fillings  undergo  a  similar  gradual  loss  and  disappear. 
This  result  is  common  where  there  is  an  excess  of  gold  or  mercury.  In 
some  instances  the  above  described  action  takes  place  to  a  limited  degree 
upon  the  whole  surface  in  proximity  with  the  dentin,  when  a  residue 
is  found  upon  the  filling  as  well  as  on  the  surface  of  the  dentin. 

The  conclusion  from  these  observed  fiicts  is  that  the  securement  of 
edge  strength  depends  upon  an  approximation  to  the  chemical  ratio  of  the 
elements  of  the  alloy.  This  would  appear  to  be  most  nearly  secured 
when  the  material  is  subject  neither  to  shrinkage  nor  expansion.  Expan- 
sion under  some  circumstances  might  produce  marginal  space  and  there- 
fore lead  to  the  same  result ;  for  instance,  if  in  apjiroximal  or  buccal 
cavities  the  depth  were  greater  at  one  division  than  another  the  expan- 
sion of  the  thicker  part  of  the  filling  would  tend  to  raise  the  edge  sur- 
rounding the  shallow  part  of  the  cavity,  and  would  then  subject  the 
edge  of  the  filling  to  electrolytic  changes. 

A  related  condition  sometimes  appears  when  an  amalgam  filling, 
quite  hard  at  completion,  after  some  years  becomes  comparatively  soft, 
which  apparently  is  due  to  molecular  changes. 

The  close  conformity  of  the  alloy  to  the  proportions  recently  estab- 
lished by  Black,  and  foreshadowed  by  the  much  earlier  experimentation 
of  Flagg,  furnishes  a  result  that  is  directly  conducive  to  fixity  of  form 
and  edge  strength  when  the  margins  of  the  cavity  are  overlapped. 

This  formula  is  approximately — silver,  68  ;  tin,  26  ;  copper,  5  ; 
zinc,  1. 

The  maintenance  of  size,  form,  and  strength  dei3ends  largely,  if 
not  entirely,  upon  the  influence  of  silver.  When  the  proportion  of 
this  element  becomes  less  than  60  per  cent,  of  the  formula,  the  tendency 
to  shrinkage  appears  and  holds  a  nearly  direct  relation  with  the  diminu- 
tion. When  the  ratio  of  silver  advances  above  70  per  cent,  the  expan- 
sion becomes  marked,  and  at  80  per  cent,  is  excessive. 


THE  MINERAL   CEMENTS.  255 

Lightness  of  Color. — The  means  by  which  this  property  may  be 
secured  have  not  as  yet  been  well  determined  and  should  be  the  sub- 
ject of  extended  experimentation.  Some  of  the  so-called  white  alloys 
approximate  stability  in  this  respect,  but  the  ratios  of  the  modifying 
metal  have  not  been  accurately  determined. 

Amalgam  as  a  filling  material  is  adapted  to  large  cavities  in  the  jjos- 
terior  teeth  when  the  margins  are  too  frail  to  permit  gold  to  be  con- 
densed ;  for  positions  where  mechanical  force  cannot  be  exerted  with 
efficiency,  notably  the  cavities  of  the  third  molar ;  distal  cavities  of  the 
second  molar  when  of  large  size  ;  and  the  lingual  cavities  of  the  lower 
molars.  When  the  teeth  are  of  deficient  resistance  and  when  the  con- 
dition of  the  oral  secretions  favors  the  rapid  progress  of  caries  these 
limitations  may  be  extended  to  cavities  where  otherwise  gold  would 
appear  to  be  a  more  suitable  material. 

As  a  material  for  the  filling  of  the  deciduous  teeth  amalgam  possesses 
superiority  over  any  other  substance,  for  the  reasons  that  it  can  be  intro- 
duced with  less  effort  than  tin  and  has  greater  durability  than  either 
the  mineral  cements  or  gutta-percha  preparations  ;  the  exception  to  its 
use  here  being  when  the  conditions  prevent  retentive  formation  of  the 
cavity. 

Concerning  the /o/'?«  of  the  cuvitij  adapted  to  amalgam,  it  is  necessary 
that  the  retentive  formation  be  equally  exact  as  for  gold,  since  many 
of  the  formulas  in  use  undergo  slight  movement  for  some  time  after 
their  introduction,  during  which  there  is  liability  of  marginal  displace- 
ment which  may  lead  to  the  defects  treated  of  under  the  section  con- 
cerning "  edge  strength."  Amalgam,  while  presenting  in  its  appear- 
ance an  unfavorable  comparison  with  gold,  is  capable  of  rendering 
important  service  Avhen  every  consideration  is  given  to  the  require- 
ments governing  its  successful  employment. 

To  attain  the  best  results  in  the  use  of  the  amalgams  requires 
extreme  exactness  as  to  the  ratios  of  the  ingredients  and  great  care  in 
all  the  procedures  connected  with  the  formation  of  the  cavity,  the  form 
of  the  filling,  and  the  subsequent  finishing  process. 

The  disqualifications  of  amalgam  are  its  unsatisfactory  color  and  the 
unknown  character  of  the  composition  of  the  formulas  as  furnished  by 
the  depots  of  supply. 

THE   MINERAL   CEilENTS. 

Oxychlorid  of  Zinc. — This  material,  because  of  its  lacking  the 
quality  of  indestructibility,  is  contraindicated  in  all  exposed  situa- 
tions. It  possesses,  however,  a  considerable  degree  of  antiseptic  power, 
and  for  this  reason  renders  valuable  service  in  deep  cavities  not  nearly 
approaching  the  ]iulp,  or  even  here  \vhen  the  pul])  Avail  of  the  cavity 


256  FILLING   MATERIALS. 

has  been  previously  protected  by  a  layer  of  frutta-percha  or  a  disk  of 
asbestos  paper.  In  such  cases,  particularly  on  occlusal  aspects,  the 
cavity  may  bo  nearly  filled,  leaving  a  remainder  the  thickness  of  enamel 
to  be  completed  Avith  gold. 

For  the  filling  of  root  canals  and  pulj)  chambers  it  otFers  the  best 
solution  of  the  problem  of  preventing  septic  changes  in  the  devitalized 
dentin.  After  many  years,  fillings  of  root  canals  and  pulp  chambers 
of  this  material  remain  unchanged  and  are  found  clean  and  without 
odor  on  removal — a  result  that  is  not  presented  by  any  other  filling 
material  which  may  be  introduced  in  these  situations.  Here  it  is  im- 
]>ortant  that  the  material  be  not  mixed  very  thin,  especially  on  account 
of  the  danger  of  forcing  it  through  the  apical  foramen. 

A  further  use  of  this  substance  is  to  infiueuce  the  shade  of  devital- 
ized teeth  by  the  color  tone  it  imparts  to  the  crown  of  the  tooth  on 
account  of  its  whiteness.  This  is  enhanced  by  the  fact  that  it  comes 
into  exact  contact  and  remains  without  change,  a  quality  which  cannot 
be  given  to  gutta-percha  or  other  cements. 

As  a  temporary  filling  to  correct  extreme  sensitivity  of  dentin  in 
situations  or  under  conditions  which  forbid  ordinary  therapeutic  treat- 
ment, oxychlorid  of  zinc  lias  considerable  value.  Here  when  the  pulp 
is  not  closely  approached  it  may  be  retained  for  several  months  with 
considerable  advantage.  To  secure  the  best  results  the  proportion  of 
zinc  chlorid  should  be  slightly  greater  than  in  the  formulas  used  for 
ordinary  fillings. 

Zinc  Phosphate. — This  material,  because  of  its  greater  power  to 
withstand  the  influence  of  the  oral  secretions,  has  a  wider  use  than  the 
previously  described  cement.  It  cannot,  however,  be  depended  upon 
far  permanent  uses.  While  in  some  instances  it  may  remain  for  several 
years  when  the  oral  fluids  are  neutral  and  when  every  attention  is  given 
toward  the  attainment  of  cleanliness,  it  is  nevertheless  a  deceptive  sub- 
stance, since  it  is  liable  under  temporary  changes  of  the  secretions  to 
undergo  solution,  more  particularly  in  situations  near  the  gum.  When 
placed  in  approximal  cavities  it  is  extremely  liable  to  become  fissured 
at  the  cervical  margin  and  then  permit  carious  action  insidiously  to 
take  place. 

Unlike  oxychlorid  of  zinc,  the  phosphate  has  no  antiseptic  influence, 
hence  it  does  not  inhibit  decay  of  the  dentin  in  its  proximity.  Its  chief 
use  is  as  a  temporary  expedient  for  filling  cavities  on  labial  and  buccal 
surfaces,  where,  being  under  easy  observation,  it  may  be  used  with 
benefit.  On  account  of  its  chemical  solution  by  the  oral  secretions, 
however  slow  this  may  be,  it  requires  frequent  renewal. 

Zinc  phosphate  is  also  of  value  for  filling  the  principal  portion  of 
large  compound  cavities  where  the  teeth  would  be  injured  by  the  force 


CAVITY  LINING  IN  RESPECT  TO  PROXIMITY  OF  THE  PULP.   257 

employed  in  the  condensation  of  gold,  and  as  a  desideratum  to  avoid 
the  great  amount  of  time  required  to  fill  large  cavities  with  this  metal. 
It  also  here  imparts  in  some  instances  much  strength  to  frail  margins. 

In  the  cavities  which  early  form  upon  the  occlusal  surfaces  of  the 
permanent  molar  teeth  of  children  it  is  of  great  value,  as  here  it  is  kept 
clean  by  the  friction  of  mastication,  and  being  under  easy  observation 
can  be  renewed  when  this  is  required.  When  the  child  reaches  the  age 
to  have  permanent  operations  the  margins  may  be  shaped  for  the  reten- 
tion of  gold,  and  in  this  case  the  principal  part  of  the  cement  should 
be  allowed  to  remain. 

Zinc  phosphate  is  of  questionable  use  in  pulp  chambers  as  not  hav- 
ing antiseptic  properties,  and  being  porous  it  becomes  after  several 
years  quite  offensive.  For  the  same  reason  it  is  inadmissible  for  canal 
fillings.  Furthermore,  for  this  jiurpose  it  is  questionable,  on  account 
of  its  adhesiveness,  whether  it  is  capable  of  being  thoroughly  introduced 
into  root  canals.  All  things  considered,  it  is  for  these  purposes  greatly 
inferior  to  oxychlorid  of  zinc. 

Gutta-percha. — Compounds  of  gutta-percha  with  oxid  of  zinc  form 
a  useful  substance  for  temporary  fillings,  acceptable  for  teeth  of  low 
grade  at  points  not  subject  to  attrition.  Its  preservative  properties  are 
very  considerable,  and  were  it  not  subject  to  surface  degeneration  would 
in  the  situations  noted  be  a  nearly  permanent  material. 

The  requirements  for  its  successful  use  are  that  it  be  not  heated 
liigher  than  212°  F.,  that  the  cavity  be  quite  dry,  that  it  be  intro- 
duced in  small  pieces,  and  be  kept  under  continual  condensation  until 
cooled  to  prevent  shrinkage.     (See  Chapter  XIII.) 

Cavity  Lining  in  Respect  to  Proximity  of  the  Pulp. 

As  caries  approaches  the  pulp  it  reaches  a  period  when  the  proximity^ 
of  this  organ  is  so  close  as  to  require  much  care  to  avoid  irritation  and 
probable  congestion.  Under  these  circumstances  it  is  necessary  to 
avoid  thermal  conduction  and  to  exclude  chemical  influences.  After 
disinfection  of  the  dentin  some  substance  the  ingrediency  of  which 
is  non-irritating  and  non-conduetinir  should  be  selected  to  overlay  the 
pulp  wall  of  the  cavity.  Here  choice  must  be  made  between  gutta- 
percha and  either  of  the  classes  of  mineral  cements. 

When  the  use  of  gold  is  preferable  for  the  external  portion  of  the 
filling,  it  is  required  that  the  foundation  be  sufficiently  solid  to  with- 
stand the  force  to  be  applied  to  the  gold.  Hence  one  of  the  cements  is 
here  necessary.  Previous  to  the  placement  of  the  cement,  should  the 
pulp  be  near,  the  surface  should  be  covered  with  a  thin  solution  of  one 
of  the  resins  to  prevent  the  influence  of  the  fluid  element  of  the  cement 
from  producing  irritation.  Copal  ether  varnish,  a  solution  of  hard 
17 


258  FILLING  MATERIALS. 

Canada  balsam  in  chloroform,  or  the  solution  of  nitro-cellulose  in 
amyl  acetate  sold  as  ''  kristaline "  or  "  cavitine "  are  eifective 
materials  for  this  purpose.  When  the  cavity  is  deep  the  layer  of 
cement  should  be  brought  to  the  inner  line  of  the  retentive  grooves. 
As  soon  as  hardening  takes  place  the  metallic  covering  may  bo  given. 

When  the  shallowness  of  the  cavity  will  not  permit  a  considerable 
layer  of  the  cement,  a  metal  cap  covering  the  pulp  wall  of  the  cavity 
filled  with  the  cement  may  be  laid  in  ]>lace,  the  metal  of  the  cap  thus 
sustaining  the  force. 

These  forms  of  cavity  lining  are  of  great  utility,  and  should  be 
regarded  as  of  importance. 

Marginal  Cavity  Lining. — When  cavities  are  situated  on  approxi- 
mal  surfaces  of  the  teeth  and  extend  high  up  on  the  cervical  aspect  so 
as  to  place  them  beyond  the  probability  of  efficient  service  with  metal 
foils,  and  when  the  lateral  walls  of  cavities  are  weak  either  by  their 
thinness  or  by  instability  from  defects  of  structure,  some  form  of 
"  lining "  is  necessary.  In  the  one  case,  to  ensure  certainty  of  per- 
formance at  the  cervix  ;  in  the  other,  to  prevent  injury. 

For  the  cervical  part  the  choice  is  between  (1)  tin,  (2)  a  combination 
of  tin  and  gold,  and  (3)  amalgam. 

Tin  has  the  objection  when  superimposed  above  gold  that  it  suffers 
waste,  in  most  instances  by  electrolysis,  to  which  the  mixture  of  tin  and 
gold  is  not  liable.  This  latter  combination — made  by  folding  a  layer 
of  the  tin  within  the  gold  foil — appears  to  give  the  tin  protection.  This 
combination  is  more  plastic  and  more  yielding  than  gold  alone,  and 
permits  adaptation  and  consolidation  in  places  difficult  of  approach. 
When  used  in  connection  with  a  matrix  thorough  consolidation  may 
be  eifected  without  injury  to  the  cervical  margin  when  the  tissues  are 
not  dense. 

When  the  color  of  a  lining  at  the  cervix  will  not  be  objectionable, 
a  quick-setting  amalgam  answers  extremely  well,  and  may  at  the  same 
sitting  be  followed  by  the  completion  of  the  operation  with  gold.  In  this 
situation,  whatever  the  lining  material,  close  conformity  with  the  lines 
of  the  cervical  form  of  the  tooth  must  be  assured.  In  many  instances 
the  lining  and  the  completion  of  this  portion  of  the  filling  should  be 
effected  before  the  rubber  dam  is  placed,  when  the  lining  portion  is  for 
the  time  being  considered  in  its  relations  as  a  part  of  the  tooth. 

When  it  is  necessary  to  use  the  mineral  cements  on  approximal  sur- 
faces of  the  posterior  teeth  for  temporary  purposes,  the  cervical  border 
should  be  covered  with  a  line  of  gutta-percha  stopping,  to  protect  this 
vulnerable  part  of  such  fillings  from  the  exposure  of  this  border  by 
the  solution  to  which  they  are  there  liable. 

Lining  Lateral  Walls. — For  this  purpose  choice  should  be  made  of 


CAVITY  LINING  IN  RESPECT  TO  PROXIMITY  OF  THE  PULP.   259 

zinc  phosphate,  since  it  has  the  required  strength  and  enters  into  the 
necessary  adhesive  union  with  the  margins  to  give  the  required  secur- 
ity. The  layer  should  be  kept  within  the  extreme  outer  border  of  the 
cavity,  to  permit  the  metal  filling  to  overlay  the  margin  of  the  enamel. 
When  the  cavity  is  deep  the  retaining  groove  may  be  formed  in  the 
cement. 

A  general  summary  of  cavity  lining  is,  that  this  procedure  is  required 
in  proportion  to  the  difficulty  of  effective  approach,  and  for  the  safe 
treatment  of  teeth  below  the  average  of  structural  quality. 


CHAPTER   XI. 

TREATMENT  OF  FILLINGS  WITH  RESPECT  TO  CONTOUR, 
AND  THE  RELATION  OF  CONTOUR  TO  PRESERVATION 
OF  THE  INTEGRITY  OF  APPROXIMAL  SURFACES. 

By  S.  H.  Guilford,  D.  D.  S.,  Ph.  D. 


The  treatment  of  a  cavity  of  decay  by  filling  must  have  a  twofold 
object  in  order  to  subserve  its  best  purposes  :  first,  the  restoration  of 
the  affected  part  to  a  healthy  condition  ;  and  second,  the  prevention  as 
far  as  possible  of  a  recurrence  of  the  lesion. 

The  first  is  accomplished  by  the  removal  of  all  disintegrated  tissue 
and  the  perfect  filling  of  the  cavity  with  a  suitable  and  durable  material. 
The  second  demands  for  its  success  a  proper  understanding  of  the  cha- 
racter of  the  surfaces  operated  upon  and  their  mechanical  and  physio- 
logical relations.  While  the  simple  filling  of  a  cavity,  if  properly 
done,  will  generally  prevent  the  extension  of  decay  on  exposed  surfaces, 
the  same  operation  on  surflices  less  favorably  situated  may  utterly  fail 
to  subserve  the  desired  end. 

The  contiguity  of  the  approximal  surfaces  of  teeth  greatly  favors 
the  retention  of  food  and  the  harboring  of  micro-organisms,  while  at 
the  same  time  it  prevents  the  free  cleansing  movement  of  saliva  be- 
tween them.  For  these  reasons  such  surfaces,  though  originally  per- 
fect in  their  continuity,  are  attacked  by  caries  more  frequently  than  any 
others,  except  the  occlusal  surfaces  where  continuity  is  broken  by  fis- 
sures and  pits.  When  once  affected  by  caries,  their  restoration  by  fill- 
ing is  difficult  owing  to  their  inaccessibility,  and  while  the  operations 
on  this  account  often  lack  the  perfection  that  would  otherwise  be  secured 
and  the  fillings  consequently  fail,  the  recurrence  of  decay  is  more  largely 
due  to  the  same  influences  that  brought  about  the  initial  lesion. 

This  being  the  case  it  is  obvious  that  the  original  conditions  must  be 
changed  if  immunity  from  future  decay  is  to  be  expected.  This 
principle  was  early  recognized  and  the  first  attempt  to  alter  the  con- 
ditions was  by  filing  or  cutting  the  approximal  surfaces  so  as  to  free 
them  from  contact,  on  the  principle  of  '*  no  contact,  no  decay."  Where 
all  of  the  teeth  were  thus  separated  immunity  from  decay  was  generally 
secured,  although  at  the  cost  of  great  loss  of  masticating  surface,  much 

261 


262  THE  SELF-CLEANSING  SPACE. 

disfiguromont,  and  subsequent  serious  injury  to  the  gum  and  peri- 
cementum. 

Where  only  an  occasional  space  of  this  character  was  made,  the 
ojKM-ation  ])roved  a  failure  becausein  a  short  time,  through  the  pressure 
of  adjoining  teeth  and  altered  occlusion,  the  mutilated  teeth  would  again 
be  brought  into  contact  and  the  opportunity  for  decay  be  increased  a 
hundredfold.  With  the  recurrence  of  decay,  cutting  or  filing  would 
again  have  to  be  resorted  to  until  but  little  of  the  teeth  remained,  and 
they  were  eventually  lost.  On  account  of  its  unfortunate  results  the 
method  was  for  a  time  abandoned,  but  in  1870  it  was  revived  in  a 
modified  form  through  the  teachings  and  writings  of  Dr.  Robert 
Arthur.  His  method  consisted  in  altering  the  form  of  the  approximal 
surfaces  of  teeth  by  filing  or  grinding  so  as  to  chang,e  the  point  of  ap- 
proximal contact  from  near  the  occlusal  surface  to  near  the  cervical 
margin.  This  not  only  changed  the  normally  convex  approximal  sur- 
face into  a  flat  or  plane  one,  but  was  also  supposed  to  free  it  from  further 
liability  to  decay  by  preventing  the  retention  of  food  debris  and  render- 
ing the  surfaces  and  spaces  "  self-cleansing."  The  method  was  measur- 
ably adopted  by  numbers  of  conscientious  practitioners  as  a  means  of 
obviating  a  difficulty  hitherto  unsuccessfully  combated.  In  a  short 
time,  however,  it  was  discovered  that  its  promise  of  success  was  not 
being  realized,  and  it  was  also  gradually  abandoned.  Its  failure  was 
due  to  its  being  wrong  in  principle,  for,  while  it  seemed  to  offer  tem- 
porary relief,  its  after  results  were  most  disastrous. 

By  leaving  a  shoulder  near  the  cervical  margin  the  point  of  contact 
was  simply  transferred  from  one  point  to  another  with  the  residt  that 
the  latter  point  was  far  more  liable  to  caries  than  the  former  one,  owing 
to  its  position.  More  than  this,  the  exposed  dentin  on  the  cut  surfaces^ 
lacking  the  natural  protection  of  the  enamel  covering,  was  apt  to  be 
sensitive,  and  the  food  crowding  into  the  space  and  pressing  upon  the 
gum  rendered  it  hypersensitive  and  eventually  caused  its  recession. 
The  discomfort  following  this  unnatural  operation,  together  with  the 
increased  liability  to  decay  resulting  from  it,  were  sufficient  to  condemn 
the  method  and  cause  its  abandonment. 

These  failures  to  secure  freedom  from  decay  by  an  unnatural  altera- 
tion of  the  forms  of  approximal  surfaces  led  to  a  more  careful  investi- 
gation of  the  causes  responsible  for  its  recurrence  on  these  surfaces,  and 
the  gradual  adoption  of  more  rational  and  scientific  methods  for  its  pre- 
vention. It  was  apparent  to  even  the  most  casual  student  of  compara- 
tive dental  anatomy  that  the  number  and  kinds  of  teeth  found  in  the 
jaws  of  man,  their  arrangement  in  the  arches,  and  their  general  form 
were  all  such  as  to  best  subserve  the  wants  and  needs  of  the  individual, 
but  the  more  minute   points  of   their  external  anatomy,  their  inter- 


NORMAL  CONTOUR  IN  RELATION  TO  CARIES.  263 

dependence  and  relation  to  one  another,  and  the  part  played  by  the  fluids 
of  the  month  in  the  causation  of  caries  under  both  original  and  changed 
conditions,  had  not  previously  been  carefully  inquired  into.  Under  the  old 
belief  that  contact  caused  decay  it  was  thought  that  decay  upon  approxi- 
mal  surfaces  always  began  at  the  point  of  contact  and  that  this  was  due 
to  the  fermentative  changes  occurring  in  food  debris  retained  at  this 
point.  Investigation  proved,  however,  that  the  points  of  contact  be- 
tween teeth  were  not  only  free  from  decay,  but  more  or  less  polished 
from  slight  motion  of  the  teeth  in  their  sockets,  and  that  approximal 
decay  always  began  just  above  the  contact  point,  that  is,  slightly  nearer 
the  gum ;  also  that  it  could  occur  nearly  as  readily  without  the  presence 
of  food  as  with  it. 

It  was  further  noted  that  the  normal  contact  of  teeth  on  their 
approximal  surfaces,  which  was  formerly  supposed  to  be  essential  only 
for  mutual  support,  was  equally  necessary  for  the  protection  of  the 
tender  gum  tissue  from  injurious  pressure  of  food  in  mastication. 

Finally  it  was  observed  that  those  portions  of  the  crown  of  a  tooth 
that  were  beneath  the  gum  margin  or  those  above  it  that  were  constantly 
covered  by  saliva  (as  on  the  approximal  surfaces  near  the  gum)  were 
always  free  from  the  beginnings  of  decay,  and  that  the  approximal  and 
buccal  or  lingual  surfaces,  when  faultless  in  structure,  were  first  attacked 
by  caries  on  a  line  corresponding  with  the  point  to  which  the  fluids  of 
the  mouth  usually  rose.  An  explanation  of  this  peculiarity  was  soon 
found  in  the  fact  that  the  saliva  is  usually  alkaline  and  consequently 
protective  of  the  parts  covered  by  it,  but  at  its  surface,  in  a  state  of 
rest  (as  in  sleep),  this  condition  of  alkalinity  is  changed  to  one  of 
acidity — the  calcium  salts  are  dissolved  and  decay  is  begun. 

As  a  result  of  the  foregoing  observations  and  investigations  it 
became  apparent  to  the  mass  of  conscientious  workers  in  the  field  of 
operative  dentistry  :  1st.  That  the  natural  form  or  outline  of  each  tooth 
was  the  best  for  its  particular  function,  and  that  to  materially  alter  it  was 
to  lessen  its  usefulness  and  hasten  its  loss.  2d.  That  contact  of  ad- 
joining teeth  was  essential  both  to  the  comfort  of  the  individual  and 
the  durability  of  the  organs,  3d.  That  inasmuch  as  the  teeth  originally 
decay  in  spite  of  their  natural  form  and  contact,  some  plan  would  have 
to  be  devised  by  which,  in  their  repair  after  decay,  liability  to  a  recur- 
rence of  caries  would  be  greatly  lessened  if  not  entirely  prevented. 

To  fulfill  these  requirements  there  was  but  one  course  left  to  pursue, 
namely,  to  fill  approximal  cavities  in  such  a  way  as  to  restore  the 
original  contour  of  the  surface,  and,  in  all  cases  where  the  extent  of 
decay  was  sufficient  to  warrant  it,  to  extend  the  cavities  so  far  over  nj)on 
the  buccal  and  liny-ual  surfiices  as  to  briup;  the  enamel  mary;ins  within 
the  range  of  protective  influences. 


264  CAPILLARITY  OF  APPROXIMAL  SURFACES. 

The  rationale  of  (H'i<rinal  and  ivcurrino^  decay  upon  approximal 
surfaces  is  readily  made  apparent  by  considering  certain  facts  and  prin- 
ciples of  physics. 

Wh(Mi  a  tube  is  inserted  in  a  li([uid  capable  of  wetting  its  surface 
the  liquid  will  rise  to  a  higher  level  within  the  tube  than  the  surface 
level  of  the  surrounding  liquid.  This  phenomenon  is  known  as  capil- 
lary attraction,  and  is  explained  upon  the  principle  of  "  surface  tension 
of  liquids."  If,  instead  of  a  tube,  two  rounded  or  flat  plates  are  im- 
mersed in  the  licpiid,  the  same  rising  of  the  fluid  between  them  will 
be  noticed.  The  smalh^r  the  tube,  or  the  nearer  the  two  plates  are 
together,  the  higher  will  the  liquid  rise. 

Applying  the  princij)les  governing  these  facts  to  the  teeth  and  con- 
sidering them  as  bodies  immersed  in  a  liquid  (saliva),  it  will  readily  be 
seen  that  if  the  appnjximal  surfaces  of  the  teeth  were  parallel  and 
close  together  the  saliva  would  rise  to  a  higher  level  between  them  and 
cover  more  tooth  surface  than  if  they  stood  farther  apart,  and  being  re- 
tained in  this  narrow  space  with  little  opportunity  for  motion  the  saliva 
would  soon  assume  an  acid  character  and  destruction  of  the  tooth  tissue 
begin.  This  is  exactly  what  takes  place  upon  approximal  surfaces 
made  flat  by  filing,  and  will  occur  whether  fillings  have  been  placed 
in  such  surfaces  or  not. 

Normally,  however,  the  crowns  of  the  human  teeth  are  more  or  less 
convex  upon  their  approximal  surfaces  and  touch  each  other  only  at  the 
point  of  their  greatest  transverse  diameters,  which  is  near  to  and  just 
above  the  occlusal  surfice.  From  this  point  their  diameters  gradually 
become  less  until  they  reach  the  cervical  border,  where  they  are  smallest. 
This  leaves  a  triangular  interdental  space  with  the  base  of  the  tri- 
angle at  the  gum,  as  shown  in  Fig.  221,  in  which  the  saliva  will  rise  but 

a  short  distance  owing  to  the  separation  near  the 
Fig  "^21  .  ^ 

gum  and  the  consequent  lessening  of  the  capil- 
lary attraction.  For  this  reason  teeth  preserving 
their  normal  forms  are  less  liable  to  approximal 
decay  than   they   could   possibly  be    under   any 

Showing  nornicil  eonUct  of        other  COuditionS. 

teeth. 

The  earliest  treatment  of  approximal  sur- 
faces with  a  view  to  the  prevention  of  caries  consists  in  gaining  access 
to  them  by  wedging,  and  if  found  to  be  superficially  affected  by  caries 
the  removal  of  the  injured  structure  and  the  perfect  polishing  of  the 
surfaces. 

When  cavities  of  moderate  size  are  discovered  they  should  be  care- 
fully prepared  and  filled,  preserving  the  original  contour  as  far  as 
possible.  Decay  may  recur,  but  it  is  less  likely  to  do  so  with  advan- 
cing age,  increased  density  of  tissue,  and  proper  prophylactic  treatment. 


CONTOURING  AS  A  PROTECTIVE  MEASURE.  265 

Where  the  decay  is  of  larger  extent,  however,  we  have  it  in  our  power 
to  make  such  physical  change  in  the  parts  affected  as  to  render  future 
immunity  from  decay  reasonably  certain. 

First,  it  is  necessary  to  separate  the  teeth  well  by  wedging,  to  so 
enlarge  the  cavities  as  to  bring  their  lateral  margins  well  out  upon  the 
lingual  and  buccal  surfaces,  and  to  extend  the  cervical  margins  of  the 
cavities  down  to  or  beneath  the  free  margin  of  the  ^um. 

Xext,  the  fillings  must  be  carefully  inserted,  built  out  to  fully 
restore  the  original  contour,  and  most  perfectly  finished.  When  this 
has  been  done  and  the  teeth  have  returned  to  their  former  positions 
the  approximal  surfaces  will  be  in  a  better  condition  to  resist  the  influ- 
ences of  decay  than  they  originally  were,  for  any  changes  in  the  char- 
acter of  the  saliva  cannot  affect  the  gold,  and  while  the  cervical  border 
of  the  filling  is  protected  by  being  constantly  covered  by  saliva  the 
lateral  borders  are  so  far  out  upon  their  respective  surfaces  as  to  be  sub- 
ject to  the  cleansing  influences  of  the  lips  and  tongue. 

In  addition  to  this,  and  scarcely  less  important,  the  restoration  of 
•contour  on  the  approximal  surfaces  affords  normal  protection  to  the 
tender  gingivae  by  preventing  the  lodgment  and  pressure  of  food  upon 
them. 

The  contour  method  of  filling,  based  as  it  is  upon  physiological, 
anatomical,  and  mechanical  principles,  has  become  the  accepted  method 
of  operating.  Experience  has  proved  it  to  be  the  only  rational  method 
of  treatment  of  approximal  surfaces,  for  by  it  we  secure  all  the  desir- 
able conditions  of  preservation  of  the  natural  outline  of  the  teeth, 
necessary  contact,  immunity  from  future  decay,  and  protection  of  the 
gum  margins.  Its  practice  involves  some  sacrifice  of  healthy  tooth 
structure  along  the  buccal  and  lingual  aspects,  as  well  as  greater  ex- 
penditure of  time  in  filling  and  finishing,  but  the  results  compensate 
for  both  of  these. 

To  properly  perform  the  operation  of  filling  and  restoration  of 
approximal  contour  requires  not  only  manipulative  skill  of  a  high 
order,  but  also  an  artistically  trained  eye  in  order  that  the  restoration 
may  in  all  respects  correspond  both  in  extent  and  form  to  the  original 
outline  of  the  tooth ;  both  of  these  requisites  will  be  acquired  through 
frequent  repetition.  In  certain  cases,  as  where  the  teeth  originally  were 
not  quite  in  contact,  the  contour  may  be  advantageously  exaggerated  in 
order  to  close  the  space,  but  it  should  never  be  less  than  normal  or  the 
result  will  not  be  satisfactory. 

In  the  filling  of  an  approximal  surface  next  to  a  space,  as  where  a 
tooth  has  been  lost,  the  necessity  for  full  restoration  of  contour  does 
not  exist  and  is  not  absolutely  demanded,  although  a  more  artistic  result 
is  secured  by  its  performance  in  all  cases. 


CHAPTER    XII. 

THE    OPERATION    OF    FILLING    CAVITIES  WITH  METALLIC 
FOILS  AND  THEIR  SEVERAL   MODIFICATIONS. 

By  Edwix  T.  Darby,  D.  D.  S.,  M.  D. 


In  the  selection  of  a  filling  material  the  operator  should  consider  the 
character  of  the  secretions  of  the  oral  cavity,  the  position  of  the  tooth 
to  be  filled,  the  extent  of  the  diseased  area,  the  physical  structure  of  the 
tooth,  and  the  strength  of  the  cavity  walls.  A  filling  material  must 
possess  certain  inherent  qualifications,  the  most  important  of  which  are 
adaptability,  indestructibility,  non-conductivity,  hardness,  absence  of 
shrinkage,  harmony  of  color,  and  ease  of  manipulation.  All  of  these 
are  not  to  be  realized  in  any  one  material,  and  yet  some  of  the  more 
important  are  to  be  found  in  a  single  metal  or  in  a  combination  of 
metals. 

Lead  possesses  the  quality  of  softness  and  is  easy  of  adaptation  but 
is  readily  oxidized  when  exposed  to  the  air  or  the  secretions  of  the 
mouth.  Likewise  tin  possesses  characteristics,  such  for  instance  as  duc- 
tility and  softness,  low  conducting  power,  and  the  ease  with  which  it 
may  be  manipulated,  which  place  it  in  the  front  rank  as  a  preservative 
of  carious  teeth,  but  it  is  inharmonious  in  color,  and  its  very  softness, 
which  is  so  desirable  in  manipulation,  is  an  obstacle  to  its  use  upon 
surfaces  where  there  is  much  attrition.  The  zinc  phosphates,  which  are 
composed  of  zinc  oxid  and  phosphoric  acid  in  solution,  form  a  com- 
bination which  at  first  attracted  the  favorable  attention  of  the  dental 
surgeon  as  possible  substitutes  for  metallic  foil  fillings.  They  possess, 
owing  to  their  plasticity,  ease  of  manipulation,  harmony  of  color,  com- 
parative non-conductivity,  and  absence  of  shrinkage,  many  desirable 
qualities,  but  are  lacking  in  one  essential  qualification,  namely,  inde- 
structibility. 

Gold. 

Gold,  which  has  been  used  for  about  a  century,  has  fulfilled  in  a 
more  marked  degree  than  any  other  material  or  combination  of  materials 
the  requirements  sought  for  in  a  filling  for  carious  teeth.  It  has  one  or 
tvvo  objectionable  features,  such  as  high  conductivity  of  heat  and  inhar- 
monious color. 

267 


268  THE  OPERATION  OF  FILLING   CAVITIES. 

Too  much  stress  cannot  be  laid  upon  the  question  of  its  purity  if  the 
best  results  are  to  be  obtained  from  its  use.  While  it  is  claimed  by 
manufacturers  of  dental  gold  foil  that  their  ])roducts  are  absolutely  free 
from  alloy,  it  is  nevertheless  true  that  but  few  sju'cimens  of  dental  foil 
show  a  fineness  above  999.  If  this  standard  Avere  always  attained  the 
o})erator  would  have  little  cause  for  complaint.  So  small  a  percentage 
of  alloy  as  1  in  1000  would  not  materially  affect  the  working  qualities 
of  the  product,  but  when  this  is  increased  to  4  or  6  parts  per  1000  it 
manifests  itself  by  harshness  and  intractability  under  the  instrument. 

Great  care  should  be  exercised  in  the  preparation  of  the  foil,  since 
so  much  depends  upon  its  purity  and  cleanliness.  For  a  detailed 
description  of  the  process  of  manufacture,  from  the  ingot  to  the  beaten 
and  annealed  foil,  the  reader  is  referred  to  an  article  by  a  practical  foil- 
maker.^ 

In  former  times  the  dental  surgeon  w'as  restricted  to  one  form 
of  gold  for  filling.  This  was  foil  ranging  in  thickness  from  4  to  10 
grains  to  the  leaf,  but  as  the  requirements  of  the  operator  broadened 
the  art  of  manufacture  increased,  and  new  preparations  were  offered, 
until  to-day  the  most  fastidious  can  find  such  as  will  please  his  fancy  : 
foils  ranging  in  weight  from  4  to  120  grains  to  the  leaf;  cylinders  of 
various  sizes  and  composed  of  non-cohesive  and  semi-cohesive  foil ;  cohe- 
sive blocks  prepared  for  use  ;  rolled  gold,  varying  in  thickness  from  No. 
30  to  120,  and  crystal  gold  possessing  great  cohesive  properties.  These 
are  the  more  important  forms  in  which  gold  is  offered  the  oj^erator  at 
the  present  time. 

Before  entering  upon  a  description  of  the  classes  of  cases  where  each 
of  these  seems  best  adapted,  it  may  be  well  to  describe  somewdiat  in 
detail  the  peculiar  qualities  which  each  form  of  gold  presents  when 
subjected  to  clinical  use. 

Soft  or  Non-cohesive  Foil, — Prior  to  1854,  wdien  Dr.  Robert 
Arthur  discovered  and  promulgated  the  desirability  of  cohesive  foil  in 
certain  cases,  the  operator  used  gold  which  possessed  very  low  cohesive 
properties.  Used  as  it  then  was,  in  the  form  of  large  rope,  tape,  or  as 
cylinders,  the  property  of  cohesion  would  have  been  a  serious  objection, 
since  there  would  be  constant  danger  of  the  mass  clogging  and  bridging 
in  the  cavity,  and  the  cause  of  many  unfilled  places  along  the  cavity 
walls. 

The  terms  soft  and  hard,  when  used  to  designate  the  kind  of  gold,  are 
misleading,  since  all  gold  foil  prepared  from  pure  gold  or  gold  that  is 
nearly  pure  possesses  great  softness  under  the  instrument.  The  distin- 
guishing characteristics  between  the  two  kinds  of  gold  are  the  inability 
to  make  a  certain  kind  of  foil  cohesive  when  exposed  to  a  reasonable 

^  American  System  of  Dentistry,  vol.  iii.  p.  839. 


GOLD.  269 

degree  of  heat,  and  the  ability  to  render  another  make  of  equal  purity 
cohesive  by  the  application  of  a  similar  degree  of  heat.  It  has  been 
claimed  by  some  manufacturers  of  dental  gold  foils  that  they  are  able 
to  procure  from  the  same  ingot  samples  of  non-cohesive,  semi-cohesive, 
and  extra-cohesive  gold,  attaining  these  physical  properties  of  the  mate- 
rial without  alloying  with  other  metals.  This  has  led  to  the  belief 
that,  since  absolutely  pure  gold  possesses  inherent  cohesive  properties, 
some  metallic  salt  or  other  foreign  substance  has  been  deposited  upon 
the  surface  of  the  leaf  of  non-cohesive  foil  which  has  the  power  of  pre- 
venting the  union  of  the  surfaces  of  the  foil  when  contact  is  sought. 
It  has  been  surmised  that  a  thin  film  of  iron  has  been  deposited  upon 
the  surfaces  of  the  leaf  of  non-cohesive  foil,  for  the  reason  that  if  a 
leaf  of  such  foil  be  melted  into  a  globule,  it  presents  a  reddish  brown 
appearance,  Avhich  is  not  true  of  the  leaf  of  cohesive  foil  when  melted 
as  above. 

Much  of  the  so-called  non-cohesive  foil  offered  for  sale  is  not, 
strictly  speaking,  of  this  variety,  as  the  application  of  moderate  heat 
will  render  it  quite  cohesive.  It  possesses  the  softness  peculiar  to  pure 
gold  foil,  but  it  should  not  be  classed  with  the  variety  which  does  not 
weld  with  other  particles  of  the  same  metal  except  when  subjected  to 
great  heat. 

It  has  been  claimed  by  some  that  non-cohesive  foil  has  no  place  in 
dental  practice — that  any  tooth  which  can  be  filled  with  gold  may  be 
filled  with  cohesive  foil.  This  statement  may  be  true  in  the  main,  but 
it  is  also  true  that  many  teeth  having  strong  cavity  walls  can  be  just  as 
well  filled  where  a  large  portion  of  the  filling  is  made  with  non-cohe- 
sive foil,  and  with  a  great  saving  of  time.  Adaptation,  not  hardness, 
constitutes  the  saving  quality  in  cavity  filling. 

As  most  non-cohesive  foil  is  prepared  in  the  form  of  sheets  and 
is  placed  in  books  containing  one-eighth  of  an  ounce,  the  operator  is 
compelled  to  prepare  it  in  some  form  suitable  for  introduction  to  the 
cavity.  The  size  and  shape  of  the  cavity  will  be  some  guide  as  to  the 
best  method  of  preparing  the  gold.  The  narrow  tape,  the  mat,  the 
tightly  rolled  cylinder,  and  the  roll  or  rope  are  the  forms  best  adapted 
for  the  use  of  non-cohesive  gold  foil. 

The  tape  is  best  made  by  taking  one-half  or  one-third  of  a  leaf  of 
No.  4  or  No.  5  foil,  laying  it  upon  a  table  napkin  of  medium  size  folded 
square  as  it  comes  from  the  laundry ;  the  napkin  is  then  taken  in  the 
palm  of  the  left  hand,  and  the  foil  spatula  is  placed  in  the  middle  of 
the  piece  of  foil ;  the  hand  is  then  closed  tightly,  thus  folding  the  nap- 
kin, likewise  the  foil,  upon  the  sides  of  the  spatula.  This  process  is 
repeated  until  the  tape  is  one-eighth  or  one-sixteenth  inch  in  width 
(Fig.  222). 


270 


THE  OPERATION  OF  FILLING   CAVITIES. 


If  mats  are  required,  the  foil  may  be  folded  twiee  or  three  times  and 
then  folded  lengthwise  upon  itself  until  mats  of  any  thickness  are  pro- 
duced, as  shown  in  Fig.  223. 

When  non-cohesive  cylinders  are  desired,  it  is  better  for  the  operator 
to  make  them  rather  than  depend  upon  the  ready-made  ones  as  prepared 
by  the  manufacturer,  since  these  are  usually  loosely  rolled  and  more  or 
less  cohesive.     The  tape  is  quickly  made  into  the  cylinder  by  rolling  it 


Fig.  222. 


Fig.  223. 


iapcK  of  giili-i  lull. 


Mats  of  gold  foil. 


upon  a  five-sided  broach  to  the  desired  size.  The  depth  of  the  cavity 
is  a  guide  to  the  width  of  the  tape,  and  the  width  of  the  tape  determines 
the  length  of  the  cylinder.  These  should  be  somewhat  longer  than  the 
depth  of  the  cavity.  The  manner  of  introducing  and  condensing  will 
be  described  later  when  special  cases  are  under  consideration. 

The  roll,  or  "  rope  "  as  it  was  formerly  called,  is  made  in  the  following 
way  :  A  leaf  or  half  leaf  or  a  third  of  a  leaf  of  foil  is  rolled  between  the 

Fifi.  224. 


JJevice  fur  rolling  gold  foil. 

thumb  and  finger  until  a  roll  of  moderate  density  is  obtained.  As  foil 
is  contaminated  by  contact  with  the  moisture  and  surface  impurities  of 
the  hands,  it  is  better  to  avoid  such  contact  as  much  as  possible.  This 
can  be  completely  attained  by  rolling  it  upon  the  little  device  shown  in 
Fig.  224.  Any  operator  can  make  one  of  these  by  taking  two  pieces  of 
thin  board,  such  for  instance  as  the  lid  of  a  cigar  box,  and  fastening 
to  the  two  pieces  with  glue  a  piece  of  white  kid  about  eight  inches  in 


GOLD.  271 

length,  and  in  width  equal  to  the  sheet  of  foil.  Two  little  drawer- 
knobs  of  ebony  should  be  inserted  into  the  centre  of  each  of  the  pieces 
of  board.  These  act  the  part  of  handles  for  holding  the  appliance. 
The  gold  is  then  placed  upon  the  kid  strip  between  the  two  pieces  of 
board,  and  by  bringing  the  two  surfaces  of  the  kid  in  contact  the  foil  is 
rolled  between  them.  The  undressed  surface  of  the  kid  should  be  the 
•one  upon  which  the  gold  is  rolled.  Ropes  thus  made  may  be  cut  in 
lengths  to  suit  the  size  of  the  cavity  to  be  filled,  and,  as  gold  thus  pre- 
pared has  great  softness  and  ease  of  adaptation,  it  may  be  inserted  in 
quite  large  pieces  if  plenty  of  condensing  force  be  applied  to  it. 

Cohesive  Gold  Foil. — All  gold  which  has  been  refined  by  any  of 
the  ordinary  methods  and  is  in  a  pure  state  may  be  said  to  be  cohesive. 
Nor  is  absolute  freedom  from  alloy  an  absolute  necessity.  It  has  been 
shown  that  softness  is  dependent  upon  purity,  but  a  foil  may  contain 
quite  a  percentage  of  silver,  copper,  palladium,  or  zinc,  and  yet  its 
cohesion  may  not  be  impaired.  It  may  also  be  alloyed  or  combined 
with  platinum  and  not  lose  its  cohesive  properties.  It  is,  however, 
desirable  that  cohesive  gold  be  pure,  since  the  smallest  percentage  of 
alloy  destroys  its  softness. 

When  two  sheets  or  laminae  of  freshly  annealed  foil  are  brought  into 
contact  and  slight  pressure  is  applied,  they  form  a  permanent  union  and 
are  practically  inseparable.  It  is  this  property  in  gold  to  which  the 
term  cohesive  has  been  applied.  But  this  property  is  soon  lost  by  the 
occlusion  of  gases  or  impurities  of  any  kind  which  may  be  deposited 
upon  the  surface  of  the  gold.^ 

Experiments  have  demonstrated  the  fact  that  if  the  gold  be  sub- 
jected to  the  fumes  of  ammonia,  hydrogen,  hydrogen  carbid,  hydrogen 
phosphid,  or  sulfurous  acid  gas  its  cohesive  property  is  quickly  de- 
stroyed, but  this  property  may  be  restored  by  heat  except  in  the  case 
of  sulfur  or  phosphorus  fumes.  Hence  the  importance  of  excluding 
the  gold  as  much  as  possible  from  the  atmosphere,  especially  during  the 
Avinter  months  when  gases  arising  from  the  combustion  of  coal  are  most 
liable  to  be  present  in  the  operating  room. 

Dr.  Black  has  shown  that  ammoniacal  gas  has  the  power  to  prevent 
the  deleterious  influence  of  other  gases,  and  recommends  that  the  foil 
be  subjected  to  the  influence  of  carbonate  of  ammonia  by  keeping  it  in 
a  drawer  with  a  bottle  of  that  salt. 

The  advantages  of  cohesive  foil  cannot  be  overestimated.  With  its 
introduction  in  1855  began  a  new  era  in  the  possibilities  of  saving  cari- 
ous teeth.  Operations  which  were  deemed  impossible  by  the  use  of 
non-cohesive  foil  were  made  comparatively  easy  by  the  intelligent  use 
of  cohesive  foil.     The  restoration  of  broken-down  or  badly  decayed 

^  G.  V.  Black,  Dental  Cosmos,  vol.  xvii.  p.  138. 


272 


THE  OPERATION  OF  FILLING   CAVITIES. 


teeth  became  the  common  practice  in  the  hands  of  the  skillful,  and  mod- 
ern mi^thods  of  practice  coupled  with  intelligent  use  of  this  form  of 
gold  have  made  it  possible  for  the  operator  of  modern  times  to  do  that 
which  the  earlier  practitioner  deemed  impossible. 

The  beginner,  however,  must  not  lose  sight  of  the  fact  that  cohesive 
foil  cannot  be  worked  after  the  same  methods  as  non-cohesive  foil.  To 
use  cohesive  foil  in  the  form  of  mats  or  cylinders  or  in  tightly  rolled 
ropes  would  mean  inevitable  failure  in  adaptation.  The  very  property 
which  renders  it  valuable  in  the  restoration  of  broken-down  teeth  and  in 
surfacing  is  the  one  which  would  condemn  it  if  used  carelessly  in  the^ 
interior  of  inaccessible  cavities.  Non-cohesive  gold  may  be  introduced 
into  a  well-shaped  cavity  in  large  masses,  and  because  of  its  softness 
and  ease  of  adaptation  may  be  made  to  touch  all  points  of  the  cavity 
walls  if  persistent  pressure  be  applied.  On  the  contrary,  cohesive  foil 
should  be  introduced  in  small  pieces,  the  first  of  which  should  be  Avell 
anchored  in  a  retaining  pit  or  groove  and  each  subsequent  piece  welded 
thereto. 

There  are  several  modes  of  preparing  the  beaten  cohesive  gold  foil 
for  the  cavity,  and  good  results  are  obtained  by  either  of  the  following 
methods. 

A  loosely  rolled  rope  made  of  a  quarter  sheet  of  No.  4  or  5  foil 
may  be  cut  into  lengths  varying  from  one-eighth   to  one-quarter  of 

Fig.  225. 


I 

I 


I 
I 

I    ■ 

I 


i  i 

I 


Ribbons  and  strips. 


an  inch,  and  after  annealing  carried  to  the  cavity  upon  the  point  of 
the  plugging  instrument.     Or  a  leaf  may  be  folded  with  a  spatula  four 


GOLD.  273 

times,  making;  a  broad  ribbon,  which  may  be  cut  either  lengthwise  or 
crosswise  of  the  ribbon  in  pieces  one-sixteenth  or  one-eighth  of  an  inch 
in  width  (see  Fig.  225).  This  is  a  very  convenient  manner  of  working 
cohesive  gold.  Or  the  heavier  foil  up  to  No.  20  or  Xo.  30  in  thickness 
may  be  cut  in  strips  of  a  single  thickness  and  of  the  widths  above  indi- 
cated, and  after  annealing  may  be  packed  into  the  cavity — the  essential 
idea  being  ever  in  mind,  that  but  a  small  quantity  of  the  gold  shall  be 
under  the  instrument  at  a  given  time.  Cohesive  gold  which  has  been 
rolled  instead  of  beaten  to  the  desired  thickness  is  much  prized  by  some. 
It  has  been  asserted  that  greater  softness  is  obtained  when  gold  has  been 
thus  ]ireparcd.  Such  gold  should  not  be  more  than  No.  20  or  No.  30 
in  thickness  to  insure  the  best  results.  It  should  be  cut  in  narrow 
strips  and  after  annealing  be  folded  back  and  forth  as  rapidly  only  as 
each  previous  fold  has  been  well  conden^^ed.  Good  results  are  only 
attainable  if  each  lamina  be  thoroughly  welded. 

The  loosely  rolled  cylinders  and  blocks  which  are  prepared  by  some 
dealers  and  offered  as  cohesive  gold  are  usually  but  slightly  cohesive, 
and  if  used  in  this  form,  without  re-annealing,  may  be  packed  in  the 
interior  of  cavities  without  danger  of  clogging,  but  if  freshly  annealed 
they  are  contraindicated,  since  there  is  more  or  less  danger  of  imper- 
fect union  of  all  particles  of  the  gold.  It  is  questionable  whether  the 
larger  sizes  are  admissible  when  the  filling  extends  beyond  the  cavity 
walls  and  great  solidity  is  an  essential  factor. 

Crystal  Gold. — This  form  of  gold  was  introduced  by  Mr.  A.  J. 
"Watts  in  1853,  and  as  prepared  at  the  present  time  is  one  of  the  best 
preparations  of  cohesive  gold.  When  first  brought  out  the  method  of 
manufacture  was  faulty,  since  it  was  difficult  or  impossible  to  rid  the 
spongy  mass  of  nitric  acid  which  was  used  in  its  preparation,  but  since 
Mr.  AVatts  adopted  electrolysis  instead  of  chemical  precipitation  the 
objectionable  features  no  longer  exist.  Gold  thus  prepared  manifests 
great  cohesive  properties,  and  when  used  with  care  as  beautiful  opera- 
tions can  be  made  with  this  gold  as  with  any  form  of  cohesive  foil.  The 
operator  should  not  lose  sight  of  the  fact  that  the  gold  is  to  be  intro- 
duced into  the  cavity  in  small  quantities.  Should  failure  attend  its 
use,  it  would  doubtless  be  from  the  attempt  to  introduce  it  too  rapidly. 
Gold  of  this  variety  comes  in  bricks  containing  one-eighth  of  an  ounce 
each,  and  is  either  torn  apart  in  irregnlar-shaped  pieces  or  cut  by  means 
of  a  razor  into  small  cubes.  This  gold  should  be  excluded  as  much  as 
possible  from  the  atmosphere  and  when  used  should  be  well  annealed, 
although  when  recently  made  it  is  quite  cohesive.  There  is  no  prepara- 
tion of  gold  better  adapted  for  starting  fillings  in  shallow  or  irregular 
cavities,  or  for  surfacing  fillings.  Many  operators  make  use  of  it 
always  for  starting  and  for  finishing  fillings. 

18 


274  THE  O  PER  A  r ION  OE  ETLLTNG   CAVITIES. 

Crystal  Mat  Gold. — This  is  anotlior  form  of  crystal  J2:<'l<lj  ini<l 
diifcrs  from  that  previously  (l('S(;ril)<'(l  in  that  it  presents  a  more  eomj)act 
form,  the  crystals  a})pearing  smaller  and  matted  to<i^ether.  It  breaks 
and  crumbles  under  the  instrument  to  a  greater  defrree  than  the  other, 
and  possesses  no  desirable  qualities  which  the  otlua*  has  not.  If  it  has 
any  merit  it  is  for  tinishing  the  fillings  upon  occlusal  surfaces,  or  such 
surfaces  as  are  easy  of  access,  or  it  may  be  used  in  conjunction  with 
amalgam. 

Gold  and  Platinum. — This  form  of  gold  has  found  much  favor 
with  many  practitioners  for  the  restoration  of  incisal  edges,  or  where 
for  any  reason  great  hardness  of  surface  is  desired. 

An  ingot  or  bar  of  pure  gold  and  one  of  platinum  are  "  sweated  " 
together  and  then  rolled  to  the  desired  thinness,  usually  about  that  of 
No.  20  or  No.  JiO  foil.  It  is  then  cut  into  narrow  strips,  freshly  an- 
nealed and  used  after  the  same  manner  as  heavy  foil.  The  commingling 
of  the  platinum  with  the  gold  gives  the  filling  a  tint  more  nearly  the 
shade  of  the  tooth,  and  for  this  reason  it  is  much  used  upon  labial  sur- 
faces and  in  mouths  where  the  teeth  are  much  exposed. 

Gold  thus  combined  with  platinum  is  much  more  rigid  than  gold 
alone, and  is  contraindicated  for  making  the  bulk  of  most  fillings.  The 
best  results  arc  obtained  from  it  when  the  mallet  is  used  for  its  con- 
densation throughout. 

Annealing  Gold. 

After  the  manufacturer  has  reduced  the  gold  to  the  desired  thinness 
by  beating,  his  last  act  before  booking  it  is  to  heat  it ;  this  is  termed 
annealing.  The  object  of  this  is  to  remove  any  harshness  which  has 
been  given  to  it  by  the  process  of  beating.  All  metals  become  more  or 
less  stiff  or  rigid  by  hammering,  but  become  soft  again  by  the  applica- 
tion of  considerable  heat.  Gold  foil  which  has  been  recently  made  and 
excluded  from  the  atmosphere  or  certain  gases,  as  previously  men- 
tioned, may  present  sufficient  cohesive  properties  to  weld  satisfactorily, 
but  this  property  is  soon  lost,  and  reheating  becomes  necessary  if  it  is 
desirable  to  get  union  of  the  various  layers. 

Most  operators  make  use  of  an  alcohol  flame  for  annealing  gold ; 
others  a  small  Bunsen  gas  burner.  Some  hold  the  piece  of  gold  to  be 
annealed  in  the  direct  flame  or  a  little  above  it ;  others  place  the  gold 
upon  a  tray  of  Russia  iron,  mica,  or  platinum  and  hold  this  in  the  flame 
of  the  lamp  or  gas  jet.  This  latter  method  is  safest,  since  there  are  apt 
to  be  impurities  in  the  flame  dependent  upon  a  charred  wick,  a  particle 
of  ph(jsphorus  dropping  into  the  wick  from  the  burning  match,  or,  in 
the  case  of  the  gas  jet,  imperfect  combustion  which  might  give  either 


INTRODUCTION  OF  THE  GOLD. 


275 


carbon  or  sulfur  deposits  upon  the  surface  of  the  gold.     All  or  any 
of  these  accidents  would  impair  the  working  qualities  of  the  gold. 

The  most  satisfactory  method  of  annealing  gold  is  by  the  use  of  the 
Electric  Annealing  Tray.  Such  a  device  has  been  invented  by  Dr.  L. 
E.  Custer,  and  is  shown  in  Fig.  22(3.     By  this  method  the  gold  can  be 

Fig.  226. 


Custer's  electric  annealing  tray. 

heated  to  anv  desired  decree  and  with  a  uniformitv  not  easilv  attained 
by  the  methods  generally  used.  The  working  qualities  of  foil  whether 
non-coliesive  or  cohesive  are  greatly  enhanced  by  the  application  of 
heat  at  the  time  of  using.  Gold  that  is  absolutely  non-cohesive  is  made 
tougher  by  annealing  and  yet  its  softness  is  not  impaired,  while  cohesive 
gold  may  be  made  either  slightly  or  decidedly  cohesive  according  as 
much  or  little  heat  may  be  applied  to  it.  It  is  the  practice  of  many 
operators  to  use  the  gold  but  slightly  cohesive  when  filling  cavities  sur- 
rounded by  strong  walls,  and  the  gold  known  as  semi-cohesive,  in  the 
form  of  loosely  rolled  cylinders,  is  much  used.  As  the  filling  approaches 
completion  the  cylinders  are  heated  and  additional  cohesive  property 
imparted  to  them.  But  when  the  object  is  the  restoration  of  contour  or 
building  up  of  teeth  Avhich  have  been  broken,  the  gold  should  be  heated 
but  little  short  of  redness  in  order  that  the  greatest  cohesive  property- 
may  be  realized. 

Introduction  of  the   Gold,  and  Manner  of  Adapting  It  to 
THE  Walls  op  the   Cavity. 

It  has  been  shown  in  C'liai)ter  VIII.  that  few  cavities  are  of  proper 
shape  for  retaining  the  filling  when  the  decay  alone  has  been  removed. 
Most  cavities  require  to  be  given  a  retentive  shape  so  that  the  filling' 
shall  not  be  dislodged  during:  its  introduction  or  bv  mastication  or 
otherwise  after  its  completion.  In  former  times,  when  the  operator  was 
restricted  to  one  form  of  gold  and  that  the  non-cohesive  variety,  he  was 
compelled  to  prepare  his  cavities  accordingly  ;  but  at  the  present  time, 
when  the  variety  is  almost  endless,  he  can  shape  his  cavity  with  a  view 


27fi  THE  OPERATION   OF  FILLING   CAVITIES. 

to  conserving  tooth  structure,  and  w  hcii  lie  lias  given  it  a  sliapc  to  please 
liini  he  can  select,  from  the  nuiiiy,  a  special  form  of  gold  that  will  meet 
his  requirements. 

There  are  certain  ])rinciples  involved  in  the  packing  oi"  gold  which 
must  be  borne  in  mind,  and  the  oj)erator  should  study  these  before 
introducing  his  filling.  The  first  of  these  is  force,  and  the  direction  and 
relation  of  that  force  to  the  object  to  be  attained.  If  a  given  cavity  is 
to  be  filled  with  non-cohesive  gold  the  operator  must  take  into  consid- 
eration the  strength  of  the  cavity  walls,  and  must  determine  whether  by 
the  wedging  process  which  he  will  exercise  in  the  effort  to  adapt  the 
gold  to  the  walls  of  the  cavity  he  will  run  the  risk  of  breaking  them. 

Non-cohesive  gold  is  usually  introduced  by  what  is  known  as  hand 
pressure.  Each  layer  of  gold  is  carried  to  the  floor  and  the  walls  of 
the  cavity  by  a  process  of  wedging,  and  the  mechanical  arrangement  of 
each  piece  of  gold  should  be  such  that  no  portion  of  the  gold  can  es- 
cape when  the  filling  is  completed.  It  will  be  shown  later  on,  when 
considering  the  various  types  of  cavities  to  be  filled,  that  in  small  cav- 
ities of  simple  shape  the  gold  prepared  in  the  form  of  tape  is  best 
suited,  whereas  in  compound  cavities  or  those  of  greater  size  the  gold 
may  be  introduced  in  the  form  of  compact  cylinders  or  blocks. 

When  it  is  desirable  to  use  a  combination  of  non-cohesive  and  cohe- 
sive gold,  the  former  is  generally  introduced  first  and  the  cohesive  is  in- 
corporated with  it  by  driving  or  forcing  layers  of  cohesive  into  the  non- 
cohesive.  This  is  best  effected  by  using  single  layers  of  heavy  foil  or 
rolled  gold  of  a  thickness  equal  to  20,  30,  or  40  grains  to  the  leaf.  If 
the  filling  is  to  be  made  of  but  one  kind  of  gold  and  that  the  cohesive 
variety,  both  hand  pressure  and  percussion  by  means  of  the  mallet 
may  advantageously  be  employed.  The  operator  who  has  learned  to 
combine  the  two  forms  of  gold  and  is  not  restricted  to  either  method 
of  packing  is  best  qualified  for  the  requirements  which  are  presented  in 
general  practice.  Perfect  adaptation  to  the  walls  may  be  effected  by 
either  method,  but  greater  celerity  and  the  attainment  of  equal  excel- 
lence may  be  reached  by  combining  the  two. 

Plugging  Instruments. — In  the  selection  of  instruments  for  pack- 
ing gold  the  operator  should  have  a  sufficient  number  to  meet  his  every 
need.  They  should  be  of  such  a  variety  of  patterns  that  every  part  of 
every  cavity,  however  remote,  can  be  reached  with  ease.  It  is  a  mis- 
taken notion  that  a  large  number  of  instruments  (if  well  selected)  is 
confusing.  The  operator  should  study  his  instruments  and  know  their 
uses  as  thoroughly  as  he  knows  the  letters  of  the  alphabet,  and  if  this 
be  done  and  they  be  arranged  in  an  orderly  manner  in  his  case,  the 
confusion  will  be  manifest  in  their  absence,  not  in  the  possession  of 
them. 


INTRODUCTION  OF  THE  GOLD. 


277 


For  packing  non-cohesive  foil  none  are  better  adapted  than  the  set 
shewn  in  Fiu'.  227,  made   from  patterns  furnished  by  Dr.  B.  J.  Bing. 


Fig.  227. 


11 


13 


14  15  16  17 

Dr.  Bing's  set  of  pluggers. 


i  ill  I      "^^^^^  ^^*  shoukl  be  supplemented  by  a  small  and  a  medium 
li  ill  B      p-2g(i  foot-shaped  condenser  (Fig.  228),  for  packing      p^^^  228. 

cylinders,  mats,  or  blocks  against  the  cervical  wall. 

The  handles  of  instruments  used  for  packing 
non-cohesive  foil  should  be  of  such  size  that  they 
can  be  grasped  firmly  in  the  hand.  AVhen  made 
of  wood  they  are  light  in  weight  and  agreeable  to 
touch.  Plugging  instruments  should  have  as  few 
curves  and  angles  as  is  consistent  with  the  ability 
to  reach  all  points  in  the  cavity.  As  these  are 
multiplied,  direct  force  is  sacrificed.  The  point  of 
the  instrument  should  be  as  nearly  as  possible  in  a 
line  with  the  shaft.  Deviations  from  this  rule  are  sometimes  necessary 
in  order  to  reach  all  points  in  the  cavity.  jNIost  plugging  instruments 
have  serrated  points  and  are  used  for  all  forms  of  gold.  As  a  rule  these 
serrations  should  be  shallow,  and  when  cohesive  gold  is  to  be  employed 
they  should  be  only  sufficient  to  prevent  slipping,  as  gold  that  is  quite 
cohesive  packs  as  readily  with  smooth  points  as  with  rough  ones. 


Foot-shaped 
condensers. 


278  THE   OPKIIATION  OF  FILLING   CAVITIES. 

Fig.  230. 

Fig.  231. 
Fig.  229. 


Snow  and  Lewis  auto- 
matic mallet. 


The  Abbott  mallet 


S.  S.  White  electric  mallet  "  No.  2.' 
Founded  on  the  "  Bonwill." 


INTRODUCTION  OF  THE  GOLD.  279 

It  is  not  definitely  known  when  packing  gokl  by  percussion  W'as  first 
suggested,  but  the  idea  is  quite  generally  accorded  to  Dr.  E.  Merrit  of 
Pittsburg,  who  as  early  as  1838  used  the  hand  mallet  for  condensing 
the  surface  of  fillings  which  had  been  introduced  by  hand  pressure. 
The  first  mallets  used  were  of  light  weight  and  were  made  of  w^ood  or 
ivory.  As  the  method  became  more  general,  heavier  mallets  were  em- 
ployed, and  those  made  of  lead,  tin,  various  alloys,  and  steel  found  much 
favor.  Before  the  introduction  of  rubber  dam  for  excluding  moisture 
one  hand  of  the  operator  was  employed  in  holding  the  napkin,  and  it 
became  necessarv  to  have  an  assistant  at  hand  to  do  the  malleting:. 
This  led  ingenious  minds  to  discover  some  means  of  percussion  besides 
the  hand  mallet,  and  several  spring  instruments  known  as  automatic 
pluggers  were  introduced.  The  Snow  and  Lewis,  the  Foote,  and  the 
Salmon  found  greatest  favor,  and  all  of  them  were  good  of  their  kind. 
The  accompanying  cut  (Fig.  229)  shows  the  Snow  and  I^icwis  Automatic 
Mallet  as  made  at  the  present  time.  When  pressure  is  applied  to  the 
point  of  the  instrument  a  spring  is  liberated  wdiich  throws  a  plunger 
forward  with  great  force,  which  is  expended  upon  the  gold  beneath  the 
point.  The  impacting  quality  of  this  blow  is  not  excelled  by  any  of 
the  mechanical  devices  in  use.  It  is  so  constructed  that  a  light  or  a 
heavy  blow  can  be  given  at  will.  The  operator  will  do  well  to  adjust 
the  instrument  for  light  blows  when  using  it  in  close  proximity  to  frail 
or  delicate  walls,  as  there  is  more  or  less  danger  of  fracturing  them. 

Instruments  of  this  class  are  not  well  adapted  to  packing  gold  in 
the  posterior  teeth  of  the  lower  jaw,  as  the  blow  is  delivered  at  a  more 
or  less  acute  angle,  and  unless  care  be  exercised  when  the  operation  is 
nearing  completion  the  plugger  point  will  slip  from  the  surface  of  the 
filling  and  wound  the  soft  tissues. 

Another  instrument  of  this  type  devised  by  Dr.  Frank  Abbott  (see 
Fig.  230)  has  a  socket  at  either  end  of  the  hand-piece,  the  one  giving  a 
pushing  and  the  other  a  pulling  blow.  The  latter  is  serviceable  for 
condensing  gold  upon  distal  surfaces. 

The  ELECTRIC  MALLET  is  One  of  the  most  ingenious  devices  em- 
ployed in  dentistry.  The  first  practical  application  of  electro-magnetic 
force  for  dental  malleting  was  made  by  the  late  Dr.  AV.  G.  A.  Bonwill. 
Its  latest  development  is  shown  in  Fig.  231.  This  instrument  has 
found  great  favor  among  dentists  for  packing  cohesive  gold.  Its  blows 
are  delivered  with  great  rapidity  and  with  such  force  that  great  solidity 
is  attainable.  A  pair  of  electro-magnets  transforms  the  electric  current 
into  electro-magnetic  force,  which  is  transmitted  to  the  hammer.  The 
electric  current  is  furnished  by  a  Buusen  or  Partz  battery,  or  the  con- 
trolled current  from  a  dynamo  or  storage  battery  can  be  used  as  the 
motive  power.     In  the  hands  of  a  skilful  operator  there  could  be  nothing 


280 


THE  OPERATTON  OF  FILLJNfi   CAVITIES. 


better  for  j);if'kini»;  cohesive 
gold.  I'lie  best  results  arc 
obtained  by  its  use  when  the 
gold  is  prepared  in  thin  lani- 
ina;  or  where  a  single  thick- 
ness of  heavy  foil  or  rolled 
gold  is  employed. 

Considerable  experience  is  necessary  to 
enable  the  o])erator  to  use  this  instrument 
with  satisfaction  to  himself  and  his  patient. 
If  the  plugger  point  be  pressed  hard  against 
the  filling,  the  blows,  which  are  delivered  with 
great  rapidity  and  force,  become  painful  and  dis- 
tressing and  there  is  also  danger  of  chipping  the 
cavity  walls.  The  better  plan  is  to  hold  the  point 
slightly  away  from  the  surface  of  the  filling  and 
allow  the  mouKMitum  which  is  given  the  instru- 
ment by  the  falling  armature  to  complete  the 
union  of  the  various  pieces  of  gold. 

The  ENGINE  MALLET  (sec  Fig.  232)  is  intended 
for  use  upon  the  dental  engine.  It  is  made  with 
a  slip  joint  and  can  be  applied  in  place  of  the 
hand-piece  to  nearly  all  of  the  dental  engines  in 
use,  although  it  is  best  adapted  to  one  of  the 
"  cord "  engines  because  of  the  greater  freedom 
of  action.  The  instrument  shown  in  the  illus- 
tration embodies  many  improvements  in  con- 
struction which  have  been  suggested  by  various 
operators  since  the  "  Bonwill  mechanical  mallet," 
on  which  it  is  based,  was  introduced,  and  a  jioint 
of  relative  perfection  has  been  reached  where  are 
combined  great  efficiency  with  compactness  and 
lightness  in  handling.  It  will  be  seen  by  the 
illustration  that  the  essential  feature  of  this  in- 
strument is  a  revolving  wheel  having  inserted  in 
its  periphery  a  hollow  cylindrical  steel  roller. 
This  constitutes  the  hammer.  It  gives  a  "  spring," 
not  a  "dead"  blow,  as  it  is  held  to  its  position  by 
a  stiff  steel  spring.  The  roller  revolves  slightly 
in  its  socket  at  each  contact  with  the  plimger. 
When  the  engine  is  run  at  ordinary  speed  the 
small  wheel  revolv^es  with  great  velocity,  deliver- 
ing upon  the  head  of  the  plunger  as  many  as  fif- 


Fio.  232. 


Engink  Mallet. 


"^' 


® 


INTRODUCTION  OF  THE  GOLD. 


281 


teen  blows  per  second.  The  force  of  the  blow  can  be  modified  at  will 
by  an  extremely  simple  contrivance,  as  follows  :  The  interdigitations 
seen  around  the  upper  end  of  the  sleeve  are  held  together  by  means  of 
a  spring  attached  to  the  sleeve.  Pulling  the  sleeve  away  from  the  head 
against  the  spring,  and  revolving  it  to  the  right  or  left,  raises  or  lowers 
the  head  of  the  plunger.  Upon  releasing  the  sleeve  the  spring  at  once 
throws  it  back  to  engage  with  the  head,  and  the  blow  is  heavier  or 
lighter,  according  to  the  direction  in  which  the  sleeve  has  been  revolved. 
The  impacting  power  of  the  blow  from  this  is  great,  and  in  the 
hands  of  an  experienced  operator  a  large  quantity  of  gold  can  be  con- 

FiG.  233. 


Webb's  set. 


Chapiiell's  set. 

densed  in  a  short  space  of  time.  When  cohesive  gold  foil  is  employed 
smooth  oval  points  may  be  used  M'ith  most  satisfactory  results.  The 
point  should  not  be  pressed  hard  against  the  filling,  but  a  skimming  or 
smoothing  motion  given  to  the  instrument.  The  surface  of  the  filling 
when  thus  packed  has  a  jwlished  or  planished  appearance  as  if  done 
with  a  hand  burnisher.     Such  fillings  are  usually  of  great  density. 

There  are  other  mechanical   mallets  intended  for  use  on  the  engine 
which  have  what  is  known  as  a  "  cam "  movement.      They  are  not, 


282  THE  OPERATION  OF  FILLING   CAVITIES. 

strictly  speakinfj,  mallets,  for  the  instriinu'iit  is  pushcfl  rather  than 
driven  forward  l)y  an  eeeentrie.  Tlie  ]iiiekingham  and  the  Holmes 
mallets  belong  to  this  class.  They  have  not  the  same  steadiness  of 
motion  as  the  ones  previonsly  described,  and  for  this  reason,  among 
others,  have  not  been  in  general  nse. 

In  the  selection  of  jjluyger  points  for  })ower  mallets  the  operator  will 
do  well  to  confine  himself  to  those  having  more  than  one  row  of  serra- 
tions and  those  which  are  smooth-faced.  The  serrations,  if  any,  should 
be  extremely  shallow,  and  the  corners  of  the  instrument  slightly 
rounded.  Those  of  the  foot-shaped  variety  are  admirably  adapted  to 
power  mallets,  and  as  there  is  a  great  variety  of  patterns  and  sizes  he 
will  have  little  difficulty  in  meeting  his  every  wish  in  this  particular. 
A  few  points  selected  from  the  Webb,  the  Varney,  and  the  Chappell 
sets  will  fill  all  requirements.  The  accompanying  cut  (Fig.  233)  shows 
a  ffood  working  set  which  has  been  selected  from  the  three  mentioned. 

Filling — by  Classes. 

(As  arranged  in  Chapter  VIII.) 

I.  Simple  Cavities  on  Exposed  Surfaces. 
Bicuspids  and  Molars. 
Class  A. — The  small  cavities  upon  the  occluscd  surfaces  of  the 
bicuspids  and  molars  are  among  the  simplest  in  form.  They  are  shown 
in  Chapter  VIII.,  Fig.  173.  Cavities  of  this  kind  are  quickly  filled 
by  means  of  non-cohesive  foil  in  the  form  of  tape  as  shown  in  Fig. 
222.  Such  cavities  are  usually  of  regular  shape  and  of  a  form  re- 
quiring little  if  any  additional  shaping  to  make  them  retentive.  A 
length  of  tape  varying  from  an  inch  to  two  inches  should  be  taken 
upon  a  wedge-shaped  plugger  point  and  carried  to  the  bottom  of 
the  cavity,  ^vhere  it  may  be  held  for  an  instant  with  a  point  in  the 
left  hand  ;  the  instrument  in  the  right  hand  makes  a  fold  of  the  gold 
and  carries  it  into  and  against  the  Avails  of  the  cavity  by  a  lateral  mo- 
tion ;  fold  after  fold  is  then  carried  into  the  cavity  and  pressed  firmly 

in  every  direction.     As  it  is  alwavs  best  to  finish  such  fill- 
"Fif    234  '' 

ings   with   cohesive   gold,  a   strip   of  No.   20  cohesive  foil 

should  be  wedged  into  the  mass  already  in  the  cavity,  and 
then   all   subsequent  pieces  malleted,  to  give  the   occlusal 
surface  as  great  hardness  as  possible.     A  completed  filling 
of  this  class  is  shown  in  Fig.  234.     Perfect  adaptation  to 
the  walls  of  the  cavity  is  obtained  by  the  use  of  the  non- 
cohesive   foil,   and    great    solidity   is   only  essential   upon   the   surface. 
Cavities  of  this  character,  though  of  greater  size,  are  found  in  the 
molars,  as  shown  in  Figs.  235-237,  and  may  be  filled  in  the  same  gen- 


SIMPLE  CAVITIES  ON  EXPOSED  SURFACES. 


283 


eral  way.  Mats  of  foil  may  be  substituted  for  tape,  and  where  the  decay 
has  progressed  to  such  an  extent  as  to  involve  a  large  portion  of  the 
occlusal  surface,  making,  as  is  frequently  found,  large  round  and  quite 
deep  cavities,  the  gold  may  be  introduced  in  the  form  of  cylinders. 
In  former  times,  when  the  dentist's  only  means  of  excluding  moisture 


Fio.  235. 


Fig.  236. 


Fig.  237. 


Fig.  238. 


Occlusal  cav- 
ity with  cyl- 
inders. 


Fillings  in  molar  fissure  cavities. 

was  the  napkin,  and  when  his  ability  to  keep  cavities  free  from  saliva 
was  for  a  limited  time  only,  the  use  of  cylinders  was  much  more  com- 
mon than  at  the  present  time  when  the  rubber  dam  is  generally  em- 
ployed. 

Cylinders  for  such  cavities  should  be  hand-made  and  of  No.  4  non- 
cohesive  foil  (Fig.  238).  They  should  be  long  enough  to  extend  above 
the  margins  of  the  cavity  as  shown  in  Fig.  238  and  arranged 
around  its  walls.  The  first  one  is  usually  carried  to  that 
point  in  the  cavity  farthest  away,  and  should  be  pressed  with 
a  foot-shaped  instrument  against  the  wall.  Others  are  then 
})ut  in  place  and  wedged  laterally  until  room  is  made  in  the 
centre  of  the  mass  for  another  cylinder,  this  in  turn  being 
wedged  toward  the  outer  walls,  and  the  operation  continued 
until  no  more  cylinders  can  be  introduced.  The  cylinders 
should  then  be  condensed  with  great  force  upon  their  pro- 
truding ends,  and  finished  with  cohesive  foil  in  the  same 
manner  as  previously  described.  This  mode  of  filling  is  best  suited  to 
deep  cavities  in  which  the  walls  are  nearly  parallel  and  yet  sufficiently 
strong  to  endure  great  lateral  pressure. 

In  a  cavity  of  unequal  depth,  where  the  central  portion  is  quite  deep 
and  the  sulci  radiating  from  it  quite  shallow  (see  Fig.  239),  it  is  well  to 
use  semi-cohesive  foil  in  the  central  portion  and  cohesive 
foil  in  the  radiating  sulci.     Such  fillings  require  to  be  well 
anchored  at  the  extremities  of  the  fissures  lest  they  be  dis- 
lodged by  sticky  candy,  which  often  adheres  with  great 
tenacity  to  the  surface  of  the  gold.     The  operator  will  do 
well  in  filling  such  cavities  to  confine  himself  to  gold  that 
is  quite  cohesive,  except  in  the  central   portion  as  above 
indicated. 
Class  B. — Cavities  situated  uj^on  the  buccal  surfaces  of  the  bicus- 
pids and  molars  are  rather  more  difficult  to  fill  because  of  the  difficulty 
in  getting  the  rubber  dam  beyond  the  cervical  border  of  the  cavity. 


Fig.  239. 


Filled  stellate 
cavity  in 
lower  first 
molar. 


284  THE  OPERATION  OF  FILLING   CAVITIES. 

When  this  has  been  done  and  perfect  dryness  effected  these  cavities  may 
be  classed  as  simple  ones. 

In  small  or  non-elastic  months  it  is  often  difficnlt  to  reach  the  second 
or  tliird  molars,  hence  the  view  of  the  cavity  is  somewhat  impaired. 
In  selectin<>;  the  gold  for  snch   cavities  the  <)})erator  mnst 
Img.  240.        {i\\;,Q  into  consideration  the  depth  of  the  cavity.     If  it  be 
shallow  he  will  do  better  to  start  his  fillinji;  in  a  retaining; 
pit  and  fill  throutrhont  with  cohesive  foil.     If,  on  the  con- 
trary, the  cavity  be  of  considerable  depth,  he  may  fill  the 
Buccal  cavity     bulk  of  the  cavlty  with  mats  or  tape  m^ade  of  non-cohesive 
in  lower  sec-     ^^^j]    ,^j^^   ^^  j^^  approaches  the  snrface  of  the  fillino:,  incor- 

ond  molar.  ...  ,    .  .  .  . 

porate  with  it  cohesive  gold  and  finish  his  operation  with 
the  last-named  variety.  Snch  cavities  are  often  advantageously  filled 
throughout  with  Watts'  crystal  gold.  This  form  of  gold  is  easily  seated 
and  it  has  no  tendency  to  rock  or  move  in  the  cavity.  A  slight  under- 
cut along  the  upper  and  lower  border  of  the  cavity  is  sufficient  to  hold 
the  filling  in  place  (Fig.  240). 

When  these  cavities  assume  larger  proportions,  as  they  frequently  do 
in  the  k)wer  molars,  and  become  confluent  with  cavities  on  the  occlusal 
surface,  they  should  be  filled  after  the  following  method  :  A  mat  or 
block  of  non-cohesive  foil  should  be  placed  at  the  border  nearest  the 
gum  ;  this  may  be  held  for  a  moment  with  an  instrument  in  the  left 
hand.  One  or  two  other  blocks  may  be  laid  against  this,  and,  Mdien 
they  have  been  well  fixed  in  the  undercut,  should  be  malleted  thoroughly 
against  the  cervical  border ;  the  remainder  of  the  cavity  may  then  be 
filled  with  semi-cohesive  or  cohesive  gold.  The  surfacing  of  all  fillings 
should  be  done  with  gold  which  has  been  made  cohesive  by  recent 
annealing. 

Class  C. — Cavities  do  not  often  occur  on  the  lingual  surfaces  of  the 
bicuspids  or  molars  except  in  teeth  of  very  poor  structure  and  in  teeth 
from  which  the  gum  has  receded  to  a  point  below  the  enamel  border. 
Such  cavities  because  of  their  inaccessible  position  are  difficult  to  fill 
with  gold,  and,  as  a  rule,  some  of  the  plastics  are  indicated.  When  the 
fissures  on  the  upper  molars  become  the  seat  of  caries  they  may  be 
filled  with  gold  in  the  same  manner  as  those  in  class  B.  It  is  usually 
necessary  to  pack  the  gold  in  these  cases  almost  entirely  by  hand  pres- 
sure because  of  the  inaccessible  situation  of  the  cavity. 

Incisors  and   Canines. 

Class  D. — Cavities  upon  the  labial  surfaces  of  the  incisors  and  canines 
situated  at  or  near  the  gingival  border  of  the  gum  were  formerly  the 
source  of  much  annoyance  to  the  dentist  when  gold  was  the  material 
selected  for  filling.     The  principal  difficulty  was  occasioned  by  moi.s- 


SIMPLE  CAVITIES  ON  EXPOSED  SURFACES. 


28i 


Fig.  241. 


Woodward  clamp. 


ture,  either  in  the  form  of  blood  or  serum  from  the  wounded  gum  or 
mucus  from  the  follicles  situated  along  the  mucous  surface.  Since  the 
introduction  of  the  rubber  dam  this  difficulty  has  been  greatly  modified. 
But  when  the  cavity  extends  somewhat  above  the  nor- 
mal gum  line  there  is  more  or  less  difficulty  in  keeping 
the  rubber  above  the  gingival  border  of  the  cavity.  This 
is  best  done  by  taking  a  straight  instrument  the  point 
of  which  has  been  made  very  sharp  by  rubbing  it  upon 
an  Arkansas  hone.  The  dam  is  then  raised  well  above 
the  cavity  border  and  the  jioint  })ressed  firmly  into  the 
dentin  and  held  with  the  left  hand  throughout  the  ope- 
ration of  filling  the  cavity.  A  very  neat  and  valuable 
device  in  the  form  of  a  clamp  has  been  introduced  by  Dr.  W.  A.  Wood- 
ward for  this  purpose.     It  is  shown  in  Fig.  241. 

The  dam  should  include  not  only  the  tooth  to  be  filled,  but  several  on 
each  side  of  it.  With  the  left  hand  it  is  stretched  above  the  margin 
of  the  cavity,  w^hile  with  the  right  hand  the  two  little  points  on  the 
bow  of  the  clamp  are  pressed  firmly  into  the  cementum  above  the  cavity. 
The  clamp  is  then  made  secure  by  turning  the  set-screw%  This  clamp 
when  well  seated  rarely  fails,  and  the  operator  feels  that  this  difficult 
operation  has  become  a  simple  one. 

There  are  cases,  however,  where  the  decay  has  followed  the  receding 
gum  or  extended  beneath  it  to  such  an  extent  that  the  clamp  cannot  be 
used.  To  overcome  this  difficulty  the  gum  should  be  slit  and  a 
"  Mack "  screw  inserted  to  the  depth  of  two  or  three  threads  into  the 
dentin.  The  rubber  dam  is  then  draw'n  above  this  and  held  securely 
above  the  cavity.  When  the  operation  is  completed  the  screw  should 
be  cut  olf  with  the  wedge-cutters  and  nicely  smoothed.  When  the  slit 
in  the  gum  has  healed,  the  portion  of  the  screw  remaining  will  be 
concealed. 

Most  cavities  upon  the  labial  surfaces  are  shallow  and  are  best  filled 
with  cohesive  foil  or  Watts'  crystal  gold.  It  is  well  to  fix  the  first  piece 
securely  in  a  small  retaining  pit  and  build  each  piece 
upon  a  sure  foundation.  As  fillings  upon  the  labial 
surfaces  of  teeth  are  usually  conspicuous  (Fig-  242), 
it  is  often  desirable  to  fill  such  cavities  with  plat- 
inous  gold,  because  the  tint  of  the  two  metals  in 
combination  is  more  nearly  the  shade  of  the  tooth. 
Especially  is  this  true  in  teeth  of  yellowish  hue. 
Class  E. — As  cavities  upon  the  lingual  surface  of  the  incisors  are 
usually  confined  to  the  laterals  and  most  frequently  are  the  result  of 
imperfect  development  of  the  enamel  in  relation  to  the  cingulum  (see 
Chapter  I.,  p.  25) ;  they  are  small  in  size  and  easily  filled.     A  tape  of 


Fig.  242. 


Labial  fillings. 


286  THE   OPERATION  OF  FILLING   CAVITIES. 

lion-cohesive  foil,  or  a  small  mat  of  the  same  material,  may  be  inserted 
into  the  cavity  first,  and  the  fillint;'  com|)letecl  with  cohesive  gold  as  in 
other  cavities  surrounded  by  strong;  walls. 

Class  F. — As  caries  rarely  attacks  the  ineisal  edge  of  the  anterior 
teef/i  the  operation  of  filliiij^:  with  gold  is  usually  confined  to  artificially 
made  cavities,  with  the  view  of  arresting  waste  of  tooth  substance 
caused  by  attrition,  or  where  for  any  reason  it  is  deemed  best  to  "  open 
the  bite."  Great  strain  is  often  brought  to  bear  upon  fillings  in  this 
position,  and  too  great  care  cannot  be  exercised  in  the  shaping  of  the 
cavity  and  the  subsequent  packing  of  the  gold. 

Cohesive  gold  is  best  suited  to  cavities  of  this  description,  and  each 
piece  should  be  freshly  annealed,  that  there  may  be  no  doubt  about  the 
perfect  union  of  each  piece.  It  is  well  to  start  the  first 
piece  in  a  small  retaining  or  starting  pit  and  then  fill  all 
of  the  undercut  before  attempting  to  build  the  gold  above 
the  walls.  As  fillings  in  this  ])osition  are  subjected  to 
great  wear,  the  greatest  hardness  of  surface  attainable 
Kdge  restora-     gj^Qi^jij  ]jq  soup-lit    for,  otherwise    there  will   be  battering 

tion.  .  .  . 

of  the  edges  and  possibly  flaking  of  the  gold.  Platinous 
gold  is  well  adapted  for  this  kind  of  fillings.  Narrow  strips  of  No.  20 
or  No.  30,  well  annealed  and  condensed  with  mallet  force,  will  answer 
a  better  purpose  than  lighter  foil  (Fig.  243). 

II.  Simple  Approximal  Cavities. 
Incisors  and   Canines. 

Class  G. — In  selecting  the  kind  of  gold  and  the  form  in  which  it 
should  be  prepared  for  fillings  upon  the  approximal  surfaces  of  the 
incisors  and  canines,  the  operator  must  consider  the  size  of  the  cavity 
to  be  filled  and  the  retaining  hold  which  he  is  able  to  secure  without 
sacrificing  too  much  of  the  tooth  structure. 

If  the  cavity  be  a  small  one,  situated  midway  between  the  labial  and 
palatal  walls,  and  the  surrounding  borders  be  strong,  a  rapid  and  easy 
way  of  filling  such  cavities  is  to  prepare  the  non-cohesive  foil  in  the 
form  of  narrow  tape.  A  leaf  of  foil  cut  into  four  pieces  and  folded 
with  a  spatula  upon  a  napkin  to  the  width  of  one-sixteenth  of  an  inch, 
and  then  cut  into  lengths  of  three-quarters  or  one  inch,  is  a  good  way 
of  preparing  it. 

An  excavator  of  an  angle  of  forty-five  degrees,  with  the  extreme 
point  broken  off,  makes  a  very  good  instrument  for  packing  such 
fillings.  Space  should  previously  be  obtained,  either  by  the  sIom'  pro- 
cess of  wedging  with  rubber  or  linen  tape  or  by  means  of  the  Perry 
separator. 


COMPOUND  CAVITIES.  287 

When  the  cavity  is  two-thirds  filled  it  is  well  to  use  a  few  pieces  of 
No.  20  cohesive  foil,  so  that  a  dense  surface  may  be  given  to  the  filling. 

Such  cavities  may  be  classed  among  the  simple  ones,  and    Fig.  244. 
present  no  difficulties  except  their  inaccessibility  (Fig.  244). 

The  operator  should  ever  strive  to  conceal  as  much  as  pos- 
sible the  gold  in  the  anterior  part  of  the  mouth,  and  when  it 
is  possible  he  should  preserve  the  labial  wall  intact.  This 
can  often  be  done  by  cutting  away  a  portion  of  the  palatal 
wall  and  by  packing  the  filling  almost  entirely  from  the  under 
side  of  the  tooth.  Where  a  large  portion  of  the  approximal  surface  is 
involved,  the  retaining  hold  for  the  filling  must  be  had  at  the  cervical 
border  and  at  the  cutting  edge.  The  first  pieces  of  gold  should  be  an- 
chored in  a  groove  or  retaining  pit  near  the  cervix  and  the  cervical 
border  made  secure  before  any  other  portion  of  the  cavitv  is  filled. 
The  beginner  will  ordinarily  do  better  to  start  such  fillings  with  cohesive 
foil  or  AVatts'  crystal  gold.  If  the  latter,  he  may  then  complete  his 
filling  Avitli  cohesive  foil.  Non-cohesive  gold  is  rarely  indicated  in  cav- 
ities of  this  description. 

The  electro-magnetic  mallet  or  the  Bonwill  mechanical  mallet  is  well 
adapted  for  packing  such  fillings. 

Bicuspids  and  Molars. 

Class  H. — Cavities  of  medium  size  situated  upon  the  mesial  or  dis- 
tal surfaces  of  the  bicuspids  and  molars  and  not  involving  the  occlusal 
Fig  245  surface  may  be  filled  after  the  same  manner  as  small  cav- 
ities in  the  incisors  or  canines.  Operators  who  are  not  in 
the  habit  of  using  non-cohesive  foil  prefer  starting  such  fill- 
ings in  a  small  undercut  or  retaining  pit  and  filling  through- 
,    out  with  cohesive  gold  prepared   either  in  narrow  ribbons 

Approximal  ® ,  -^       ^    _ 

bicuspid        or  looscly  rolled  cylinders  (Fig.  245). 

^"^'  Such  fillings,  because  of  their  position,  must  be  packed 

largely  by  hand  pressure,   although  the   mallet   may  be   used  as  the 
filling  approaches  completion. 

III.  Compound  Cavities. 
Incisors  and  Canines. 

Classes  I  and  J. — JTesio-labial  and  disto-labial  cay  [ties  in  the  incisors 
and  canines  are  usually  best  filled  throughout  with  cohesive  gold.  Each 
cavity  independent  of  the  others  should  have  retentive  shape,  so  that  in 
the  event  of  one  filling  being  displaced  the  other  will  remain  intact. 

As  a  rule  it  is  better  to  fill  the  cavity  on  the  labial  surface  first, 
because  the  first  pieces  of  gold  are  more  easily  anchored  in  an  accessible 


288 


THE  OPE  RATION   OF  FILLING   CAVITIES. 


Fio.  246. 


Fig.  247. 


cavity,  and  because  also  of  the  danger  of  displacing  the  gold  in  the 
approxiinal  cavity  when  filling  the  channel  connecting  the  two  fillings. 
Every  possible  (uire  should  be  exercised  in  ])ncking  the  gold 
in  cavities  of  this  description.  1'he  gold  should  be  made 
thoroughly  cohesive  by  recent  annealing,  and  be  used  in  pieces 
sutficiently  small  to  prevent  cjlogging.  Such  operations  are 
more  or  less  exposed  to  view,  and  the  greatest  degree  of 
artistic  skill  should  be  bestowed  upon  them  to  render  tlunu 
as  pleasing  as  possible  to  the  eye.  The  original  outline  of 
the  tooth  should  be  restored  with  the  gold,  because  it  pre- 
sents a  better  appearance  than  a  space  between  it  and  the  adjoining 
tooth  (Fig.  246). 

Classes  K  and  L. — Cavities  upon  the  mesio-livgual  or  disto-Ungiial 
surfaces  of  the   teeth  are   filled   in   precisely    the   same   way  as  those 
described  under  classes  /  and  /.     If  the  cavity  be  of  con- 
siderable depth,  non-cohesive  gold  may  be  used  as  part  of 
the  filling,  but  in  any  event  the  bulk  of  the  filling  should 
be  made  of  cohesive  foil  (Fig.  247). 

Classes  31  and  N. — Mesio-incisal ;  Disto-'mcisaL — Cav- 
ities situated  upon  the  approximal  surfaces  of  the  incisors 
and  becoming  confluent  with  one  on  the  incisal  edge  require 
great  care  in  the  matter  of  packing  gold.  It  is  often  an 
advantage  to  have  the  cavity  on  the  approximal  surface  unite  with 
a  natural  or  an  artificially  made  one  upon  the  incisal  edge,  because 
much  better  anchorage  can  be  obtained  in  such  cavities.  Cohesive 
gold  prepared  in  the  form  of  ribbon  or  in  pellets  or  cohesive  cylin- 
ders, if  loosely  rolled,  may  be  used.  The  better  method  is  to  fill 
the  undercut  at  the  cervical  border  of  the  cavity  first,  and  then  bring 
the  gold  toward  the  incisal  edge  as  squarely  as  possible,  keeping  the 
mass  on  a  line  with  the  labial  and  palatal  \valls.  The 
operator  feels  a  sense  of  security  when  he  is  able  to  an- 
chor such  fillings  in  an  undercut  or  retaining  pit  on  the 
incisal  edge.  In  teeth  with  broad  incisal  edges  there  is 
ample  opportunity  to  make  a  strong  retaining  hold,  but 
where  the  edge  is  narrow  a  lateral  cut  into  the  palatal 
wall  one-third  back  from  the  incisal  edge  affords  a  strong 
and  secure  hold  for  that  ])ortion  of  the  filling.  Operations  of  this  class 
require  great  thoroughness  in  the  packing  of  the  gold.  It  should  be 
very  cohesive  and  when  possible  condensed  with  some  form  of  mallet 
(Fig.  248). 

Class  0. — lleslo-disto-incisal. — Where  both  approximal  surfaces 
and  the  incisal  edge  are  united  in  one  cavity,  the  better  plan  is  to  begin 
the  filling  at  the  undercut  near  the  cervical  border  of  the  distal  cavity, 


Fig.  248. 


Mesio-ineisal 
filling. 


COMPOUND   CAVITIES.  289 

and  build  the  gold  squarely  down  as  in  classes  M  and  N  until  the  in- 
cisal  edge  is  reached,  thence  across  the  incisal  edge,  then  fill  the  mesial 
cavity  after  the  same  manner,  uniting  the  three  fillings  at  the  mesio- 
incisal  corner.     It  is  better  to  insert  such  fillings  with  an 
electric  or  a  mechanical  mallet,  as  there  is  always  dan- 
ger, when  packing  across  the  incisal  edge  by  hand  pres- 
sure, of  pushing  one  or  the  other  of  the  fillings  out  of 
the  approximal  surfaces. 

If  no  accident  occurs  in  the  packiiio-  of  the  irold  a     Mcsio-distn-inoisai 
hlhng  thus  made  is  very  secure,  tor  its  t<n'm  is  like  a 
staple  and  each  portion  helps  to  bind  the  others  securely  in  the  triple 
cavity.     Non-cohesive  gold  should  form  no  part  of  such  fillings  (Fig. 
249)." 

Bicuspids  and   Mo/ars. 

Ci^ASS  P. — Jlcsio-occlusal. — The  filling  of  this  class  of  cavities  oifers 
no  serious  difficulties  provided  sufficient  space  has  previously  been  ob- 
tained. As  it  is  desirable  to  restore  with  gold  the  original  outline  of 
the  tooth,  sufficient  space  to  do  this  in  is  a  necessity,  and  the  operator 
will  soon  learn  that  he  can  only  accomplish  good  results  in  proportion 
as  he  recognizes  the  inn)ortance  of  this  preliminary. 

The  cervical  border  is  the  vulnerable  point  for  recurrence  of  decay, 
and  imperfection  here  in  the  matter  of  packing  the  gold  means  speedy 
failure  of  the  filling,  hence  the  importance  of  a  perfect  joint  between 
gold  and  tooth.  This  may  be  obtained  by  either  non-cohesive  or  cohe- 
sive gold  if  due  care  be  exercised  in  its  use.  Where  the  cavity  has  not 
great  depth  and  the  retaining  grooves  are  also  shallow^,  no  better  method 
of  laying  the  cervical  foundation  can  be  adopted  than  by  the  use  of 
Watts'  crystal  gold  or  the  "Velvet"  cylinders,  which  possess  great  soft- 
ness and  some  slight  cohesive  properties.  If  the  operator  has  had 
some  experience  in  working  non-cohesive  foil  he  will  do  well  to  use  a 
mat  of  non-cohesive  foil  at  this  point,  allowing  the  mat  to  extend  some- 
what beyond  the  cervical  border  of  the  cavity.  This  may  be  followed 
by  another  mat  or  two,  after  which  they  should  be  malleted  to  place,  a 
foot-shaped  plugger  point  being  used.  The  upper  third  or  even  one- 
half  of  the  cavity  may  be  filled  after  this  method.  He  should  then 
begin  the  use  of  cohesive  gold.  The  two  kinds  can  be  incorporated  as 
previously  described  and  the  filling  completed  with  gold  which  has  been 
freshly  annealed. 

It  is  always  better  to  insert  too  much  rather  than  too  little  gold,  as 
the  operator  can  shape  the  contour  according  to  his  fancy  or  to  the 
necessities  of  the  case. 

The  occlusal  portion  of  the  filling  should  be  thoroughly  condensed, 

19 


290 


thp:  operation  of  filling  cavttiks. 


Fig.  250. 


as  iiuicli  dopcml.s  upon  this  for  holding  the  filling  in  place.  Great  hard- 
ness is  also  essential  to  ])revent  l)att('rina-  in  the 
act  of  mastication  (Fig.  250). 

Class  Q. —  Disfo-occ/u.^a/  va\]Uc^  may  he  lillcd 
in  ])recisely  the  same  mainier  as  those  situated 
u))(>n  the  mesio-occlusal  surfiice.  The  dilHculties 
are  slightly  greater  because  these  cavities  are  not 
so  accessible.  (  avities  ol'  this  description  can  be 
greatly  simpliiied  by  the  use  of  the  matrix.  This  little  device  converts 
compound  cavities  into  simple  ones,  and  when  used  with  care  and  judg- 
ment fiicilitates  the  o])eration  of  filling  to  a  wonderful  degree.  It  will 
be  observed  in  the  Jack  matrices  (as  shown  in  Fig.  251)  that  jiro vision 

Fig.  2.")1. 


Approximo-occlnsnl 

cavities. 


The  matrices  of  Dr.  Louis  Jack. 


has  been  made  for  contouring  the  filling.  If  this  style  be  employed  the 
operator  must  study  the  outline  which  he  desires  his  filling  to  assume 
and  select  his  matrix  accordingly.  He  must  have  previously  obtained 
ample  space  between  the  teeth  for  the  placement  of  the  matrix. 

When  put  in  place  the  matrix  should  be  thoroughly  fixed  against  the 
tooth  to  be  filled,  with  wedges  of  orange  wood  previously  dipped  in 

Fig  252. 


Kiy     vi>'     v?.' 
Loop  matrices. 


'^iidJ    ^     W     W 


moderately  thick  sandarac  varnish.  This  will  keep  the  wedges  from 
slipping.  A  very  good  way  of  fixing  the  matrix  is  to  pack  between  it 
and  the  adjoining  tooth  some  quick-setting  oxyphosphate  of  zinc.  If 
the  part  be  thoroughly  dry  the  cement  will  become  adherent  to  the 
matrix  and  the  adjoining  tooth  and  the  matrix  will  thus  be  made  secure. 


COMPOUND  CAVITIES. 


291 


"Whenever  the  matrix  is  to  be  employed  it  must  be  understood  that  an 
important  feature  is  absolute  fixation  of  the  device,  otherwise  the  ope- 
rator will  suffer  continual  annoyance  throughout  the  operation. 

Where  there  is  sufficient  space  between   the  adjoining  teeth   for  a 
band  matrix  the  operator  \vill  find  great  satisfaction  in  their  use  (they 

Fig.  253. 


Brophy's  banil  matrices. 


are  shown  in  Figs.  253,  254),  but  as  most  teeth  are  smaller  at  the  neck 
than  at  the  occlusal  surface,  there  is  often  difficulty  in  adjusting  the 


Fig.  254. 


(^ 


1^ 


III 
i       ' 


^ 


Guilford's  band  matrices  and  clamps. 

matrix  to  that  portion  of  the  tooth  :  a  wedge  used  as  previously  described 
will  often  overcome  this  difficulty. 

A  modification  of  the  band  matrix  has  been  devised  by  Dr.  Guilford, 
and  is  shown  in  Figs.  254,  255.  It  will  be  seen  that  space  upon  both 
sides  of  the  tooth  to  be  filled  is  unnecessary,  as  the  little  clamp  binds  the 
matrix  to  the  tooth.  Another  style  of  matrix,  and  one  admirably 
adapted  to  many  cavities  in  the  bicus]iids  and  molars,  has  been  intro- 
duced l)v  Dr.  AV.  A.  "Woodward,  and  is  shown  in  Fig.  256.  It  will  be 
seen   that   this   matrix   has   two   screws  which  are   driven  against  the 


292 


THE   OPERATIOX  OF  FTLLTNG   CAVITIES. 


atljoiiiing  tooth  and  koop  the  matrix  firmly  in  place  and  at  the  same 
time  act  as  a  separator.  If  the  operator  feels  that  he  has  insufficient 
space,  as  his  filling  progresses  he  can  occasionally  tighten  the  screws 
and  gradually  gain  space  between  the  teeth,  which  is  of  value  ^\•hen  he 
is  ready  to  dress  down  and  polish  his  tilling.  Several  sizes  of  these 
should  be  at  hand  to  meet  the  exigencies  of  individual  cases. 

It  has  been  said  that  the  matrix  converts  a  comjjouud  <'avitv  into  a 
simple  one.  This  is  accomplished  by  making  ol"  metal  a  temporary 
fourth  wall  to  the  cavity.     It  must  be  borne  in  mind,  however,  that 

Fir;.  255. 


Examples  showing  uses  of  matrices. 

the  use  of  the  matrix  does  not  lessen  the  care  which  should  at  all  times 
be  exercised  in  the  packing  of  the  filling.  Direct  pressure  against  the 
disto-buccal  and  disto-ling-ual  borders  of  the  cavitv  cannot  be  as  well 
obtained  when  the  matrix  is  used  as  when  it  is  not,  hence  the  importance 
of  having  the  matrix  so  adjusted  that  these  walls  may  be  accessible. 

Cavities  of  this  variety  seldom  require  retaining  pits.  The  cavity  is 
supposed  to  be  of  a  retentive  form.  If  the  matrix  has  been  made  to 
fit  the  cervical  border  of  the  cavity  and  is  thoroughly  wedged  against 
it,  the  filling  may  be  started  with  mats  of  non-cohesive  foil  or  Avith  loosely 

Fig.  256. 


Woodward's  screw  matrices. 


rolled  cylinders.  Two,  three,  or  even  more  may  be  pressed  thoroughly 
against  the  cervical  wall  and  condensed  with  a  hand  mallet  or  with  the 
automatic  mallet.  Similar  pieces  are  then  inserted  and  malleted  to  place 
until  the  upper  third  of  the  cavity  has  been  filled.  Cohesive  gold  may 
then  be  substituted  for  the  non-cohesive  and  each  piece  packed  with 
hand  pressure  or  mallet  force  as  preferred.  The  instruments  shown  in 
Fig.  257  are  well  adapted  to  fillings  of  this  description. 

As  there  is  sometimes  difficulty  in  adjusting  the  matrix  to  the  cer- 
vical border  of  the  cavitv,  it  is  well  at  times  to  insert  a  cylinder  or  two 


COMPO  UND   CA  VITIES. 


293 


before  piittine^  tlie  matrix  in  position,  letting  the  ends  of  the  cylinder 
extend  beyond  the  walls  and  into  the  space  between  the  teeth.  The 
matrix  is  then  put  in  place  and  rests  upon  the  protruding  ends  of  the 
cylinders.  These  are  condensed  against  the  cervical  border  and  the 
o})eration  is  completed  as  previously  described.  The  introduction  of  the 
cylinders  as  stated,  previous  to  the  adjustment  of  the  matrix,  contributes 
largely  to  the  successful  formation  of  a  tight  joint  of  the  gold  and  the 
cervical  bonier.  Or  the  same  object  may  be  accomplished  with  perhaps 
greater  certainty  by  adjusting  a  band  matrix  and  screwing  it  tightly 
into  close  contact  Avith  the  tooth  surfaces.  When  this  is  done  there  will 
usually  be  found  a  slight  space  betAveen  the  matrix  and  the  tooth  at  the 
cervical  border,  caused  l)y  the  band  standing  away  from  the  tooth  at 
that  margin.  In  filling  this  cavity  the  first  pieces  of  gold,  preferably 
loosely  rolled  cylinders  or  mats,  are  grasped  singly  by  the  foil  tweezers 
near  the  end  and  passed  endwise  into  the  space  between  the  matrix  and 


Matrix  pluggers. 

the  cervical  margin  of  the  cavity.  The  end  projecting  into  the  cavity 
is  then  bent  inward  and  over  the  cervical  margin  and  pressed  firmly 
down  upon  the  cervical  wall.  Other  pieces  of  gold  are  then  similarly 
introduced  and  condensed.  This  forms  the  foundation  of  the  filling, 
after  which  the  operation  is  completed  with  cohesive  foil  as  before  de- 
scribed. Tile  advantages  of  this  nu'thod  are  that  the  first  ])ieces  of 
gold  by  being  wedged  between  the  nuitrix  and  the  neck  of  the  tooth 
are  immovably  held,  thus  rendering  the  usual  starting  anchorages  un- 
necessary. This  method  also  giyes  positive  assurance  that  the  cervical 
border  is  j)erfectly  filled.  The  same  perfection  of  joint  at  the  lateral 
maro'ins  of  the  fillinii;  may  be  attained  where  a  band  matrix  of  the  Guil- 
ford  type  is  employed  by  slightly  loosening  the  set-screw  of  the  matrix 
clamp  as  the  operation  proceeds,  so  that  the  band  may  be  moved  from 
contact  with  the  lateral  margins  of  the  cavity  and  the  gold  carried  over 
them  as  was  done  at  the  cervical  margin.  Moreover,  when  excessive 
contour  is  desired  it  is  easily  accoinplislied  In-  a  gradual  loosening  of 


294 


THE   OPERATION  OF  FILLING   CA  V/TIh'S. 


the  clamp  screw  as  the  operation  proceeds  and  the  additional  space  is 
needed. 

The  matrix  is  best  snited  to  disto-occlusal  cavities.  It  is  sometimes 
emj)loyed  upon  mesio-occlnsal  cavities,  but  as  a  rule  obstructs  the  lif^ht 
and  adds  little  to  the  convenience  of  the  operatcjr. 

Experience  has  demonstrated  that  the  only  satisfactory  method  of 
filling  cavities  upon  the  approximal  surfaces  of  the  bicuspids  and  molars 
is  to  restore,  by  means  of  fillino;  material,  the  original  outline  of  the 
tootii.  This  is  termed  "  restoration  of  contour."  To  do  this  success- 
fully requires  artistic  sense  and  mechanical  skill  of  a  hitili  order,  and 
an  accurate  knowledge  of  the  topographic^al  anatomy  of  the  teeth.  To 
the  man  who  has  these  the  operation  is  easy,  but  otherwise  persistent 
efi'ort  alone  will  enable  him  to  ac(piire  the  ability,  "^riie  iiiexj)erienced 
operator  will  often  do  better  if  he  confine  himself  in  the  beginning  to 
but  one  kind  of  gold,  and  that  of  the  cohesive  variety.  If  this  be  done 
he  should  start  the  filling  in  a  well-defined  groove  at  the  cervical  border 
of  the  cavity,  and  then  add,  piece  by  piece,  well-annealed  foil  until  the 
filling  is  completoKl.  Such  a  procedure  is  of  necessity  slow,  but  excel- 
lent operations  can  be  made  by  this  method.  The  beautiful  and  lasting 
operations  of  Varney  and  Webb  and  others  Avere  made  in  this  way. 

Class  R. —  OccluHO-buccal  cavities  are  usually  confined  to  the  lower 
molars.  If  they  be  shallow  it  is  better  to  fill  throughout  with  ciohe- 
sive  gold.  If,  on  the  other  hand,  the  cavity  u]ion  the  occlusal  surface 
be  deep,  non-cohesive  gold  may  be  used  in  part  and  then  cohesive  gold 
used  to  fill  the  channel  connecting  the  two  cavities.  Such  fillings  are 
subjected  to  great  wear  and  should  be  solid  (Fig.  2-58). 

Class  ^S'. — Ocduso-Umpial. — These  cavities  are  nearly  always  con- 
fined to  the  fii'd  and  second  upper  molars,  and  as  a  rule  are  best  filled 


Fig.  258. 


Fig.  259. 


Fig.  260. 


Occluso-buccal  lilling.  Occluso-liugual  filling.  Mesio-occluso-dislal  filling. 


with  cohesive  gold.  The  channel  running  into  the  lingual  aspect  of 
the  tooth  is  not  often  deep,  and  non-cohesive  gold  is  contra-indicated 
(Fig.  259). 

Class  T. — Cavities  upon  the  mesial  and  didal  surfaces  of  the 
bicuspids  often  become  confluent  with  those  upon  the  occlusal  sur- 
face, and  it  becomes  necessary  to  fill  them  as  one  cavity.     Such  ope- 


FILLING    WITH  TIN.  295 

rations  are  simplified  by  the  use  of  a  matrix  upon  the  distal  surface. 
A  band  matrix  could  be  employed,  but  it  obstructs  the  light  somewhat 
and  the  operator  will  more  frequently  confine  himself  to  a  matrix  upon 
but  one  side  of  the  tooth.  The  filling  should  be  commenced  at  the 
disto-cervical  border,  and  after  inserting  a  few  mats  or  cylinders  of 
non-cohesive  foil  proceed  as  in  cavities  described  under  class  Q 
(Fig.   250). 

If  these  cavities  be  of  considerable  size  the  buccal  and  linijual  walls 
are  weakened  and  there  is  danger  of  their  being  broken  away  in  the  act 
of  mastication.  It  is  often  well  to  truncate  the  cusps  somewhat  and 
build  the  gold  well  across  the  occlusal  surface,  allowing  the  strain  to 
come  directly  u[)()n  the  gold  instead  of  upon  the  tooth  structure. 

Filling  with  Tin. 

It  is  not  definitely  known  when  tin  was  first  employed  for  filling 
carious  teeth,  but  it  has  been  used  for  at  least  a  century  and  has  found 
great  favor  with  many.  Prior  to  the  improvement  in  the  formulas  of 
dental  amalgams,  tin  was  used  more  generally  than  at  the  present  time. 

Tin  possesses  certain  inherent  characteristics  which  make  it  valuable 
as  a  filling  material.  Among  these  are  great  malleability,  non-conduc- 
tivity, and  it  is  thought  by  many  to  possess  antiseptic  properties.  But 
while  it  has  desirable  qualities  it  has  also  some  undesirable  ones,  such 
as  softness,  and  when  exposed  to  the  secretions  of  the  mouth  it  discolors, 
— which  facts  render  it  unfit  for  surfaces  exposed  to  great  wear  in  the 
act  of  mastication  and  upon  surfaces  exposed  to  view.  The  discolora- 
tion, however,  is  confined  to  the  surface, and  teeth  filled  with  tin  are  not 
discolored  in  consequence  of  its  presence. 

There  are  various  methods  of  preparing  tin  for  dental  pui-poses. 
That  which  has  found  greatest  favor  in  the  past  is  in  the  form  of  foil. 
The  tin  used  should  be  chemically  pure.  An  ingot  of  the  metal  is 
rolled  into  ribbon  and  then  beaten,  after  the  same  manner  as  gold  foil, 
into  sheets  of  the  desired  thickness.  As  a  rule  it  is  not  beaten  as  thin 
as  the  former.     The  foil  best  suited  for  most  fillings  is  No.  10. 

Pure  tin,  like  pure  gold,  is  cohesive,  and  fillings  of  great  solidity 
can  be  made  if  the  operator  will  exercise  care  in  packing  it.  The  best 
results  are  obtained  by  taking  a  third  of  a  leaf  of  No.  10  foil  and  roll- 
ing it  into  a  loose  rope,  then  cutting  it  into  lengths  of  half  an  inch  or 
less  and  packing  each  piece  with  a  view  of  making  each  part  of  the 
filling  solid.  Some  prefer  folding  the  sheet  with  a  spatula  after  the 
same  manner  as  gold  foil,  and  then  cutting  into  narrow  tape.  Equally 
good  results  are  obtainable  by  either  method. 

A  more  rapid  but  less  satisfactory  manner  of  introducing  the  fillings 
is  to  use  the  tin  in  the  form  of  cylinders,  not  relying  so  much  upon  the 


296  THE  OPEIIATION  OF  FlIAJNd    CAVITIES. 

cohesive  properties  of  the  metal.  Tlie  directions  lor  using  gold  in  the 
form  of  cylinders  will  apply  equally   well   ibr  inserting  tin  foil. 

Felt  Tin. — This  form  of  tin  was  introduced  by  Dr.  Slayton  some 
years  ago,  and  at  one  time  found  favor  with  many  operators.  Tin  thus 
prepared  resembles  coarse  felt,  and  comes  in  sheets  of  various  thick- 
nesses, usually  about  that  of  billiard  cloth.  This  is  cut  into  squares 
or  strips  of  various  widths  and  packed  into  the  cavity  after  the  same 
manner  as  tin  foil.  It  appears  to  possess  no  advantages  over  ordinary 
foil  prepared  as  above. 

Shredded  Tin. — This  form  of  tin,  as  its  name  implies,  presents  a 
shi-edded  appearance,  and  it  is  said  to  contain  a  small  percentage  of 
platinum.  It  is  quite  cohesive,  and  works  with  a  degree  of  softness 
that  is  pleasing  to  the  operator.  It  is  claimed  for  it  that  cohesive  gold 
foil  will  adhere  to  it  much  more  readily  than  to  pure  tin  in  the  form  of 
foil.  If  this  claim  be  valid  the  advantages  are  apparent  when  the 
operator  desires  for  any  reason  to  use  the  two  metals  in  combination. 

Shaving's  of  Tin. — The  cohesive  property  of  tin  is  best  illustrated 
when  it  is  used  in  the  form  of  freshly  cut  shavings  from  a  revolving 
ingot  of  the  metal.  Any  operator  can  prepare  his  own  shavings  and 
have  them  fresh  daily  or  hourly,  if  necessary,  after  the  following 
method  :  Take  an  ordinary  corundum  wheel  two  inches  in  diameter 
and  one-half  inch  in  thickness,  such  as  is  used  in  the  laboratory.  Make 
a  mould  of  this  in  sand  or  marble  dust,  then  melt  in  a  crucible  or  ladle 
enough  pure  tin  to  fill  the  mould.  When  it  has  cooled  mount  accurately 
upon  the  mandrel  of  the  laboratory  lathe,  and  from  it,  with  a  sharp  car- 
penter's chisel,  turn  shavings  of  great  tenuity.  When  freshly  cut,  and 
before  oxidation  of  the  surface  has  taken  place  by  exposure  to  the  atmo- 
sphere, it  will  be  found  that  the  tin  coheres  with  the  same  readiness  that 
pure  gold  does.  Broken-down  teeth  can  be  built  up  by  this  method,  or 
by  means  of  it  surfaces  may  be  contoured  as  with  gold. 

The  plugging  instruments  best  adapted  for  tin  tilling  are  those  hav- 
ing shallow  but  well-defined  serrations  and  points  not  too  broad.  As 
the  marginal  surface  is  approached  broader  points  and  condensers 
may  be  used,  and  the  surface  should  be  well  burnished.  The  ope- 
rator must  not  lose  sight  of  the  fact  that  while  tin  possesses  many 
desirable  qualities  and  is  easily  manipulated,  it  lacks  hardness  and  is 
not  adapted  to  surfaces  where  great  attrition  occurs.  Its  chief  value 
is  found  in  its  use  upon  surfaces  concealed  from  view  and  shielded 
from  wear,  and  in  the  temporary  teeth,  where  its  greatest  value  is 
manifest. 

Tin  fillings  should  be  finished  with  the  same  care  as  gold  ones,  and 
the  same  directions  will  apply  in  all  particulars. 


FINISHING   FILLINGS. 


297 


Finishing  Fillings. 
Much  of  the  beauty  and  utility  of  a  fillino;  is  imparted  to  it  in  the 
finishing.     It  is  not  enough  that  it  be  well  made,  it  must  also  be  -well 
finished  if  the  best  results  are  to  be  attained. 

All  fillings  should  contain  rather  more  gold  than  it  is  intended  shall 
remain,  and  this  for  the  purpose  of  dressing  down  to  such  lines  as  will 
be  artistic  and  practical. 

Fillings  that  are  not  well  condensed  cannot  be  given  a  fine  finish. 
Solidity  of  the  surface  is  an  essential  (piality.  After  the  last  piece  of 
gold  has  been  well  condensed  it  is  well  to  give  the  surfiice  a  thorough 
burnishing  for  the  purpose  of  getting  a  compact  surface  as  well  as  to 
insure  perfect  contact  with  the  margins  of  the  cavity. 

The  simple  fillings  upon  the  occlusal  surfiice  of  the  bicuspids  and 
molars  are  best  dressed  down  with  small  finishing  burs,  as  shown  in 

Fig.  261.  These  are  fine  cut  and  leave 
the  gold  with  a  better  surface  than  when 
cavity  burs  are  used  for  this  purpose. 

The  gold  should  be  cut  away  until 
the  margin  of  the  cavity  has  been 
reached  and  until  all  overlapping  of 
gold  has  been  removed.  The  occlusion 
of  the  tooth  of  the  opposite  jaw  should 
be  noted,  and,  if  it  occludes  unduly  with 
the  filling,  enough  should  be  taken  from  the  surface  of  the  gold  to  pre- 
vent it.     When  a  uniform  surface  has  been  given  to  the  gold,  a  suitable 


Fk;.  261. 


Plug  linishiiis  burs 


Fig.  262. 


Wood  polishing  points. 

W'ood  point  as  shown  in  Fig.  262  should  be  mounted  in  an  engine  man- 
drel and  dipped  first  in  water  and  then  in  fine  pumice  powder  and  the 
surface  nicely  smoothed.  A  round-end  burnisher  may  be  used  if  the 
operator  desires  a  polished  surface,  although  it  adds  nothing  to  cither 
the  beauty  or  the  utility  of  the  filling. 

When  fillings  cover  a  larger  portion  of  the  occlusal  surfiice  the  dress- 
ing down  may  be  done  with  corundum  points,  which  if  kept  wet  will 
cut  more  rapidly  than  l)urs  and  cause  less  heating.  These  arc  shown  in 
Fig.  263,  and  are  of  many  patterns  and  admirably  adapted  to  all  parts 


298 


TlIK   OPERATION  OF  FILLINO    CAVITIKS. 


of  the  filling.     Those  made  of  fine  cornnrlnm  and  shellac,  or  corundum 
and  vuhranized  rubber,  are  more  desirable  than  the  coarse  ones,  which 

Fig.  263. 


('uruniluin  ixiints. 

are  liable  to  grind  away  the  cavity  margins  because  of  the  ra})idity  with 

which  they  cut. 

Fig.  264. 

W'^ n™ 


>houl(l  be  dressed  down 


Fig.  265. 


Felt  polishing  wheels. 
Fig.  266. 


llindostau  points. 

Fillings  upon  labial  and  buccal  surfaces  ;■ 
with  fine  corundum  points  or  the  Hindostan 
stones  shown  in  Fig.  264  until  the  outline  of 
the  cavity  has  been  reached.  Any  overlap- 
ping of  the  gold  upon  these  surfaces  gives  a 
ragged  appearance  to  the  filling  and  detracts  p^  v.^^ 
much  from  its  beauty.  Care  should  also  be 
exercised  in  giving  the  filling  the  same  degree 
of  convexity  that  the  tooth  formerly  had ;  in 
other  words,  the  filling  should  accurately  re- 
store the  lost  anatomical  contour  of  the  tooth. 

When  sufficient  gold  has  been  removed  the 
surface  should  be  nicely  smoothed  with  re- 
volving w^ood  points  charged  with  pumice 
powder  and  water,  or  a  paste  made  of  ])umice 
and  crlvcerin,  after  which  the  final  finish  mav 
be  made  with  flour  of  pumice,  chalk,  or  oxid 
of  tin,  used  by  means  of  a  revolving  disk  or 
wheel  of  felt  or  soft  rubber  (Fig.  265).  The 
soft  rubber  polishing  cup  of  Dr.  John  B. 
Wood  is  a  valuable  aid  in  polit^hing  the  con- 
vex surfaces  of  ap])roximal  fillings  or  those 
upon  the  cervical  portion  of  labial  cavities. 
It  is  shown  in  Fig.  266.  As  fillings  upon  the 
labial  surface  are  more  or  less  conspicu(^us  at  best,  it  is  better  not  to 
give  them  a  burnished  surface.  The  dead  or  satin-like  finish  which  is 
left  by  the  flour  of  pumice  is  usually  j^referred. 


Dr.  Wood's  polishing  cup. 


FINISHING  FILLINGS. 


299 


Fillings  upon  approximal  surfaces  are  more  diffieult  to  finish,  and  too 
great  care  cannot  be  bestowed  upon  them.  .:Vn  operator  is  often  judged 
by  the  finish  which  he  gives  his  approximal  fillings,  and  justly  so,  as 
no  class  of  fillings  requires  a  higher  degree  of  skill  in  the  finishing. 

There  is  of  necessity  more  or  less  overlapping  of  the  gold  in  the 
insertion  of  a  filling,  and  the  removal  of  all  excess  is  as  important  as 
any  other  part  of  the  operation.  For  this  purpose  a  great  variety  of 
instruments  is  supplied.     Files  and  gold  trimmers,  as  shown  in  Figs. 

Fig.  267. 


Plug  finishing  files. 

267  and  268,  are  best  adapted.  The  cervical  border  is  one  which 
should  receive  most  careful  attention.  The  gold  should  be  filed  and 
dressed  down  until  the  finest  excavator  or  probe  will  not  catch  when 
drawn  from  the  cervix  toward  the  cutting  edge.     In  addition  to  the 

Fig.  268. 


^^ 


Curved  finishing  files. 

file  and  gold  trimmer,  strips  of  emery  tape  or  sandpaper  should  be  used 
until  all  margins  are  well  defined.  The  operator  should  have  at  hand 
a  great  variety  of  these  strips,  some  of  extreme  thinness  and  of  various 
grits,  of  emery,  of  silex,  and  of  buckhorn. 

When  the  filling  has  assumed  the  desired  shape  and  all  overlapping 
gold  has  been  removed,  the  final   finish  should  be  given  with   linen  or 


aoo 


THE   UPK RATION   OF  FILLING   CAVITIFS. 


cotton  tn|)(»  chariiod  with  })vinnce  of  oxceedinii,'  fineness.     If  there  are 
places  where  tiie  tape  cannot  he  made  to  reach,  a  soft-rubher  wlieel  in 


¥ui.  269. 


Aiiproxiinal  trimmers. 

the  handpiece  of  the  engine  and  charged  with  the  same  powder  may 
be  nscd  (Fig.  270). 

Fillings  in  the  bicuspids  and  molars  because  of  theii*  inaccessible 
position  are  often  most  difficult  to  finish,  and  for  this  reason  should 
receive  unusual  care.  If  a  matrix  has  been  used  at  the  cervical  border, 
and  has  been  made  to  fit  the  tooth  perfectly  at  or  near  the  gum,  it 
will  be  found  that  the  finishing  process  has  been  simplified  in  a  great 
measure,  because  there  is  less  overlapping  of  the  gold  at  this  ])oint. 


Fig.  270. 


^^W^ 


^'Hh 


Soft-rubber  disks. 


The  pointed  files,  right  and  left,  as  shown  in  Fig.  268,  are  admirably 
adapted  to  dressing  away  any  overlapping  of  gold  at  the  cervical  border. 


Fio.  271. 


Sandpaper  dislis. 

With  these  and  the  trimmers  shown  in  Fig.  269  the  general  outline 
of  the  filling  may  be  obtained,  after  which  the  emery  and  corundum 
tape  may  be  used  and  the  filling  polished  after  the  same  mann(>r  as 


REPAIRIXG   FILLINGS.  301 

described  above.  Disks  of  sandpaper  and  emery  cloth  and  finer  ones 
charged  with  cuttlefish  powder  (Fig.  271)  are  exceedingly  useful  in 
shaping  and  polisliing  the  filling.  Fig.  272  shows  two  forms  of  disk 
mandrels   wiiich  may  be  satisfactorily  used  in  carrying  disks. 

Fig.  272. 

|%1M1\1B»    (  j  ifc : 1^=1 __L^-_-3:^l^^ 

Huuv  disk  mandrul. 


Morsrau-Mastield  disk  mandrel. 


Many  approximal  fillings  in  the  bicuspids  and  molars  extend  to  the 
occlusal  surface.  When  this  is  the  case  the  operator  should  pay  special 
heed  to  the  occlusion  of  the  opposing  teeth.  If  left  too  full  tlie  con- 
stant touching  of  an  opposing  cusp  may  batter  the  filling,  or,  if  not 
securely  anchored,  dislodge  it.  Overlap])ing  gold  is  the  rock  of  offence, 
and  is  the  cause  of  many  failures.  A  filling  is  not  well  finished  until 
a  delicate  instrument  can  be  passed  from  enamel  surface  to  filling  with- 
out catching.  When  this  can  be  done,  and  dental  floss  is  not  fraved  at 
the  cervical  margin,  the  inference  is  justified  that  no  gold  has  been  left 
overlapping. 

Repairing   Fillings. 

Fillings  somewhat  defective  are  often  susceptible  of  repair.  The 
defect  may  sometimes  be  apparent  in  the  finishing ;  at  other  times  it 
is  the  result  of  subsequent  caries,  and  at  still  other  times  the  result  of  a 
fracture  of  the  tooth  enamel  along  the  border  of  the  filling'. 

The  nature  of  the  defect  and  the  condition  of  the  remaining  filling 
must  be  taken  into  consideration  before  an  effort  to  repair  is  undertaken. 

When  the  defect  is  due  to  insufficient  gold  at  any  point  in  the  filling 
more  gold  may  be  added.  It  is  well  to  first  cut  out  a  portion  of  the 
filling,  making  a  distinct  cavity  of  retentive  shape.  Cohesive  gold  is 
usually  best  suited  to  the  purpose  ;  crystal  gold  often  serves  well  in 
the  repair  of  such  defects. 

If  the  filling  has  been  thoroughly  condensed  and  the  mass  is  solid 
there  is  little  difficulty  in  adding  more  gold  to  it,  provided  the  surface 
be  clean.  If  it  has  been  wetted  with  saliva,  the  surface  of  the  gold 
must  be  made  not  only  dry  but  clean.  It  is  well  to  wipe  it  with  a 
pellet  of  cotton  or  paper  saturated  with  alcohol  or  ether,  after  which 
the  filling  should  be  scraped  with  a  suitable  instrument.  If  the  fill- 
ing be  of  considerable   size   and  well   anchored,  shallow   retaining  pits 


302  THE   OPERATION  OF  FILLING   CAVITIES. 

mav  be  drilk'd  into  it,  wliich  will  innkc  :iii  additional  hold  for  the 
irold  which  is  to  he  added.  Defects  which  arise  from  subsequent  caries 
arc  perhaps  nioi-c  frc<|ucnt  in  apjiroxinial  surfaces  at  or  near  the  cervical 
margin.  These  borders  are  vulnerable  |)oints  for  the  recurrence  of 
caries,  and  iniperlcct  adaj)tation  is  not  inlre(|uently  the  determining 
cause  of  the  beginning  of  such  decay. 

To  effect  a  successful  repair  in  such  localities  amj)le  space  should  be 
obtained,  especially  so  if  the  repair  is  to  be  made  with  gold. 

If  the  decay  has  not  extended  beneath  the  filling,  and  sufficient 
.space  has  been  obtained,  there  is  no  greater  difficulty  in  making  a  suc- 
cessful repair  than  in  filling  a  simple  cavity  similarly  located.  If  the 
o[)erator  is  skilled  in  the  use  of  non-cohesive  gold,  he  will  do  well  to 
prepare  his  foil  in  the  form  of  narrow  tape,  and  work  it  into  the  cavity 
fold  after  fold,  allowing  the  loops  to  extend  somewhat  above  the  walls 
of  the  cavity.  When  the  cavity  has  been  completely  filled  the  protru- 
ding folds  may  be  well  condensed  and  the  filling  finished  in  the  usual 
wav  ;  or  the  repair  may  be  made  with  cohesive  gold,  the  first  piece 
having  been  made  fast  in  a  groove  or  retaining  pit. 

Such  repairs  are  often  required  in  the  bicuspids  and  molars,  and 
large  fillings  otherwise  good  are  saved  by  a  successful  repair  at  the 
cervix.  The  plastics  are  sometimes  indicated  in  this  class  of  cases, 
provided  they  be  not  so  near  the  anterior  part  of  the  mouth  as  to  be 
ruisightly.  Gutta-percha  often  serves  a  good  purpose  here,  but  in  some 
mouths  undergoes  decomi)Osition  and  is  less  reliable  than  gold.  The 
oxyphosphates  are  contraindicated  because  of  their  liability  to  wash 
away  after  a  few  months.  Amalgams  are  more  frequently  used,  and 
nearly  always  serve  well  when  thus  employed  ;  but  unfortunately  the 
contact  with  gold  insures  discoloration,  and  an  unsightly  filling  is  the 
result.  Whenever  gold  and  amalgam  are  brought  in  contact  in  the 
same  tooth,  if  the  surface  of  each  is  exposed  to  the  fluids  of  the  mouth, 
the  amalgam  is  almost  sure  to  turn  quite  black.  The  discoloration  of 
the  surface  of  the  alloy  does  not  lessen  its  value  as  a  preserver  of  the 
tooth,  but  its  unsightliness  is  often  too  great  to  be  tolerated  ;  nevertheless, 
utility  enters  so  largely  into  the  equation  that  the  operator  feels  justified 
in  using  the  alloy,  because  with  it  he  feels  sure  of  making  a  better  repair. 
After  the  alloy  has  hardened  it  should  be  nicely  dressed  down  and  all 
overlapping  of  the  material  at  the  gum  margin  removed,  when  it  should 
be  smoothed  and  polished  wnth  the  same  care  that  other  fillings  receive. 

Fracture  of  one  or  more  of  the  cavity  walls  is  a  common  accident, 
and  one  which  may  be  repaired  if  the  filling  has  been  securely  anchored 
in  portions  of  the  tooth  not  involved  in  the  fracture.  Such  accidents 
sometimes  befall  bicuspids  and  molars,  especially  the  bicuspids,  where 
fillings  have  been  inserted  in  each  approximal  surface,  the  two  meeting 


REP  A  IRIS  G   FILLINGS.  303 

in  the  fissure  upon  the  occlusal  surface.  The  buccal  wall  is  sometimes 
the  one  broken  away,  sometimes  the  lingual.  In  either  case  the  ability 
to  successfully  repair  depends  upon  the  stability  of  the  approximal 
fillings  and  the  anchorage  which  can  be  obtained  at  the  cervical  wall 
and  in  the  exposed  fillings.  To  restore  with  gold  a  buccal  cusp  or  the 
entire  buccal  surface  of  a  bicuspid  might  necessitate  a  show  of  gold 
Avhich  Avould  be  objectionable  ;  and  a  better  plan  would  be  to  engraft  a 
porcelain  facing  or  an  entire  porcelain  crown  ;  whereas  such  a  restora- 
tion on  the  lingual  surface  would  not  be  open  to  the  same  objections. 
Cohesive  gold  alone  is  indicated  for  repairs  of  this  kind.  Watts'  crystal 
gold  when  used  in  cases  of  this  description  has  been  most  satisfactory. 

If  the  fracture  extends  above  the  margin  of  the  giun  the  operation 
is  much  more  difficult  because  of  the  danger  from  a  flow  of  blood,  and 
the  additional  difficulty  of  getting  the  rubber  dam  above  the  border 
of  the  fractured  surface.  This  mav  be  accomplished  by  filling  for  a 
few  weeks  with  gutta-percha,  when  there  will  be  recession  of  the  gum 
caused  by  the  pressure  of  the  gutta-percha  upon  it.  When  a  similar 
fracture  occurs  in  a  molar,  if  the  fractured  surface  does  not  encroach 
upon  the  pulp,  and  will  admit  of  drilling  retaining  pits  without  danger 
to  the  pulp,  there  is  no  difficulty  in  restoring  the  broken  portion  with 
cohesive  gold.  Mack's  screws  are  sometimes  indicated  in  cases  of  this 
kind,  since  strong  anchorage  can  be  secured  in  this  way  without  much 
loss  of  tooth  substance. 

Fracture  of  the  incisal  edge  of  the  anterior  teeth  is  often  a  serious 
accident,  because  of  the  difficulty  of  repair  and  the  unsightly  display 
of  gold  when  it  has  been  accomplished. 

Large  fillings  situated  upon  the  approximal  surfaces  of  the  incisors 
but  not  extending  to  the  cutting  edge,  yet  near  enough  to  weaken  the 
enamel  overhanging,  are  especially  liable  to  need  repairs.  The  corner 
of  the  tooth  breaks  away,  leaving  the  surface  of  the  gold  exposed,  and 
the  only  hold  the  filling  has  is  at  the  cervical  border  and  the  slight 
undercut  along  the  labial  and  lingual  walls  of  the  cavity.  In  order  to 
secure  retaining  hold  for  additional  gold  the  operator  must  be  careful  not 
to  displace  the  original  filling.  Sometimes  a  retaining  pit  can  be  made 
laterally  into  the  sound  dentin,  or,  by  cutting  a  little  channel  through  to 
the  lingual  surface  and  then  deepening  the  channel  at  its  extremity  with 
a  round  bur,  a  secure  anchorage  may  be  had  for  the  fresh  gold. 

Great  care  should  be  exercised  in  packing  the  gold  lest  by  inadvert- 
ence the  instrument  shouhl  slip  and  push  the  original  filling  from  its 
position.  Fractured  surfaces  should  receive  prompt  attention,  for  if  left 
for  a  period  of  time  disintegration  of  the  dentin  will  set  in  and  the 
caries  may  extend  beneath  the  filling  and  thus  jeopardize  or  ruin  the 
most  thorough  work. 


304  THE   OPERATION   OE  EILLINU   CAVETIES. 

Eroded  Areas. 

Tliere  is  a  class  of  cavities  wiiich  has  not  been  s[)e<'ifi('ally  tn-atcd  in 
the  f'on'ii:;oiiii;-  chapter,  partly  because  the  lesions  nnder  consideration 
cannot,  strictly  speaking,  be  classed  under  the  head  of"  carious  cavities, 
and  they  are  of  such  a  peculiar  formation  that  no  deliuite  rule  can  be 
laid  down  as  to  the  best  mode  of  treatment.  If  tlu;  eroded  area  be 
narrow  and  confined  to  the  cervical  border  of  the  labial  surface,  and 
in  a  mouth  in  which  the  teeth  are  not  conspicuous,  a  filling  of  gold 
may  be  employed;  but  not  infrequently  the  eroded  area  extends  over 
a  consideral)le  portion  of  the  labial  surface,  and  in  such  cases  a  tilling 
of  gold  would  be  so  inharmonious  that  it  should  be  avoided  if  })ossible. 
Hitherto  the  operator  has  had  little  choice  of  filling  materials,  and  has 
often  been  compelled,  against  his  better  judgment,  to  employ  gold  in 
these  cases. 

The  zinc  phosphates  have  been  almost  as  inharmonious  in  (;olor  as 
the  gold,  and  their  durability  has  been  so  variable  that  they  could  not 
be  regarded  as  permanent  in  character.  The  same  may  be  said  of  gutta- 
percha. 

Happily,  the  progress  which  is  being  made  in  jporcelahi  inlay  work 
promises  something  both  artistic  and  durable.  It  is  quite  possible,  with 
the  great  variety  of  shades  of  porcelain  now  being  furnished,  to  match 
the  tint  of  the  natural  tooth,  and  if  care  be  exercised  in  the  selection  of 
shades  and  the  contour  given  to  the  inlay  these  eroded  areas  may  be 
covered  and  the  tooth  made  to  assume  almost  as  natural  an  appearance 
as  before  the  disease  had  attacked  the  surface.  (For  a  detailed  descrip- 
tion of  porcelain   inlays  the  reader  is  referred  to  Chapter  XV.) 


CHAPTER    XIII. 

PL.ASTIC    FILLING    MATERIALS— THEIR  PROPERTIES,   USES, 
AND  MANIPULATION. 

By  Henry  H.  Burchard,  M.  D.,  D.  D.  S. 


The  materials  included  in  the  heading  of  this  chapter  are — (1) 
Amalgam ;  (2)  Gutta-percha  and  its  preparations ;  (3)  The  basic  zinc 
cements. 

History. — The  introduction  of  the  first  member  of  the  group  was 
not  prompted  by  any  specific  merit  that  it  had  been  demonstrated  to 
possess,  but  was  due  solely  to  its  properties  of  easy  introduction,  com- 
paratively perfect  sealing  and  prompt  hardening,  qualities  which  appar- 
ently recommended  its  wide  and  general  use  to  those  not  possessing  the 
requisite  degree  of  skill  for  the  successful  manipulation  of  gold  foil. 

Applied  upon  a  basis  of  glaring  empiricism,  with  an  absence  of 
technical  skill,  the  material  received  the  prompt  and  sustained  con- 
demnation which  its  abuse  had  warranted.  The  steps  and  phases  of 
this  opposition  of  the  trained  and  skilled  against  untrained  and  un- 
skilled operators  may  be  read  in  the  dental  journals  of  from  1846  to 
1878  and  even  after.     It  was  commonly  known  as  the  "amalgam  war." 

The  first  dental  amalgam  was  that  of  Taveau,  called  "  Silver  Paste." 
It  was  made  of  filings  of  coin  silver  (silver  9,  copper  1),  combined 
with  sufficient  mercury  to  make  a  plastic  mass.  It  was  presumably  this 
alloy  which  was  introduced  into  America  by  two  charlatans  named 
Crawcour,  under  the  glittering  title  of  "  Royal  Mineral  Succedaneum." 
The  discovery  of  the  nature  of  the  paste  followed  soon  after  its  intro- 
duction, which  was  clearly  prompted  by  the  motives  above  stated. 
Thereupon  followed  a  persistent  and  virulent  attack  upon  the  material 
and  all  who  used  it.  Upon  less  than  the  merest  shreds  of  evidence 
alleged  cases  of  salivation  and  mercurial  necrosis  were  recorded  as  due 
to  the  use  of  amalgam. 

That  amalgam  was  still  employed  by  the  practitioners  of  France  is 
evidenced  by  the  presentation  in  1849  of  a  formula  for  an  amalgam 
alloy  of  pure  tin  and  cadmium  by  Dr.  Thomas  Evans,  an  American 
dentist  practising  in  Paris.  An  amalgam  made  from  this  alloy  was 
found  to  shrink,  and  also  to  stain  the  dentin  of  teeth  into  which  it  liad 
been  introduced,  owing  to  the  formation  of  cadmium  sulfid.     It  is  note- 

20  305 


306  PLASTIC  FILLING  MATERIALS. 

worthy  that  Dr.  Evans  himself  was  the  first  to  discover  and  make 
public  the  deficiencies  of  his  amalgam. 

In  America  amalgam  remained  under  a  ban  until  Dr.  Elisha  Towns- 
end  of  Philadelphia,  a  practitioner  of  such  great  skill  as  to  be  safe  from 
any  imputation  of  lack  of  manipulative  ability,  introduced  in  1855  an 
alkjy  of  44^  silver,  55|  tin.  The  amalgam  of  this  alloy  received  an 
endorsement  and  application  based  more  upon  the  eminence  of  its 
author  than  upon  the  results  of  actual  clinical  tests,  and  a  reaction 
occurred  which  brought  amalgam  again  under  general  condemnation. 

What  was  known  as  the  "  new-departure  corps  "  had  its  birth  shortly 
after  this  time.  This  was  composed  of  a  limited  number  of  practi- 
tioners and  metallurgists,  who  were  impressed  by  the  fact  that  gold  as  a 
filling  material  was  not  the  panacea  of  dental  caries,  and  that  by  inves- 
tigation alone  could  the  proper  place  of  amalgam  be  found  in  the  dental 
armamentarium.  It  is  due  to  this  group  of  investigators  to  state  that 
the  history  of  the  rational  employment  of  plastics  is  the  history  of  the 
"  new-departure  corps."  It  was  undoubtedly  due  to  it  that  plastics 
have  come  to  be  regarded  as  substances  having  definite  physical  and 
chemical  properties  which  fit  them  for  application  as  restorati\'e  and 
therapeutic  agents  for  the  relief  of  clearly  defined  physical  and  patho- 
logical states.  As  the  properties  of  these  agents  become  better  under- 
stood, their  employment  more  closely  follows  what  is  known  as  rational 
therapeutics. 

The  use  of  any  or  of  all  of  these  several  materials  is  founded  so 
entirely  upon  their  individual  properties  that  a  discussion  of  these 
properties  must  precede  and  govern  that  of  their  methods  of  manipula- 
tion. 

Natuee  and  Properties  of  Amalgam. 

Ad  amalgam  is  a  combination  of  one  or  more  metals  with  mercury  ;  it 
is  therefore  any  alloy  into  which  mercury  enters  as  a  constituent.  The 
word  amalgam  (Fr.  amalgame)  is  derived  from  Gr.  cifia,  together,  yaiieco, 
I  marry  ;  or  from  cLfia  and  ndlay[xa,  from  iiaXdaaco,  I  soften — because 
of  the  softness  and  fusibility  which  mercury  confers  upon  alloys. 

It  is  to  be  understood  that  amalgams  are  classified  as  alloys,  and  may 
be  therefore  members  of  any  of  Matthiessen's  groups  as  follows  :  A  chemi- 
cal compound  in  which  the  affinities  are  exactly  satisfied  ;  one  in  which 
there  is  unstable  chemical  equilibrium  ;  a  sub-chemical  compound,  or 
a  mechanical  mixture — although  this  latter  is  rare,  as  mercury  exhibits 
some  degree  of  affinity  for  all  metals. 

There  are  two  possible  ways  in  which  mercury  brings  about  the 
solution  of  other  metals  :  First,  by  a  chemical  affinity  for  the  metals ; 
second,  by  lowering  the   melting-point  of  the  solid  metal,   forming  an 


Fig.  273. 

t  ^  »  »  • 

-J. 

1 

* 

NATURE  AND  PROPERTIES  OF  AiMALGAM.  307 

alloy  whose  melting-point  is  higher  than  that  of  a  mean  of  its  constitu- 
ents. The  former  is  the  explanation  more  in  accord  with  the  observed 
phenomena  relative  to  the  combination. 

Physical  Properties  of  Amalgams. — As  a  class  amalgams  have  defi- 
nite physical  properties.  First,  that  of  hardening  from  a  previous 
plastic  condition  ;  and  nearly  all  of  them  for  some  time  subsequent  to 
apparent  hardening  undergo  change  of  volume  and  of  form.  The 
change  of  volume  may  be  either  contraction  or  expansion. 

Contraction  and  Expansion. — In  contraction  the  mass  tends  to 
assume  the  form  shown  in  Fig.  273. 
It  has  been  shown  by  Dr.  Black  ^  that 
the  extent  of  this  contraction  is  due  to 
several  factors  : 

1.  To  the  composition  of  the  jj/-/- 
mctri/  alloy.  All  other  things  being 
equal,  an  alloy  of  65  per  cent,  silver, 
35  per  cent,  tin,  represents  about  the 
fixed  point  where  there  is  a  minimum  ^,.  ",  ~  T  ~  ~,  ~  , 

r  Diagram  of  amalgam  shrinkage. 

of  shrinkage.     As  a  class,  alloys  con- 
taining less  than  65  per  cent,  silver  make  amalgams  which  contract ; 
those    containing    more    than    65    per    cent,    silver    make    expanding 
amalgams. 

2.  To  the  amount  of  mercury  used  in  amalgamation.  There  appears  to 
be  a  definite  percentage  of  mercury  which  produces  the  greatest  strength 
of  an  amalgam  mass  ;  moreover,  the  percentage  which  produces  the 
maximum  strength  increases  the  shrinkage  of  the  shrinking  alloys  and 
increases  the  expansion  of  the  expanding  alloys.  Surplus  mercury  in 
the  amalgam  mass  can  reduce  neither  the  expansion  nor  contraction 
of  the  amalgam  mass.  While  an  excess  or  deficiency  of  mercury  in- 
creases the  shrinkage  or  expansion  of  an  amalgam  (according  as  the 
percentage  of  silver  is  65  —  or  65  +),  these  volume  changes  cannot  be 
overcome  by  the  percentage  of  mercury.  An  excess  or  deficiency  of 
mercury  weakens  an  amalgam.  It  would  appear  that  the  conditions 
which  bring  about  the  most  perfect  union  of  the  metals  produce  the 
greatest  changes  of  bulk  in  those  alloys  in  which  changes  of  bulk  occur. 
An  alloy  the  amalgam  of  which  neither  shrinks  nor  expands  cannot  be 
made  to  do  so  by  changes  in  the  amount  of  mercury  employed. 

3.  A  strong  controlling  factor  has  been  found  to  be  the  evenness 
of  distribution  of  mercury  and  alloy  throughout  the  amalgam  mass. 
An  increase  of  the  ratio  of  silver  above  70  per  cent,  is  followed  by  an 
enormous  expansion  of  the  hardening  mass.  It  had  always  been  noted 
that  the  amalgam  made  of  a  coin-silver  alloy  bulged  from  the  walls  of 

^  Dental  Cosmos,  1895,  vol.  xxvii.  p.  637. 


308  PLASTIC  FILLING  MATERIALS. 

a  cinity  inclosing  it.  This  alloy  contains,  as  stated,  90  per  cent,  of  sil- 
ver. The  ap})earance  of  an  expanded  amalgam  is  similar  to  that  of  ice 
at  the  mouth  of  an  iron  tube  in  which  the  water  has  been  frozen. 

Copper  amalgam  is  the  only  alloy  tested  by  Dr.  Black  which  under- 
went no  change  of  form  in  hardening. 

"  Flow  "  ov  Amalgam. — A  property  attributed  to  certain  amalgams, 
that  of  spheroiding,  has  been  shown  by  Dr.  Black  to  be  without  exist- 
ence. The  bulging  of  amalgams  from  the  orifices  of  cavities  was  held 
to  be  due  to  the  tendency  of  the  mass  to  assume  a  spheroidal  form,  hence 
the  term  spheroiding.  Tests  showed  the  appearance  to  be  delusive,  the 
phenomenon  being  due  to  expansion  and  not  to  a  spheroidal  tendency. 
In  addition  to  the  properties  of  contraction  and  expansion  the  same 
investigator  has  discovered  the  property,  hitherto  unsuspected  in  amal- 
gams, that  o^ flow.  The  property  of  flow — i.  e.  change  of  mass  form,  from 
molecular  motion  under  stress — had  been  observed  in  the  majority  of 
metals,  but  as  found  in  amalgams  it  has  a  unique  expression.  Instead 
of  being  limited  to  a  definite  degree,  proportioned  by  the  stress  applied, 
it  has  been  found  that  amalgams  yield  repeatedly  to  the  same  amount  of 
stress  when  applied  at  intervals,  as  in  mastication,  or  yield  continuously 
when  the  stress  is  constant.  The  process  appears  to  be  without  limita- 
tions. It  is  at  zero  in  copper  amalgams  ;  next  less  in  amount  with  alloys 
containing  55-60  per  cent,  of  silver  with  5  per  cent,  copper  and  the 
remainder  tin.  It  will  be  readily  seen  that  this  property  exercises  a 
great  influence  upon  the  integrity  and  adaptation  of  an  amalgam  filling. 

The  notes  quoted  from  Dr.  Black  were  compiled  from  studies  made 
of  amalgams  whose  exact  chemical  composition  had  not  been  actually 
tested  by  the  investigator.  Later  experiments  ^  made  with  alloys  pre- 
pared with  the  utmost  care  and  exactitude  by  the  investigator  himself, 
gave  widely  different  results  (particularly  as  to  the  effect  of  adding  a 
third  or  fourth  metal  to  the  basal  alloy)  in  the  direction  of  both  flow 
and  shrinkage.  The  first  series  of  experiments  which  appeared  to  show 
an  enormous  increase  of  shrinkage  and  flow  together  with  a  lessening  of 
edge  strength,  by  the  addition  of  a  third  or  fourth  metal  (except  copper, 
which  the  latest  experiments  still  show  to  lessen  flow  and  increase 
rigidity)  were  not  confirmed  when  Dr.  Black  experimented  with  alloys 
made  by  himself,  and  an  additional  and  unsuspected  factor  was  taken 
into  consideration,  viz.  the  influence  of  heat  upon  the  alloy. 

It  has  been  noted  by  Dr.  J.  Foster  Flagg^  that  alloys  which  were 
freshly  cut  possessed  working  properties  different  from  the  same  alloys 
when  "  old  cut,"  or  when  aged.  Dr.  Black's  observations  appeared 
to  confirm  this,  and  his  later  experiments  were  directed  toward  deter- 
mining the  cause  underlying  the  change.     Motion,  which  was  said  to 

'  Dental  Cosmos,  December,  1896.  ^  Plastics  and  Plastic  Fillings. 


NATURE  AND  PROPERTIES  OF  AMALGAM. 


309 


bring  about  the  change,  was  found  to  have  no  influence.  After  exhaus- 
tive and  conclusive  experiments  it  was  ascertained  that  the  change  was 
due  to  a  molecular  alteration  of  the  cut  alloy,  through  a  process  of  an- 
nealing or  "  tempering  " — /.  e.  heat  was  the  agent  producing  the  change. 
The  degrees  of  heat  applied  ranged  from  130°  to  212°  F. 

It  was  found  that  the  amount  of  time  during  which  an  alloy  was 
subjected  to  the  action  of  heat  governed  the  extent  of  tempering ;  for 
•example,  alloy  subjected  to  a  temperature  of  130°  for  a  given  period, 
had  the  amount  of  amalgam  expansion  reduced  a  given  amount ;  if 
the  heat  were  maintained  for  a  longer  period  the  expansion  was  corre- 
spondingly decreased.  Each  formula  has  its  zero  point  beyond  which 
tempering  has  no  eifect. 

In  general  terms,  it  was  found  that  alloys  in  amalgams  which 
expanded  in  hardening  had  the  extent  of  expansion  reduced  by  anneal- 
ing ;  those  which  contracted  had  the  contraction  increased. 

Alloys  which  were  without  alteration  of  volume  unannealed,  shrank 
when  annealed. 

The  following  tables  will  show  the  extent  of  change  produced  by 
annealing.  It  will  be  noted  that  the  alloy  of  72.5  silver,  27.5  tin,  ex- 
hibits the  minimum  contraction  after  annealing.  It  will  also  be  observed 
that  less  mercury  is  required  to  effect  amalgamation  in  the  annealed 
alloy.^  Amalgams  made  from  annealed  alloys  have  both  their  flow  and 
crushing  stress  slightly  increased. 


I.  Exhibit  of  Unmodified  Silver-Tin  Alloys: 


^For  a  full  exhibit  of  this  stupendous  work  of  Dr.  Black's,  the  reader  is  referred 
to  his  contributions  in  the  Dental  Cosmos  for  1895  and  1896. 
2  Black,  Dental  Cosmos,  1896,  p.  982. 


310 


PLASTIC  FILLING  MATERIALS. 


II.  Exhibit  of  Modified  Silver-Tin  Alloys.^ 


FORMULiE. 


Modifying 
metal. 


Gold  5. 
Gold  5. 
Platinum  5. 
Platinum  5. 
Copper  5. 
Copper  5. 
Zinc  5. 
Zinc  5. 
Bismuth  5. 
Bismuth  5. 
Cadmium  5. 
Cadmium  5. 
Lead  5. 
Lead  5. 
Aluminum  5, 
Aluminum  1. 
Aluminum  1, 


Silver.     Tin. 


65 

65 

66.75 

66.75 

6L75 

61.75 

61.75 

61.75 

61.75 

61.75 

61.75 

61.75 

61.75 

61.75 

61.75 

61.75 

61.75 

61.75 

61.75 

64.5 

64.5 


35 
35 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33. 2o 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

34.5 

34.5 


How  pre- 
pared. 

Fresh-cut. 

Per  cent, 
ofmercury. 

Shrinkage. 

Expansion. 

52.33 

0 

1 

Annealed. 

33.00 

10 

0 

Fresh-cut. 

51.52 

0 

4 

.\nnealed. 

33.53 

7 

0        i 

Fresh -cut. 

47.56 

0 

1 

Annealed. 

30.35 

7 

0 

Fresh-cut. 

51.87 

0 

9 

Annealed. 

37.33 

7 

0 

Fresh-cut. 

53.65 

0 

23 

Annealed. 

35.60 

5 

0 

Fresh-cut. 

56.65 

0 

68 

Annealed. 

40.65 

0 

9 

Fresh-cut. 

46.26 

0 

0 

Annealed. 

23.67 

6 

0 

Fresh-cut. 

57.57 

0 

100 

Annealed. 

47.25 

0 

5 

Fresh-cut. 

44.17 

0 

1 

Annealed. 

32.76 

10 

0 

Fresh-cut. 

65.00 

0 

445 

Fresh-cut. 

46.98 

0 

166 

Annealed. 

38.26 

0 

48 

[  Crushing 

!     stress. 


3.67 
5.00 
3.35 
5.06 
4.62 
6.07 
9.68 
8.20 
2.38 
3.50 
1.83 
2.07 
4.78 
5.58 
6.40 
3.54 
4.88 
7.18 

12.60 
17.90 


290 
335 
329 
380 
330 
395 
273 
352 
343 
416 
290 
345 
288 
308 
225 
290 
290 
276 

198 
213 


Edge  Strength. — What  i.s  termed  the  edge  .strength  of  an  amal- 
gam is  the  degree  of  resistance  an  edge  or  angle  of  an  amalgam  mass 
oifers  to  force  which  tends  to  fracture  it. 

Amalgams  have  heretofore  been  regarded  as  rigid  crystalline  masses, 
utterly  devoid  of  malleability.  The  discovery  of  the  existence  of  flow 
at  once  modifies  all  previous  conceptions  and  data  regarding  edge 
strength,  for  it  is  evident  that  a  corner  or  angle  might  not  fracture  and 
yet  might  flow  under  the  stress  of  the  impact  of  mastication,  whereupon 
edge  strength  might  be  said  to  be  great,  and  in  reality  be  but  slight. 
In  view  of  the  existence  of  the  property  of  flow,  edge  strength  must  be 
measured  as  rigidity,  the  antithesis  of  flow,  and  a  high  crushing  stress. 

It  has  been  shown  that  contraction  or  expansion,  and  flow,  are  the 
influences  which  would  disturb  the  maintenance  of  size  and  form  of 
an  amalgam  filling  ;  therefore,  a  minimum  of  shrinivage  and  flow  are 
the  primary  considerations  in  a  satisfactory  dental  amalgam. 

Color. — One  of  the  serious  drawbacks  to  the  wide  employment  of 
amalgam  has  been  its  objectionable  color,  both  in  its  original  state  and 
furthermore  when  it  has  suffered  discoloration  through  the  formation  of 
oxids  or  sulfids  upon  its  surface.  The  silvery  white  of  amalgam  in  its 
most  acceptable  condition  is  not  so  harmonious  a  color  as  the  yellow  of 
gold,  which  fact  has  led  first  to  the  restriction  of  the  use  of  amalgams 
to  such  spaces  as  are  not  readily  visible,  where  its  original  and  subse- 
quently its  altered  color  could  not  be  a  strong  objection  ;  and,  next, 
^  Black,  Dental  Cosmos,  1896,  p.  987. 


NATURE  AND  PROPERTIES  OF  AMALGAM. 


311 


has  prompted  a  modification  of  the  gilver-tin  formiiloe  with  the  object 
of  maintaining  their  original  color. 

The  discolorations  are  not  alone  upon  the  external  surfaces  of  fill- 
ings, but  frequently  (and  most  frequently  in  improperly  prepared  and 
filled  cavities)  the  discoloration  affects  the  dentinal  walls  bounding  the 
cavity  (see  Fig.  274). 

Fig.  274. 


staining  of  tooth  structure  with  amalgam  (Bodecker) :  e.  enamel :  D,  d,  dentin ;  B,  border  of  cav- 
ity ;  s,  solidified  dentin  along  the  border  of  the  cavity  ;  k,  reticulum  brought  forth  by  the 
amalgam.  (X  500.) 

As  shown  in  the  illustration  the  discoloration  may  be  deep.  This 
danger  is  increased  by  leakage,  wlien  putrefaction  of  the  protoplasmic 
contents  of  the  dentinal  tubuH  or  decomposing  albuminous  substances 
generate    H.S,  and  metallic  sulfids  are  formed  in  marked  quantities. 


312  PLASTIC  FILLING  MATERIALS. 

This  danger  of  dentinal  discoloration  is  guarded  against  by  interposing 
a  barrier  between  the  cavity  walls  and  the  amalgam  prior  to  the  inser- 
tion of  the  latter.  The  influence  of  individual  metals  upon  color  will 
be  discussed  later. 

Thermal  and  Chemical  Relations. — As  a  conductor  of  thermal  in- 
fluence, amalgam  is  midway  between  gold  and  the  basic  zinc  cements. 

As  to  the  actual  effects  upon  the  vital  tissues  of  dentin,  it  has 
never  been  demonstrated  that  amalgam  exercises  any  specific  influence, 
except  that  cadmium  appears  to  cause,  through  the  cadmium  sulfid 
formed,  a  degenerative  influence  (Flagg),  and  copper  has  antiseptic 
properties  (Miller,  Fletcher). 

Chemically  the  dental  amalgams  are,  to  all  intents  and  purposes, 
insoluble  in  the  fluids  of  the  mouth,  the  common  solvent  found  in  the 
oral  cavity,  lactic  acid,  affecting  them  but  little. 

Classification  of  Amalgams. — Amalgams  are  divided  into  binary, 
ternary,  quaternary,  and  so  on,  according  to  the  number  of  constituent 
metals.  The  only  binary  amalgams  employed  in  dentistry  are  those  of 
copper  and  of  palladium. 

Binary  Amalgams. — Copper  amalgam  is  made  by  adding  freshly 
precipitated  and  washed  metallic  copper  to  an  excess  of  mercury  ;  when 
solution  is  complete  the  surplus  mercury  is  expressed  through  chamois. 
The  plastic  residuum  is  then  packed  into  moulds  to  make  small  tablets 
of  the  usual  form  in  which  it  is  dispensed. 

A  better  method,  which  yields  a  product  of  greater  purity,  is  to  pre- 
cipitate the  copper  directly  into  the  mercury  by  electrolytic  process. 
This  may  be  done  conveniently  by  pouring  a  quantity  of  mercury  into 
a  suitable  glass  vessel — a  small  battery  jar,  for  example — and  suspend- 
ing a  thick  plate  of  copper,  by  means  of  a  wooden  support,  some  dis- 
tance above  the  surface  of  the  mercury.  A  saturated  solution  of 
cupric  sulfate  is  then  poured  into  the  jar  until  the  copper  plate  is  com- 
pletely submerged.  The  cathode  pole  of  a  battery  or  other  source  of 
electrical  current  is  then  connected  with  the  layer  of  mercury,  and  the 
anode  with  the  copper  plate.  All  that  portion  of  the  cathode  electrode 
in  contact  with  the  cupric  sulfate  solution  should  be  insulated  with  gutta- 
percha, and  only  the  point  which  is  in  contact  with  the  mercury  left 
exposed.  The  passage  of  the  current  causes  solution  of  the  copper 
from  the  anode  and  deposits  it  in  the  mercury  continuously  as  long  as 
the  foregoing  conditions  are  maintained.  The  precipitation  should  be 
continued  until  the  mercury  is  saturated,  which  will  be  evidenced  by 
the  appearance  of  the  characteristic  red  color  of  the  excess  of  copper  at 
the  cathode  pole.  When  the  saturation  point  has  been  fully  reached 
the  mass  should  be  washed,  first  in  dilute  hydrochloric  acid  and  then  in 
water,  dried  and  compressed  as  is  usual  with  this  amalgam  when  pre- 


NATURE  AND  PROPERTIES  OF  AMALGA3I.  313 

pared  by  the  ordinary  processes.  This  method  was  suggested  to  the 
writer  by  Dr.  E.  C.  Kirk. 

In  its  tj-pical  form  and  condition,  copper  amalgam,  when  made 
plastic  by  heat,  may  be  packed  into  matrices,  such  as  cavities  in 
teeth,  where  it  sets  quickly,  undergoes  no  change  of  volume  or  form, 
and  is  devoid  of  flow.  Therefore  a  cavity  which  has  been  sealed  by 
it  remains  sealed.  Upon  its  outer  surface  a  coating  of  black  sulfid 
quickly  forms,  which  remains  but  does  not  penetrate  the  tooth  struc- 
ture. The  dentinal  walls  are  commonly  stained  green  through  the 
absorption  of  the  metallic  salts. 

In  improperly  prepared  specimens  there  is  not  a  perfect  chemical 
union  between  the  metallic  mercury  and  the  copper.  The  presence  in  a 
filling  mass  of  oxids  of  either  of  these  metals  establishes  local  electrolytic 
conditions  which  prevent  the  formation  of  the  black  sulfid  coating  and 
bring  about  the  gradual  dissolution  of  the  amalgam  mass.  To  recapitu- 
late :  Copper  amalgam  is  physically  unchangeable  as  a  filling  material ; 
it  brings  about  very  offensive  discoloration  both  of  the  dentin  and  of 
its  own  surface  ;  it  is  antiseptic. 

The  second  binary  amalgam  is  that  of  palladium.  Palladium  is 
precipitated  from  a  solution  of  its  chlorid  by  iron  or  zinc,  washed  in 
nitric  acid,  and  dried.  To  the  precipitated  metal,  mercury  is  added, 
the  combination  being  attended  by  the  evolution  of  much  heat  (/.  e.  is 
an  active  chemical  union).  If  an  excess  of  mercury  has  not  been  used 
the  amalgam  sets  quickly,  does  not  alter  in  form,'  and  becomes  black 
upon  the  surface,'^  but  does  not  discolor  the  dentin.  The  addition  of 
an  excess  of  mercury  retards  the  setting,  and  produces  an  inferior  filling. 

Ternary  Amalgams. — The  base  of  all  ternary  amalgams  is  the 
alloy  of  silver  and  tin.  The  first  of  these  was  the  alloy  of  ToAvnsend, 
44^  per  cent,  silver,  55^  per  cent.  tin.  From  this  point  the  investi- 
gations and  experiments  radiated — it  being  found  after  many  years  of 
clinical  testing  that  those  alloys  containing  more  than  50  per  cent,  of 
silyer  gave  the  best  results. 

The  formula  given  by  Dr.  J.  Foster  Flagg  as  affording  the  most 
stable  alloy  for  amalgam — 60  silver,  35  tin,  and  5  copper — was  found 
by  Dr.  Black  to  be  that  giving  the  highest  degrees  of  resistance  to 
change  of  form,  to  flo^y,  and  to  crushing.  In  view  of  Dr.  Black's 
researches  into  the  effects  of  annealing  alloys  it  is  evident  that  the 
ternary  amalgam  of  the  future  will  have  a  composition  closely  approxi- 
mating 72.5  per  cent,  silver,  27.5  per  cent.  tin. 

The  binary  alloys  of  tin  and  silver  form  the  basis  of  all  of  the 
quaternary  amalgams  used  in  dentistry. 

^  Tomes,  Trans.  Odontoloqkal  Society  of  Great  Britain,  1872. 
"  Bogue,  Dental  Cosmos,  1884. 


314  PLASTIC  FILLING  MATERIALS. 

Quaternary  Amalgams. — The  metal  additional  to  the  basal  alloy 
is  added  for  the  purpose  of  modifying  the  color  or  increasing  the  edge 
strength  of  the  amalgam.  The  addition  of  copper  5  per  cent,  to  an 
alloy  containing  over  60  per  cent,  silver  increases  the  crushing  stress 
and  lessens  both  flow  and  contraction.  The  alloy  is  white  Avhen  fresh, 
but  in  the  presence  of  sulfur  compounds  discolors. 

The  addition  of  gold  (5  per  cent.),  as  clinical  records  testify,  aids  in 
maintaining  the  color  of  the  filling.  It  lessens  shrinkage  slightly  (com- 
pare this  and  following  statements  with  table  No.  II.),  and  appears  to 
have  little  or  no  influence  upon  flow  and  crushing  stress.  The  addition 
of  platinum  causes  dark  fillings  and  notably  increases  the  flow  ;  the 
setting  is  slowed. 

The  addition  of  zinc  increases  rigidity ;  the  amalgams  expand  for 
long  periods  after  apparent  hardening ;  the  crushing  stress  is  moderately 
high — a  direct  contradiction  of  statements  of  several  previous  ob- 
servers.' 

Additions  of  bismuth,  cadmium,  lead  and  aluminum  were  made  to 
the  basal  alloy,  but  all  of  them  exhibited  properties  which  exclude 
them  from  introduction  into  dental  amalgam. 

Dr.  Black  ^  states  that  "  alloys  containing  5  per  cent,  of  aluminum 
have  their  setting  attended  by  the  evolution  of  much  heat ;  an  enormous 
expansion  of  the  mass  occurs ;  the  instruments  used  in  packing  are  oxi- 
dized, and  a  distinct  crackling  of  gas-disengagement  is  heard."  "  The 
formation  of  aluminum  amalgam  is  characterized  by  an  exhibition  of 
the  affinity  of  aluminum  for  oxygen.  Aluminum  oxid  is  doubtless 
formed,  which  increases  the  volume  of  the  amalgam  mass." 

Washing  of  Amalgams. — Alloys  which  have  been  cut  for  some 
time,  and  mercury  the  purity  of  which  is  questionable,  are  found  to  be 
coated  with  oxids  of  the  metals — in  the  case  of  mercury,  with  the  oxids 
of  contaminating  metals.  The  advisability  of  w^ashing  the  amalgam 
mass  in  some  solvent  which  will  remove  the  oxids  is  a  mooted  question. 
It  has  been  stated  that  the  washing  of  an  amalgam  mass  increases  its 
shrinkage  (Flagg).  On  the  other  hand  it  has  been  observed  that 
washed  amalgams  retain  their  color  better.  It  is  difficult  to  see  how 
the  washing  could  affect  the  integrity  of  the  set  mass  unless  oxidizing 
substances  were  left  in  it ;  and  this  is  clearly  contraindicated  by  the 
maintenance  of  color  in  washed  amalgam.  The  writer  prefers  wash- 
ing the  plastic  mass  in  chloroform  prior  to  expressing  the  surplus  of 
mercury. 

^  It  is  to  be  recalled  in  this  connection  that  Dr.  Black's  measurements  are  made  with 
instruments  of  unequalled  accuracy,  those  of  previous  observers  with  comparatively  crude 
instruments. 

^Private  communication. 


USE  OF  AMALGAM.  315 


Use  of  Amalgam. 

It  is  to  be  understood  that  amalgam  is  to  be  employed  onlv  in  those 
conditions  and  situations  which  clearly  indicate  it  as  the  proper  mate- 
rial. As  a  general  rule,  it  is  excluded  from  the  ten  anterior  teeth  of 
each  jaw,  although  this  rule  is  open  to  exceptions.  Its  anterior  limit 
of  application  is  usually  regarded  as  the  distal  surface  of  the  first  bicus- 
pid. Its  more  general  employment  has  been  greatly  reduced  in  many 
places  since  the  introduction  of  what  are  known  as  combination  fillings 
(see  Chapter  XIV.),  and  by  improyement  in  the  forms  and  character  of 
artificial  crowns. 

The  first  class  of  cayities  to  which  amalgam  is  applied  are  those 
which  extend  beneath  the  gum  margin  ;  the  second,  buccal  cayities  ;  the 
third,  compound  cayities ;  the  fourth,  approximal  cayities  ;  the  fifth, 
cavities  upon  the  masticating  faces  of  the  teeth.  These  are  the  classes 
in  wdiich  gold  is  most  difficult  of  introduction  and  of  proper  shaping 
and  finishing,  in  the  order  named.  Amalgam  should  rarely  or  neyer  be 
packed  against  dentinal  or  enamel  walls  without  the  interposition  of  a 
layer  which  will  prevent  either  the  discoloration  of  the  dentin  or  the 
bluish  apjiearance  noted  when  amalgam  underlies  enamel. 

The  shaping  of  cavities  for  the  reception  of  amalgam  fillings  (see 
Chapter  VIII.)  should  be  done  M'ith  such  care  as  will  2:iye  assurance 
of  the  permanent  retention  of  the  filling  and  the  perfect  sterilization  of 
the  dentin  before  and  during  its  introduction. 

The  separation  of  the  teeth,  removal  of  gum  overhanging  cavity 
margins,  and  breaking  down  of  frail  enamel  walls  by  means  of  chisels, 
precede  the  filling. 

The  rubber  dam  is  to  be  adjusted  where  and  when  possible,  with  such 
care  that  an  exclusion  of  the  fluids  of  the  mouth  is  assured  durino-  the 
shaping,  sterilizing,  and  filling  of  the  cavity.  As  Dr.  Black  has  shown,^ 
much  of  the  permanency  of  form  of  an  amalgam  mass  depends  upon 
the  even  distribution  of  the  constituents  ;  it  is  evident  that  every  aid  to 
this  end  should  be  utilized,  an  important  one  being  that  the  mass  should 
be  packed  into  a  cavity  having  but  one  orifice,  that  for  the  introduction 
of  the  filling. 

AVith  the  data  relative  to  dental  amalgams  which  have  been  given, 
it  is  evident  that  a  dental  amalgam  mass  is  by  no  means  simple,  but  is 
a  very  complex  body.  If  sufficient  mercury  has  been  used  to  effect 
solution  of  the  alloy  particles  the  mass  will  consist,  first,  of  a  quantity 
of  a  chemical  amalgam — /.  e.  one  in  which  the  metals  are  united  in 
atomic  ratios — this  being  surrounded   by  one   or  more   other  distinct 

^  Dental  Cosmos,  1895,  vol.  xxxvii.  p.  553. 


316 


PLASTIC  FILLING  MATERIALS. 


amalgams,  each  having  its  own  time  of  setting  and  rate  of  contraction. 
If  only  enough  mercury  has  been  used  to  make  a  creaky  mass  the  sur- 
faces of  eacli  alloy  particle  are  covered  by  an  amalgam  of  indefinite 
composition  which  acts  as  a  cement  binding  the  particles  together.  In 
this  line  the  same  experimenter  has  shown  that  mixing  the  alloy  and 
mercury  in  a  mortar  by  means  of  a  pestle,  wringing  the  surplus  mer- 
curial solvent  from  the  mass  by  means  of  heavy  pliers,  and  packing  the 
filling  with  steel  burnishers  are  all  influences  which  lessen  the  strength 
of  the  completed  filling. 

The  conditions  are  now  a  prepared  and  sterilized  cavity ;  any  miss- 
ing wall  required  to  give  four  sides  has  been  replaced  by  a  properly 
adjusted  matrix  (see  Figs.  255,  256,  Chapter  XII.). 

Fig.  275. 


Dr.  Herbst's  matrix. 


Matrices. — Matrices  may  be  readily  and  quickly  formed  by  cut- 
ting strips  from  a  sheet  of  very  thin  steel  which  has  been  annealed 


Fig.  276. 


Fig.  277. 


Herbsl  pliers. 


and   polished.     By  means  of  contouring   pliers    the    matrix    is  given 
the   correct   contour,    then    wedged    or   tied    into    place.      They   must 


USE  OF  AMALGAM. 


317 


be  so  adjusted  that  they  are  immovably  held  during  the  filling  ope- 
ration. 

A  rapid  method  of  forming  a  matrix  is  that  of  Dr.  Wilhelm  Herbst : 
A  strip  of  German  silver  No.  33,  wide  enough  to  extend  from  the 
cervical  margin  of  a  cavity  to  its  mouth,  and  long  enough  to  more  than 
embrace  the  tooth,  is  passed  around  the  tooth  (see  Fig.  275) ;  the  strip 
is  caught  near  its  extremities  by  a  pair  of  Herbst  pliers  (Figs.  276, 
277)  and  drawn  taut;  the  pliers  pinch  the  metal  into  close  adaptation 
to  the  tooth  walls.  Held  by  the  pliers  the  matrix  is  withdrawn,  the 
line  of  junction  touched  with  zinc  chlorid  solution,  and  soldered  over 
an  alcohol  or  Bunsen  flame  with  soft  solder.  The  matrix  is  replaced 
upon  the  tooth,  the  rubber  dam  applied,  and  the  matrix  pressed 
against  the  cervical  margin  of  the  cavity  by  means  of  a  wooden 
wedge. 

The  matrices  of  Guilford  and  those  of  Brophy  (Figs.  253,  254, 
Chapter  XII.)  are  operated  upon  a  common  principle ;  the  band  which 
most  nearly  fits  the  periphery  of  the  tooth  is  adapted,  then  drawn 
into  close  apposition  with  the  tooth  by  means  of  the  screw  appli- 
ances. 

The  matrix  of  Woodward  is  one  of  the  most  convenient.  Its  mode 
of  application  is  shown  in  Fig,  256,  Chapter  XII. 

The  Miller  matrix  (Fig.  278)  is  useful  and  adapted  for  the  class 
of  cavities  shown  in  Fig.  279,  as  held  in  contact  with  cervical  mar- 

FiG.  278. 


gins  through  the  action  of  the  duplex  spring  leaflets.  Fio.  279. 

When  necessary  a  wooden  wedge  is  forced  between 
the  leaflets. 

(For  other  forms  and  applications  of  matrices  see 
Chapter  XII.) 

Mixing  the  Amalg-am. — It  is  usually  recom-  Miller  matrix  adjusted. 
mended  that  the  proportion  of  mercury  and  alloy  be  determined  by 
weight.  An  amount  of  alloy  is  first  weighed,  then  weighed  additions 
of  mercury  are  added  to  it  sufficient  to  make  a  plastic  mass,  when  the 
two  are  to  be  mixed  together ;  the  relative  amounts  of  mercury  and 
alloy  are  to  be  gauged  and  recorded  for  eacli  formula  of  alloy.  With 
the  "  submarine  "  alloy  of  Flagg — 60  silver,  35  tin,  and  5  copper — the 


318 


PLASTIC  FILLING   MATERIALS. 


ratio  is  equal  parts  by  weight  of  liling.s  and  iiier- 
curv.  When  a  mortar  is  used  for  niakiug  the  amal- 
gam, one  of  glass  and  having  a  glass  pestle  (see 
Figs.  280,  281)  is  to  be  preferred.  Mixing  in  the 
palm  of  the  hand  is  a  dirty  process,  the  hand  and 
fingers  becoming  much  discolored  by  the  metallic 
oxids. 

Fig.  280. 


iMfl.  i!si. 


Glass  mortar. 


Glass  pestle. 


A  rubber  mortar  (Fig.  282)  to  be  received  in  the  palm  of  the  hand 
has  been  devised  by  Dr.  Genese.     In  view  of  deductions  from  Dr. 


Fig.  282. 


Dr.  Genese's  rubber  mortar. 

Black's  experiments  this  latter  method  of  mixing  is  regarded  as  usually 
the  preferable  one. 

The  filings  are  placed  in  the  receptacle,  the  mercury  is  added,  and 
the  mass  is  triturated — if  in  a  mortar,  by  the  pestle,  if  in  the  rubber 
basin,  by  the  forefinger  guarded  by  a  rubber  finger-stall.     When  the 


USE  OF  AMALGAM. 


319 


amalgamation  appears  to  be  complete  the  mass  is  transferred  to  the 
hand  and  kneaded,  then  pressed  into  a  ball.  It  is  next  enclosed  in 
stout  muslin,  or  China  silk  as  recommended  by  Dr.  C.  E.  Kells,  Jr., 
and  the  surplus  mercury  expressed  by  wringing ;  when  no  more  mer- 
cury appears  through  the  muslin,  the  button  is  removed  :  it  should  break 
with  a  clean,  white  fracture  surface. 

Another  method  of  mixing  the  filings  and  mercury  is  that  of  Fletcher. 
Filings  and  mercury  are  placed  in  a  long  glass  tube  which  is  shaken  vio- 
lently until  amalgamation  is  complete. 

The  Packing  Operation. — Several  devices  have  been  invented  for 
the  pui'pose  of  carrying  the  amalgam  to  the  tooth  cavity,  one  of  the 

Fig.  283. 


most  simple  being  sliown  in   Fig,  283,  and  another  in  Fig.  284.     An- 
other excellent  instrument  is  shown  in  Fig.  285,  one  end  having  ser- 


FlG 


rated   points   which   engage  the   soft   amalgam,  the   other   a   plugger 
head. 

Numerous  methods  have  been  advanced  and  advocated  for  the  pack- 
ing operation.  The  one  commonly  followed  is  that  of  burnishing  the 
amalgam.  This  has  been  shown  by  Dr.  Black  to  weaken  the  mass.  A 
small  piece,  rarely  more  than  a  cube  of  i  in.  side,  is  carried  to  the  deep- 
est and  most  inaccessible  recess  of  the  cavity  and  pressed  against  its 
walls  by  tapping,  burnishing,  or  uniform  pressure.  Dr.  Flagg's  method 
is  by  tapping.  Each  successive  piece  of  amalgam  is  tapped  upon  by  the 
packing  instruments  until  it  combines  with  its  predecessor  and  is  per- 
fectly adapted  to  the  cavity  walls.  The  set  of  instruments  shown  in 
Fig.  286  are  those  by  which  this  process  is  accomplished — Nos.  30-34 
being  packing  instruments,  while  the  others  are  shapers. 


320 


PLASTIC  FILLING  MATERIALS. 


A  convenient  and  effective  set  of  instruments  for  accomplishing  the 
packing  are  shown  in  Figs.  287-289. 


Fig.  286. 


30      31       32       33        34       35        36        37  38  39  40 

Dr.  J.  Foster  Flagg's  amalgam  and  zinc  filling  instruments. 

Dr.  W.  G.  A.  Bonwill  has  advised  a  method  which  accomplishes  the 
removal  of  surplus  mercury  and  the  even  distribution  of  the  mass, 


Fig.  287. 


Woodson's  double-end  amalgam  instruments. 


during  the  progress  of  the  filling.  Small  squares  of  folded  bibulous 
paper  are  caught  in  the  jaws  of  pliers  and  laid  upon  the  amalgam, 
when  the  exertion  of  pressure  by  means  of  amalgam  pluggers  or 
pliers  forces  out  the  surplus  solvent  and  it  is  wiped  away  with  the 
paper.  The  .same  end  is  also  accomplished  by  the  use  of  bulbous 
points  of  soft  rubber. 

When  through  either  method  the  cavity  is  more  than  half  full,  the 
remainder  of  the  amalgam  mass  is  wrung  out  to  express  more  mercury, 
and  the  packing  is  resumed  until  the  cavity  is  more  than  full. 

At  the  later  stages  of  the  filling  the  process  of  wafering  is  usually 


USE   OF  AMALGAM. 


321 


followed.  By  means  of  chamois  and  heavy  pliers  (Figs.  290,  291)  the 
amalgam  mass  remaining  is  compressed  into 
a  wafer,  driving  the  surplus  mercury  through 
the  pores  of  the  chamois.  The  amalgam  is 
put  in  a  piece  of  chamois,  and  the  chamois 
sack  A  is  entered  between  the  beaks  n  and 
C  (the  latter  a  roller)  ;  closing  the  handles 
of  the  instrument  progressively  squeezes  out 
the  mercury  till  any  desired  degree  of  dryness 
is  attained.  "When  the  amalgam  is  squeezed 
to  the  requirements  of  the  operator,  the  han- 
dles are  released,  and  the  spring  opens  the  ap- 
pliance. The  action  is  analogous  to  the  finger 
and  thumb  movement  in  common  use,  but  is 
much  more  powerful,  and  therefore  more  cer- 
tain and  more  uniform.  Small  sections  of  the 
wafer  are  laid  ujion  the  half-completed  filling 
and  tapped  into  a  union  with  it.  The  cavity 
is  more  than  filled,  and  at  the  completion  of 
the  packing  the  amalgam  should  cut  as  though 
nearly  set. 

Another  and  excellent  method  where  applicable  is  to  shape  small 
pieces  of  half-vulcanized  rubber  and  cement  them  upon  broken  excava- 

FiG.  291. 


Mercury  expresser. 


Flagg's  wafering  pliers. 

tors,  and  use  them  as  pluggers  during  the 
The  fluid  cementing  amalgam  will  have  its 
about  the  sides  of  the  plugger. 

Still  another  method  is  to  fill  the  cavity 
cut  away  the  softened  portion,  and  complete 
gam.     Fillings  the  initial  portions  of  which 
paratively  dry  are  more  homogeneous  and 
and  crevice  than  when  more  fluid  amalgam 

21 


later  stages  of  the  filling, 
surplus  mercury  expressed 

more  than  half  full,  then 
the  filling  with  drier  amal- 
have  been  introduced  corn- 
are  less  likely  to  discolor 
has  been  used  to  begin  the 


322  PLASTIC  FILLING  MATERIALS. 

Hllint;-.  .Vn  exam i nation  of"  an  amalgam  fillinjji;  immediately  after  com- 
pletion will  show  the  marginal  portions  to  contain  the  softer  amalgam, 
the  harder  being  in  the  more  central  parts. 

The  too  common  })raetice  of  placing  in  the  prepared  cavity  sufficient 
amalgam  in  one  mass  to  nearly  or  quite  half  fill  it,  is  faulty.  By  no 
means  can  this  method  secure  the  accuracy  of  adaptation  of  filling 
material  to  cavity  walls  which  is  demanded  of  a  correct  filling. 

At  the  completion  of  the  packing  operation,  unless  the  filling  has 
been  finished  by  wafering,  the  surface  will  be  found  still  soft.  It  has 
been  recommended '  that  small  pieces  of  annealed  No.  1  gold  foil  be 
burnished  over  the  surface  of  the  amalgam,  until  no  more  gold  can  be 
amalgamated  by  this  means,  when  the  filling  will  be  found  quite  hard. 
The  indefinite  cementing  amalgam  has  combined  with  the  gold,  for 
wdiich  mercury  has  a  strong  affinity,  and  formed  a  distinct  amalgam 
upon  the  surface  of  the  filling  proper.  As  amalgams  of  gold  are  com- 
paratively soft,  it  is  advisal)le  to  first  fill  the  cavity  more  than  full,  apply 
the  gold  foil,  then  scrape  the  filling  down  to  the  cavity  margins.  Dr. 
Rhein's  procedure  is  to  fill  the  cavity  with  plastic  amalgam  and  rub  on 
the  pieces  of  gold  until  no  more  gold  is  amalgamated.  This  gold  amal- 
gam is  permitted  to  remain.  The  surplus  of  mercury  may  also  be  con- 
veniently removed  by  absorbing  it  from  the  surface  of  the  filling  by 
pieces  of  sponge  or  crystal  mat  gold. 

An  amalgam  filling  should  be  hard  enough  to  resist  cutting  before 
the  rubber  dam  is  removed. 

In  those  situations  where  the  rubber  dam  cannot  be  successfully 
employed,  it  is  the  accepted  practice  to  prepare  the  cavity,  sterilize  it, 
when  access  is  difficult  sealing  a  germicide  in  the  cavity  for  a  day;  next 
adjust  a  napkin,  and  having  mixed  a  submarine  amalgam  (one  contain- 
ing copper  and  a  high  percentage  of  silver),  the  cavity  is  dried  as  well 
as  possible  ;  a  piece  of  the  amalgam  is  then  carried  to  the  deepest  recess 
of  the  cavity  and  quickly  and  forcibly  compressed  with  a  mass  of 
bibulous  paper.  Another  piece  of  amalgam  is  added  and  compressed, 
driving  the  surplus  mercury  from  the  amalgam.  While  the  napkin  is 
in  position,  a  mass  of  temporary  stopping  (which  see)  is  softened  and 
placed  in  the  remainder  of  the  cavity.  A  knife  blade  passed  over  the 
edges  of  the  amalgam  will  remove  overhanging  portions.  At  a  subse- 
quent visit,  the  rubber  dam  is  adjusted,  the  temporary  stopping  is 
removed,  and  the  filling  completed  with  amalgam. 

If  the  operator  prefer,  the  rubber  dam  may  be  adjusted  at  once  and 
the  filling  completed  at  one  sitting  ;  the  former  method  is,  hoAvever,  pre- 
ferable, as  the  cervical  portion  of  the  filling  may  be  perfectly  finished, 
and  not  be  in  danger  of  displacement,  while  the  second  section  is  packed. 
1  Ottolengui's  Methods  of  Filling  Tenth,  "  Method  of  M.  L.  Rhein." 


USE  OF  AMALGAM.  323 

In  cavities  extending  beneath  the  gum,  and  opening  broadly  upon  a 
surface  of  a  tooth  where  discoloration  would  be  highly  objectionable, 
the  cervical  half  of  the  filling  is  made  of  a  submarine  amaluam  and  is 
completed  with  an  amalgam  containing  gold,  M'hich  will  retain  a  better 
color.  Should  the  external  face  of  the  filling  be  readily  visible  and  not 
subjected  to  the  stress  of  mastication,  its  outer  surface  is  made  of  a 
wafer  of  an  amalgam  containing  zinc,  known  as  a  facing  amalgam. 
Copper  amalgam  is  used,  when  used  at  all  (and  that  is  but  seldom), 
upon  the  distal  and  buccal  walls  of  third  molars,  in  cavities  extending 
under  the  gum  line,  which  are  difficult  of  access  and  to  sterilize,  and 
which  cannot  be  properly  dried. 

A  cavity  is  prepared  which  need  be  but  slightly  undercut.  A  pellet 
of  the  copper  amalgam  is  placed  in  an  iron  spoon  (Fig.  292)  held  above 

Fig.  292. 


Heating  spoon  for  copper  amalgam. 

a  Bunsen  flame  until  globules  of  mercury  appear  upon  its  surface,  when 
it  is  quickly  crushed  in  a  mortar  and  pounded  until  made  into  a  paste. 
There  can  be  no  objection  to  washing  the  soft  mass  in  aqua  ammonia  to 
dissolve  and  remove  oxids  which  later  form  discoloring  salts,  and  thus 
permit  a  chemical  union  of  the  metals  which  would  be  prevented  by 
their  presence.  A  napkin,  or  always  when  possible  the  rubber  dam, 
is  adjusted,  and  the  filling  inserted  in  sections.  At  the  end  of  the  oper- 
ation the  filling  should  be  firmly  compressed  with  a  broad-bladed  spatula. 

In  by  far  the  greater  number  of  cases  in  which  amalgam  was  at  one 
time  used  alone,  it  is  now  the  accepted  practice  to  place  a  lining  of  a 
zinc  cement,  and  add  the  amalgam  as  a  resistant  and  insoluble  covering. 

In  cavities  which  approach  the  pulp  the  same  precautions  are  taken 
for  the  prevention  of  thermal  shock  as  with  gold. 

The  most  difficult  class  of  cases  in  which  to  obtain  satisfactory  results 
with  amalgam  are  those  opening  alone  upon  the  approximal  surfaces  of 
bicuspids  and  molars.  While  it  is  true  that  amalgam  may  be  manip- 
ulated in  .spaces  impossible  with  gold  foil  even  in  soft  cvlinders,  it  is 
essential  that  sufficient  room  be  obtained  for  the  perfect  introduction  of 
the  material  and  its  subse([uent  trimming  and  })olishing ;  for  polishing 
is  quite  as  necessary  an  operation  with  amalgam  as  with  gold.  This 
space  is  obtained  either  through  wedging  or  by  cutting  through  the 
occlu.sal  face  of  the  tooth  into  the  cavity. 

Space  is  to  be  obtained  and  amalgam  packed  in  such  a  manner 
that  the  amalgam  at  the  completion  of  the  operation  shall   exhibit  no 


324  PLASTIC  FILLING  MATERIALS. 

evidence  of  pastiness.  To  insure  the  removal  of  the  excess  of  the  sol- 
vent, gold  foil  may  be  burnished  over  it  as  already  described  until  it 
requires  some  eifort  to  cut  the  mass  with  a  lancet  blade.  Amalgam 
when  set  is  more  difficult  to  cut  and  polish  than  gold  ;  the  greater  por- 
tion of  the  carving  is  therefore  done  at  the  same  sitting  as  the  filling, 
but  should  never  be  undertaken  while  the  filling  is  soft.  It  should  be 
in  such  a  condition  that  it  is  necessary  to  carve,  not  smear,  it  into  shape. 
A  suitable  cutting  instrument  of  the  form  of  Nos.  37  to  40  of  Flagg's 
set  (see  Fig.  286)  is  passed  first  across  the  cervical  border  of  the  filling, 
removing  any  excess  due  to  imperfect  contact  of  the  matrix  witli  the 
cervical  margin  of  the  cavity ;  next  the  lateral  borders  are  carved,  and 
then  the  masticating  surface.  The  body  of  the  filling  is  left  full,  so  that 
after  two  days,  when  the  filling  receives  its  final  dressing  and  polishing 
with  cuttlefish  disks,  strips,  pumice,  etc.,  the  filling  will  be  reduced  to 
correct  contour.  A  polished  amalgam  filling  w^ill  retain  an  untarnished 
surface  when  an  unpolished  one  will  discolor  very  objectionably. 

Many  of  the  cases  in  which  it  was  at  one  time    the  usual  prac- 
tice   to    fill    or    restore    almost   entire    tooth    crowns    with    amalgam, 
Fig.  293.  are    trimmed    down,  shaped,    and    artificial 

crowns  applied.  One  class  of  cases  is  fre- 
quently seen  in  which  the  indication  is  for 
an  enormous  amalgam  filling  rather  than  an 
artificial  crown  ;  this  is,  the  loss  of  the  dis- 
tal half  of  the  crown  of  a  molar.  As  a 
rule  the  teeth  are  pulpless,  or  it  is  necessary 
^   ,     ,.       „ ,  ,       .,,,    to  devitalize  the  pulp.     The  ai)])earance  of 

Restoration  of  lower  molar  with  i       r  i  i 

amalgam.  the  crown  after  the  removal  of  carious  den- 

tin and  cutting  away  frail  enamel  walls  is  seen  in  Fig.  293. 

A  Herbst  matrix  is  fitted,  closely  embracing  all  the  margins  of  the 
cavity.  The  rubber  dam  is  adjusted.  It  is  of  course  understood  that 
the  root  canals  have  been  properly  sterilized  and  filled.  The  posterior 
canal  is  drilled  out  fi)r  about  \  in.  and  screw-tapped.  A  thin  solution 
of  zinc  phosphate  is  mixed  and  the  tip  of  a  screw  to  fit  the  tapped 
root  has  its  point  dipped  into  the  cement,  and  then  quickly  screwed 
into  place.  The  amalgam  is  packed  in  larger  masses  than  usual,  using 
bibulous  paper  to  compress  it  about  the  screw  and  into  such  scant 
undercuts  as  may  be  secured  in  the  anterior  portion  of  the  tooth.  The 
filling  is  completed  with  amalgam  wafers. 

Such  a  filling  should  be  well  set  before  the  rubber  dam  is  removed. 
The  upper  surface  is  carved  into  cusps  and  sulci  to  occlude  properly 
with  the  antagonizing  teeth.  The  matrix  should  remain  for  twenty- 
four  hours,  when  it  may  be  split  and  removed.  If  the  matrix  has  been 
exactly  adjusted  there  should  be  no  trimming  of  the  margins  required, 


USE  OF  AMALGAM. 


325 


no  carving  of  contour,  and  no  smoothing,  the  amalgam  being  ready  for 
polishing  strips.  The  occlusal  surface  is  smoothed  and  polished  with 
moosehide  points  and  pumice,  using  a  stiif  brush  to  polish  the  sulci. 

Finishing-. — The  process  of  finishing  hard  amalgam  fillings  is  simi- 
lar to  that  of  finishing  gold.  For  example:  a  compound  cavity  occu- 
pying the  approximal  and  occlusal  faces  of  a  molar.  A  fine  saw  is 
placed  in  a  frame  as  in   Fig.  294,  but  set  to  draw-cut  with   its  teeth 

Fig.  294. 


The  Kaeber  saw  frame. 

pointing  toward  the  frame.  The  blade  is  passed  above  the  cervical 
margin  of  the  filling,  engaging  any  projecting  amalgam,  which  is  then 
sawn  oif.  It  is  just  as  essential  with  an  amalgam  as  with  a  gold  filling 
that  the  cervical  edge  should  be  exactly  flush. 

The  lateral  margins  of  the  filling  are  next  carved  smooth  ;  strips  of 
emery  cloth  are  passed  into  the  interdental  space  and  the  filling  smoothed 
and  rounded,  completing  this  portion  of  the  operation  with  emery  strips 
of  the  finest  grit. 

Linen  tapes  or  metal  polishing  strips  are  next  charged  with  pumice 
and  passed  over  the  surfaces  until  they  are  smooth  and  the  margins  are 
perfect.  The  occlusal  portion  is  polished  by  means  of  rubber  or  moose- 
hide  points  and  pumice. 

Should  it  be  a  plain  approximal  filling,  not  a  "  contour,"  the  saw  is 
used  to  cut  away  surplus  amalgam,  and  the  polishing  accomplished  by 
means  of  disks  and  powders. 

Fillings  upon  the  buccal  surfaces  of  teeth  are  smoothed  by  means 
of  disks  and  polished  with  rubber  cups  or  disks  and  pumice. 

Gutta-percha. 

Origin. — The  gutta-percha  of  commerce  is  the  coagulated  juice  of 
the  Isunaudra  gutta,  a  tree  of  the  order  of  ISapotacece.  The  juice  is 
found  in  all  trees  of  this  order,  but  some  specimens  are  of  much  higher 
value  than  others.  That  from  Borneo  is  regarded  by  manufacturers  as 
being  inferior  ;  it  is  the  variety  from  which  the  name  is  derived — Malay, 
gatah  or  gittaJi,  gum,  and  pertja,  a  tree.  The  gutta  Tuban  from  Singa- 
pore is  regarded  as  a  superior  variety. 


326  PLASTIC  FILLING  MATERIALS. 

The  mode  of  securing  the  juice  is  by  tapping  tlie  cambium  layer  of 
the  tree  and  catching  tlie  juice  as  it  exudes.  From  this  stage  to  its 
formation  into  sheets  it  undergoes  several  processes  (see  works  on  gutta- 
percha);  it  is  possible  that  in  some  of  these  operations  it  may  have  its 
texture  injured  by  overheating. 

"The  purified  gutta-percha  probably  consists  of  a  hydrocarbon  (pure 
gutta)  having  the  formula  CiuH,g ;  albane,  C,oH,gO ;  fluavile,  C^dHg^O,; 
and  a  variable  compound  named  guttune.  Pure  gutta  possesses  all  the 
good  qualities  of  gutta-percha  in  a  much  enhanced  degree,  becoming 
soft  and  plastic  on  heating  and  hard  and  tenacious  on  cooling  without 
being  in  the  least  brittle.  The  resins  appear  to  be  simply  accessory 
components  which  have  a  decidedly  detrimental  eifect  when  they  ]ire- 
ponderate.  Water,  wood,  fibers,  bark,  sand,  etc.,  occur  as  mechanical 
impurities  of  gutta-percha."     (Obach.) 

History. — Gutta-percha  was  introduced  into  dental  practice  as  a  fill- 
ing material  about  the  year  1847.  Soon  after  this  a  secret  preparation 
was  introduced  by  a  Dr.  Hill,  which  received  his  name.  Numerous 
alleged  analyses  of  Hill's  stopping  have  been  given,  all  of  which  are 
untrustworthy.  It  was  found  to  subserve  so  useful  a  ])urpose  that  it 
received  the  tribute  of  wide  imitation  ;  in  fact,  the  white  gutta-percha 
preparations  of  the  present  day  had  their  foundation  in  this  imitation. 
There  is  no  entirely  trustworthy  evidence  that  the  original  was  superior 
to  the  best  of  contemporary  preparations. 

As  at  present  employed  as  a  filling  material  gutta-percha  is  in  two 
forms,  the  first  the  well-known  pink  gutta-percha  base  plate,  which  is 
colored  by  the  insoluble  sulfid  of  mercury,  the  second  the  white  prep- 
arations, made  firmer  in  texture  by  additions  of  the  soluble  zinc  oxid. 
The  specimens  of  crude  gum  differ  as  to  the  amount  of  heat  required 
to  soften  them  to  an  equal  degree.  Dr.  Flagg  ^  states  that  the  speci- 
mens requiring  the  greatest  degrees  of  heat  for  softening,  prior  to  the 
addition  of  the  zinc  oxid,  afford  the  best  dental  gutta-perchas.  The 
method  of  making  the  gutta-percha  of  dentistry  is  by  softening  a  mass 
of  the  brownish-yellow  gum  on  a  slab  which  has  been  heated  over  boil- 
ing water,  and  driving  zinc  oxid  into  the  softened  mass  by  a  process 
of  kneading,  using  a  wedge-shaped  steel  instrument  as  the  kneader.  It 
requires  infinite  patience  and  much  time  to  distribute  the  powder  evenly 
throughout  the  mass.  Overheating  the  material  at  any  stage  of  its 
manufacture  or  manipulation  is  ruinous  to  its  texture. 

Classes. — Gutta-perchas  are  divided  into  three  classes  according  to 
the  temperature  of  softening  :  Low  heat,  softening  below  200°  F.  3Ie- 
dium  heat,  becomes  plastic  at  200°  to  210°  F.  Hif/h  heat,  210°  to  218°  F. 
The  low-heat  specimens  contain  1  part  by  weight  of  gutta-percha  to  4 

^  Plastics  and  Plastic  Filling. 


GUTTA-PERCHA.  327 

of  zinc  oxid  ;  in  medium-heat  the  ratio  is  1  to  6  or  7  ;  and  in  the  high- 
heat  specimens  the  gutta-percha  is  ahnost  saturated  with  zinc  oxid. 

Physical  Properties. — Gutta-percha  is  an  almost  perfect  non-con- 
ductor both  of  heat  and  electricity.  It  is  less  hard  and  rigid  than  any 
other  filling  material.  It  contracts  in  hardening,  i.  e.  cooling.  Softened 
masses  of  it  are  coherent  when  dry,  but  not  when  wet.  Its  color  may 
be  made  to  resemble  that  of  the  teeth.  To  vital  tissues  it  is  the  most 
bland,  unirritating  filling  material  known. 

After  it  has  served  as  a  filling  for  a  greater  or  less  period  it  is  found 
to  have  increased  in  hardness  and  difficulty  of  softening,  and  its  surface, 
and  perhaps  its  substance,  has  become  porous  in  variable  degree.  The 
increased  hardness  is  observed  in  such  situations  as  those  in  which 
putrefactive  decomposition  occurs ;  that  is,  in  places  where  there  is  an 
evolution  of  hydrogen  sulfid  ;  the  gutta-percha  apparently  undergoes  a 
species  of  vulcanization.  It  becomes  somewhat  porous  in  those  situa- 
tions where  the  formation  of  a  solvent  is  active  (lactic  acid),  which 
abstracts  the  soluble  zinc  oxid  from  the  mass.  The  pink  variety  con- 
taining the  insoluble  mercury  sulfid  does  not  become  porous,  but  wears 
with  a  comparatively  smooth  surface  w^hen  subjected  to  attrition. 

Examining  in  detail  these  several  physical  properties  it  will  be  noted 
that  gutta-percha  has  but  one  property  in  common  with  gold — its  insol- 
ubility. Its  rational  employment  is  therefore  in  such  situations  and 
conditions  as  those  in  which  the  use  of  gold  is  contraindicated. 

Indications  for  its  Employment. — First,  in  its  several  forms  it  is 
employed  as  a  temporary  filling  material  for  both  the  temporary  and 
permanent  teeth.  Owing  to  its  non-conductivity  it  is  employed  near 
the  pulp  ;  its  insolubility  recommends  its  use  at  the  cervical  margins  of 
cavities,  particularly  in  the  buccal  cavities  of  molars  which  do  not 
extend  to  the  masticating  surface,  where  the  non-resistance  of  the 
material  would  cause  its  rapid  wasting. 

This  is  the  most  common  of  the  situations  in  which  gutta-percha  is 
applied  :  very  deep  cavities  upon  the  buccal  surfaces  of  molars,  extend- 
ing beneath  the  gum,  and  having  ragged  enamel  margins,  the  orifice 
of  the  cavity  being  much  smaller  than  its  body.  Owing  to  its  non- 
irritating  quality,  the  condition  of  the  gum  in  contact  with  a  gutta- 
percha filling  remains  normal. 

It  is  used  in  approximal  cavities  of  the  anterior  teeth  which  have  a 
similar  form  to  those  just  described  ;  also  in  labial  cavities,  particularly 
when  these  teeth  are  in  any  degree  loose.  For  example  :  in  a  cavity 
opening  alone  upon  the  distal  wall  of  a  canine  tooth  the  carious  process 
has  almost  invaded  the  pulp,  the  enamel  walls  unsupported  by  dentin 
still  retain  their  form  and  have  a  good  texture. 

Pink  base  plate  is  invaluable  for  the  temporary  filling  of  spaces  after 


328 


PLASTIC  FILLING  MATERIALS. 


wedging;  and  :il-;()  the  cavities  to  be  subsequently  tilled  with  metal.  A 
mass  of  the  material  may  l)e  packed  into  such  spaces  and  be  permitted 
to  remain  for  months  if  desired,  the  gum  in  contact  with  it  after  its 
prolonged  presence  exhibiting  no  indications  of  irritation,  Masses  of 
gutta-perc^ha  may  be  packed  in  interdental  spaces  where  there  is  not 
sufficient  space  for  the  introduction  of  contour  fillings,  with  the  purjwse 
of  having  the  teeth  gradually  separated  by  the  impact  of  mastication; 
the  gutta-percha  acts  as  a  persistent  and  very  gradual  wedge. 

When  it  has  been  determined  that  an  excavated  cavity  is  unfit  for 
the  reception  of  a  permanent  filling,  gutta-percha  is  the  filling  material 
par  excellence. 

Although  it  is  stated  that  gutta-percha  shrinks  markedly  in  harden- 


FiG.  295. 


Fluf 


;\itta-percha  softener  and  tool-heater. 


ing,  cavities  in  which  it  has  been  properly  placed  exhibit  no  evidences 
of  softening  after  the  material  has  been  worn  for  months,  or  it  may  be 


OUTTA-PERCHA. 


329 


Fig.  296. 


for  years.     Particularly  is  this  true  when  the  pink  variety  has  been 
employed  and  the  method  of  introduction  is  correct. 

Mode  of  Softening-. — Gutta-percha  should  never 
be  heated  beyond  a  point  which  permits  of  accurate 
adaptation  to  undercuts  and  frail  walls.  The  soften- 
ing should  be  gradual.  Any  heat  in  excess  of  this  is 
not  only  harmful  but  ruinous. 

For  its  proper  softening  some  device  is  necessary 
which  shall  permit  of  this  type  and  degree  of  heating 
(see  Figs.  295-297,  306). 

Fig.  295  illustrates  the  heater  of  Dr.  Flagg.  There 
are  three  metallic  shelves,  the  highest  of  which  receives 
the  least  amount  of  heat,  and  is  designed  for  softening 
low-heat  gutta-percha.  The  second  shelf  is  for  the 
softening  of  high-heat  specimens.  The  lowest  shelf 
and  rack  support  the  packing  instruments,  which  are 
kept  at  a  higher  temperature  than  the  filling  material. 

Fig.  296  illustrates  a  device  of  Dr.  L.  A.  Faught 
for  the  packing  of  gutta-percha.  The  heating  wires 
connect  at  the  bases  of  the  instrument  points,  which 
are  of  aluminum,  and  sufficient  heat  is  conveyed  to  the 
gutta-percha  to  maintain  it  in  a  plastic  state  during  the 
packing  operation. 

Instruments. — As  a  rule  the  instruments  used  in 
packing  gutta-percha  are  too  large  and  the  material 
itself  is  used  in  too  large  pieces.  If  the  cavity  is  of 
considerable  extent,  and  usually  it  is,  the  filling  should 
be  introduced  in  four  or  more  pieces.  It  is  preferable 
to  warm  all  the  packing  instruments  so  that  the  gutta- 
percha will  remain  plastic  until  perfectly  adapted. 

Manipulation. — The  rubber  dam  having  been  ad- 
justed, the  cavity  excavated  and  sterilized,  the  frail 
enamel   edges  broken  away,  without  p„.   297. 

any  particular  object  of  margin  form- 
ing, but  to  gain  space,  the  cavity  is 
dried  for  the  reception  of  the  gutta- 
percha. The  field  of  operation  should 
be  dry,  in  order  that  each  additional 
piece  of  gutta-percha  shall  adhere  to     Order    of    placing 

1    "  1  •    1     • ,  11         i    1         gutta-percha  pellets. 

its  predecessor,  wluch  it  would  not  do 
if  wet.    A  softened  pellet  is  taken  upon  the  point  of  a 
probe  and  placed  in  the  most  inaccessible  portion  of 
the  cavity  and  tapped  into  accurate  contact  with  the  tooth  walls  (by 


Dr.  Faughi's  L'lectric 
heater. 


330  PLASTIC  FILLING   MATERIALS. 

means  of  tlic  corkscrew  plugger  No.  32  or  No.  33),  as  shown  in 
No.  1  of  Fig.  21)7.  A  second  pellet  is  added  (No.  2)  and  similarly 
manipulated.  The  Nos.  3,  4  pellets  are  packed  in  the  order  shown  in 
the  figure.  In  adding  the  last  piece  broad-faced  instruments  are  used, 
adapting  the  gutta-percha  accurately  to  the  margins  of  the  cavity.  The 
softened  gutta-percha  may  be  made  to  adhere  better  to  the  walls  of  the 
cavity  if  these  be  first  coated  with  one  of  the  lining  varnishes. 

Another  method  of  manipulation  is  to  line  the  walls  of  the  cavity 
Avith  pellets  vintil  a  cylindrical  cavity  remains.  A  cylinder  of  gutta- 
percha of  that  size  is  nearly  softened  and  pressed  firmly  into  the  cavity 
by  means  of  a  broad  spatula. 

Should  the  cavity  be  very  deep,  the  pulp  almost  exposed,  the  por- 
tion of  dentin  overlying  the  pulp  is  to  l)e  covered  ])y  a  thin  pellet  of  low- 
heat  gutta-percha  softened  sufficiently  to  permit  of  adaptation.  A  disk 
of  pink  gutta-percha  base  plate  answers  admirably  for  this  purpose. 

The  use  of  one  of  the  lining  varnishes,  noted  at  page  257,  especially 
the  cellulose  solution  known  as  kristaline,  previous  to  placing  the  pellets, 
will  insure  their  adhesion  to  the  cavity  walls  and  prevent  rocking  or 
tipping  of  the  mass  of  gutta-percha  during  the  operation  of  its  insertion. 
In  order  to  secure  the  best  results  the  kristaline  solution  should  be  thin 
when  applied,  and  the  solvent  completely  evaporated  by  blasts  of  warm 
air  before  any  attempt  is  made  to  introduce  the  gutta-percha,  for  unless 
the  varnish  lining  is  fully  hardened  the  j)ellets  will  not  strongly  adhere 
to  the  surface  so  treated. 

Dr.  How's  Improved  Gutta-percha  Filling-s. — Dr.  W.  Storer  How  ^ 
has  published  a  method  of  packing  gutta-percha  which  is  as  excellent 
as  rational,  when  the  directions  given  are  closely  followed : 

"  Many  approximal  cavities  like  C,  Figs.  298,  299,  may  well  be 

Fig.  298.  Fig.  299. 


-fii" 


Approximal  cavities. 

filled  with  gutta-percha,  and  such  as  C,  Fig.  299,  where  a  gold  filling 
would  show  through  the  thin  enamel  front,  can  better  be  filled  with 
suitable  gutta-percha.  The  section.  Fig.  300,  shows  the  angles  A,  A', 
which  should  be  given  the  enamel-edges  when  ])racticable,  and  in  any 
case  the  enamel-margin  should  have  a  squarely  defined  angle  at  its 
surface  border. 

"  Cervico-labial   or   buccal  cavities,  as   shown    in    Figs.   301-305, 
'  Dental  Cosmos,  1892,  vol.  xxxiv.  p.  281. 


G  UTTA-PERCHA .  331 

admit  of  permanent  gutta-percha   fillings.      Of  course  due  attention 
Fig.  301.  Fig.  302.  Fig.  308.  Fig.  304.  Fig.  305. 


rervicD-labiiil  iiiul  liure.-il  cavities. 


must  be  given  to  the  retention  of  the  fillings  by  enlarging  the  interior 
walls  of  the  cavities  when  they  have  not  already  such  expansions. 
After  suitably  preparing  the  cavity,  it  should  be  made  as  dry  as  possible 
and  so  kept.  The  problem  of  conveniently  and  properly  softening 
pellets  of  gutta-percha  has  been  solved  by  the  production  of  the  ther- 
moscopic  heater  shown  in  Fig.  306,  which  approximates  the  exact  size 

Fig.  30tj. 


Thermoscopic  heater  for  gutta-percha. 

of  the  device.  The  heater  is  in  this  instance  made  of  steatite,  because 
of  its  heat-retaining  property  and  the  desirable  physical  qualities  of  its 
surface.  The  handle  is  of  wood,  at  the  opposite  end  from  which,  in 
the  centre  of  the  circular  recess,  is  a  small  disk  (.4)  of  metal,  fusible  at 
about  212'^  F.  On  the  heater  near  the  metal  a  suitable  number  of 
gutta-percha  pellets,  as  1,  1,  are  placed,  and  the  heater  held  over  the 
flame  of  the  annealing  lamp  or  burner  (as  in  the  illustration)  until  the 
fusible  metal  melts,  M'heii  the  heater  is  placed  on  a  piece  of  cardboard 
(or  an  empty  foil-book),  and  the  gutta-percha  will  be  found  to  be  })rop- 
erly  softened.  The  steatite  plaque  retains  the  heat  long  enough  for  an 
ordinary  operation,  but  if  the  metal  meantime  loses  its  fluidity  and  so 


332  PLASTIC  FILLING  MATERIALS. 

indicates  a  lowrring  of  the  standard  heat,  it  may  he  cjuickly  restored 
by  a  moment's  holding  of  the  heater  over  tlie  llaine,  -wliich  will  again 
fuse  the  metal. 

"When  the  flame  is  a])plied  directly  under  the  metal,  as  in  the  illus- 
tration, the  material  placed  at  1  will,  when  the  metal  is  seen  to  be  fused, 
be  at  the  heat  of  near  208°  F.,  while  the  pellets  at  2  will  be  heated  to 
about  200°,  those  at  3  and  4  to  near  194°  and  180°  respectively.  Of 
course  the  location  of  the  heat-source  will  |)r()(lu('e  corresponding  varia- 
tions in  the  relative  temperatures  of  the  materials  as  severally  situated  \ 
but  with  a  visibly  definite  standard  such  as  the  metal  A,  having  a  known 
fusing-point,  the  desired  degree  of  heat  may  repeatedly  be  produced  at 
any  place  on  the  receiving  surface  of  the  heater.  A  few  seconds'  contin- 
uance of  the  heater  over  the  flame,  after  the  metal  has  melted,  will  raise 
the  surface  heat  to  212°  or  215°,  as  the  case  may  be  ;  but  as  a  suitable 
indicator  for  a  high-heat  stopping,  a  button  {B)  of  metal  fusing  at  230° 
is  provided  as  a  substitute  for  A,  which  is  first  melted  and  poured  out 
on  a  piece  of  clean  paper,  the  heater  cavity  being  undercut  so  that 
when  cold  the  metal  cannot  be  shaken  out.  The  boiling  of  a  few 
drops  of  water  in  the  heater  cavity  will  likewise  serve  to  indicate 
the  proper  temperature,  but  the  fusible  metal  is  in  every  way  pref- 
erable.    The   best   plan  is  to  hold  the   heater  over  the  flame  until  the 

^      „,,^  metal    melts,  set    down    the    heater,    blow    hot   air 

Fig.  307.  ,  '  .  ^         ^    \  •  -i 

_^,^j^^^^,siw-    -ri^^      luto  the  previously   prepared   and   dry  cavity  until 

j        yC/^  I  the  tooth  is  sensibly  warm,  hold  the  heater  again 

/  ,       I  //     I        I    over  the  flame  to  melt  the  metal,  and  then  with  a 

~~^""^/^/        ~^  suitable  broad  and  cold  instrument  pick  from  the 

/ 1  heater  a  pellet  or  group  of  pellets  suificient  to  a  little 

/J  more  than  fill  the  cavity,  and  by  a  quick,  firm,  rock- 

Trimming  margins   of    iug  pressure  force  the  mass  into  the  cavity  as  if  it 

gutta-percim  filling.  ^^r^rQ^^Q  sought  to  take  an  impression  of  the  same. 
Then  dip  the  instrument  into  ice-water,  wipe  dry,  and  hold  it  firmly 
against  the  filling  for  one  or  more  minutes,  after  which  with  a  keen- 
edged  thin  blade  pare  off*  the  surplus,  cutting  from  the  centre  obliquely 
toward  the  margin,  as  in  Fig.  307,  taking  great  care  that  the  filling  B 
shall  be  flush  with  the  cavity  margin  at  every  point,  as  at  A,  A',  Figs. 
308  and  309. 

"  Access  to  approximal  cavities,  as  C,  C,  Figs.  298  and  299,  will 
seldom  permit  the  instantaneous  mass-method  just  described,  but  in 
many  such  cases  a  warm,  broad,  flat  blade,  as  stiff  as  the  space  will 
admit,  can  by  repeated  quick  pressures  be  made  to  squeeze  the  soft  mass 
into  the  cavity  of  the  warmed  tooth,  and  be  instantly  followed  by  a  very 
thin  strip  of  metal  held  tightly  in  both  hands  and  wrapped  with  hard 
pressure  over  the  filling  around  that  side  of  the  tooth,  to  both  condense 


GUTTA-PERCHA. 


333 


and  contour  the  plastic  and  produce  the  chjsest  adaptation  of  the 
material  to  all  parts  of  the  cavity  walls. 

"  There  is  good  reason  for  the  belief  that  the  common  mode  of  suc- 
cessively introducing  small  pieces  of  imperfectly  softened  gutta-percha 
into  a  com]iaratively  cold  cavity,  and  employing  instrument  points  more 
or  less  heated  for  packing  the  cooled  })lastic  against  one  side  of  the 
cavity  after  the  other,  must  in  the  nature  of  the  case  result  in  a  leaky 
filling,  such  as  gutta-percha  is  connnonly  said  to  make,  whereas  the 
defect  is  due  not  to  the  material,  but  to  its  inconsiderate  manipulator. 

"  In  order  to  definitely  determine  whether  or  not  suitably  softened 
gutta-percha  inserted  by  the  mass-method  Avill  make  a  moisture-tight 
filling,  some  porcelain  teeth  of  natural  sizes  and  forms  were  made,  hav- 


FiG.  311. 


Fig.  312.        Fig.  313. 
d-K^-  A'  ^ 


i 


A' 


%^ 


ing  cut  in  them,  prior  to  baking,  cavities  of  the  class  shown  in  Figs. 
298-305.  These  cavities  have  been  filled  with  gutta-percha,  leaving 
a  surplus  over  the  margins  as  at  o,  a',  Fig.  310,  and  when  quite  cool 
paring  them  flush  as  at  A,  A',  Figs.  308  and  309,  and  after  several  days' 
immersion  in  dilute  aniline  ink,  the  fillings  have  been  removed  without 
a  trace  of  color  showing  on  the  walls  of  either  the  fillings  or  the  cavi- 
ties. The  only  exceptions  have  been  where  the  margins  were  rounded, 
as  at  a,  a' ,  Fig.  310,  and  the  fillings  not  cut  below  them  as  shown,  but 
left  feather-edged  as  at  d,  cV ,  Fig.  312.  In  these  few  instances  discolor- 
ations  were  found  under  the  laps,  but  in  no  case  extending  farther  than 
to  A',  A',  Fig.  313.  The  tests  prove  that  under  conditions  as  nearly 
practically  parallel  as  extra-oral  tests  can  well  be,  gutta-percha  fillings 
properly  made  will  exclude  external  moisture.  Obviously,  it  is  better 
to  pare  the  filling  below  the  enamel-slo])es,  as  in  Figs.  311  and  313, 
than  to  leave  it  overlapping,  as  in  Figs.  310  and  312.  For  a  final  finish 
use  a  rapidly  revolved,  lightly  touching  cuttlefish-paper  disk,  fi)llowed 
by  a  wisp  of  bibulous  paper  or  piece  of  tape  wet  Avith  chloro-percha, 
applied  for  but  an  instant,  to  glaze  the  .surface  of  the  filling. 

"  In  the  case  of  a  very  thin  enamel  front  like  that  of  Fig.  299,  that 
part  of  the  cavity  C  may  be  varnished  with  thin  chloro-percha  and  dried 
with  hot  air  just  prior  to  filling  it  as  before  said.  It  might  first  be 
thinly  coated  with  a  tinted  oxyphosphatc  or  oxychlorid  of  zinc,  which 


334  PLASTIC  FILLING  MATERIALS. 

should  1)0  given  ani])lc  time  to  harden  before  plaein^i^  tlic  gutta-percha. 
Indeed,  it  is  a  fundamental  feature  of  good  gutta-percha 
work  that  while  one  cannot  operate  too  rapidly  when 
the  plastic  is  at  its  proper  temperature,  the  preparatory 
and  completing  processes  should  be  given  as  much  time, 
care,  and  close  scrutiny  as  more  elaborate  and  often  less 
enduring  gold  operations.  There  is  furthermore  room 
for  the  exercise  of  the  artistic  faculty  in  having  at  hand  chloro-percha, 
or  cellulose  varnish  of  varied  colors,  with  which,  by  means  of  a  small 
brush,  a  gutta-percha  filling  as  B,  Fig.  301,  and  one  in  the  like  cavity 
C,  may  be  given  an  inconspicuous  shade,  and  the  painting  be  renewed 
from  time  to  time,  if  that  be  necessary  by  reason  of  wear.  Fig.  314  is 
a  sectional  view  of  fillings  like  7?,  C,  Fig.  301." 

Finishing-  Gutta-percha  Fillings. — If  a  gutta-percha  filling  has 
been  packed  with  the  proper  amount  of  care  and  skill,  it  should  require 
but  little  trimming.  It  should  be  undisturbed  until  cold.  Its  harden- 
ing may  be  hastened  and  intensified  by  holding  ice-water  in  contact 
with  it  for  a  few  moments. 

The  portions  overlying  the  margins  are  to  be  trimmed  wdth  extremely 
sharp  lancets  or  by  warm  blades.  Every  cut  should  remove  a  little  of 
the  surplus  material,  never  a  mass  of  it,  and  should  be  made  toward  the 
cavity  margins,  never  away  from  them.  The  filling  should  have  been 
made  so  that  no  fulness  is  present  to  require  reducing. 

It  is  a  general  practice  to  give  a  smooth  face  to  a  gutta-percha  filling 
by  wiping  it  with  a  tape  slightly  moistened,  not  wet,  with  chloroform. 
The  surface  produced  by  this  means,  although  smooth,  does  not  retain  its 
integrity  so  well  as  when  the  surface  is  formed  by  cutting. 

The  use  of  gutta-percha  as  a  canal  filling  is  discussed  in  Chap.  XVII. 

Basic  Zinc  Cements. 

Zinc  Oxychlorid. — The  basic  zinc  cements  employed  in  dentistry  are 
the  oxychlorid  and  the  phosphate ;  the  oxysulfate  should  also  be  included. 

The  oxychlorid  is  formed  by  the  combination  of  calcined  and  pul- 
verized zinc  oxid  w^th  a  solution  of  zinc  chlorid  : 

ZnO  +  ZnCL  +  H^O  =  2ZnClHO. 

This  compound  was  introduced  as  a  dental  filling  material  about  1850, 
its  hardness,  whiteness,  and  apparent  insolubility  recommending  it  for 
that  purpose.  It  required  no  lengthy  period  of  time  to  demonstrate 
that  as  a  filling  material  per  se  it  was  unfit  for  use.  It  disintegrated 
rapidly  and  was  not  free  from  shrinkage. 

Properties. — Freshly  mixed,  this  material  is  irritating  to  vital 
tissues  with  which  it  is  brought  in  contact ;  applied  close  to  or  upon  an 
exposed  pulp  it  may  be  productive  of  a  transient  or  a  persistent  irritation, 


BASIC  ZINC  CEMENTS.  335 

or  even  inflammation.  The  extent  of  the  irritation  is  largely  governed 
by  the  fluidity  of  the  cement  paste,  /.  e.  the  amount  of  zinc  chlorid  present. 

It  sets  in  flfteen  minutes  sufficiently  to  permit  the  packing  upon  it 
of  an  amalgam,  and  in  half  an  hour  a  gold  filling.  After  setting  it  is 
whiter  though  less  hard  than  the  zinc  phosphate;  it  shrinks,  particularly 
when  used  in  large  masses.  It  is  a  poor  thermal  conductor,  and,  like 
all  bodies  containing  zinc  oxid,  is  soluble  in  lactic  acid — the  usual  sol- 
vent in  the  oral  cavity.  These  several  features  are  at  present  regarded 
as  limiting  the  application  of  oxychlorid  to — first,  a  lining  material  for 
carious  cavities  over  which  the  insoluble  filling  proper  is  to  be  placed  ; 
second,  as  a  root-filling  material  (its  use  in  this  connection  is  discussed 
in  Chapter  XVII.).  It  is  to  be  noted  that  the  cement  retains  after 
setting  an  antiseptic  power  for  a  greater  or  less  period. 

Use. — Zinc  oxychlorid  is  usually  employed  as  a  lining  material  in 
teeth  having  what  is  known  as  poor  structure — those  in  which  caries 
proceeds  to  great  depths  without  external  evidence  of  the  extent  of 
invasion.  After  these  cavities  have  been  partially  excavated  it  is  found 
that  further  excavation  and  the  removal  of  the  deepest  layers  of  the 
leathery  dentin  which  appear  to  have  retained  sensitivity  would  prob- 
ably uncover  the  pulp  ;  it  may  be  that  the.  pulp  has  given  subjective 
evidence  of  a  mild  attack  of  active  hyperemia. 

In  such  cases  the  deepest  layer  of  the  partially  disorganized  dentin 
is  permitted  to  remain  and  is  subjected  to  the  prolonged — fifteen  minutes 
or  longer — contact  of  hydrogen  peroxid  in  the  25  per  cent,  ethereal 
solution  (caustic  pyrozone),  5  per  cent,  aqueous  solution  of  formalin, 
or  preferal)ly  a  saturated  solution  of  thymol  in  alcohol.  The  cavity 
walls  are  well  dried  with  bibulous  paper  and  the  warm-air  blast. 
Upon  a  mixing  slab  (see  Fig.  315),  a  drop  or  two  of  the  zinc  chlorid 
is  placed,  and  beside  it  a  quantity  of  the  zinc  oxid  powder.  The 
powder  is  gradually  incorporated  with  the  fluid  by  means  of  a  spatula 
until  a  creamy  paste  is  made.  A  number  of  balls  of  bibulous  paper 
are  to  be  at  hand.  A  portion  of  the  paste  is  taken  upon  the  end  of 
an  instrument  and  placed  in  the  cavity,  where  it  is  quickly  pressed  into 
a  layer  against  the  cavity  walls  by  means  of  the  balls  of  bibulous  paper. 
The  walls  are  to  be  covered  to  a  uniform  depth  of  about  one-sixteenth 
of  an  inch.  The  prompt  application  of  the  bibulous  paper  usually  pre- 
vents any  irritation  due  to  the  contact  of  the  oxychlorid  with  the  dentin 
overlying  the  pulp.  Should  the  cavity  be  very  deep  it  is  advisable  to 
protect  the  pulp  by  interposing  a  film  of  ethereal  varnish  between  the 
oxychlorid  and  the  dentin  over  the  pulp. 

At  the  completion  of  the  lining  operation,  the  margins  of  the  cavities 
are  to  be  cleansed  of  the  oxychlorid  and  the  filling  completed  with  the 
material  indicated. 


336  PLASTIC  FILLING  MATERIALS. 

Zinc  oxychlorid  as  an  ohtunding  agent  in  tlie  treatment  of  hyjxT- 
sensitive  dentin  is  of  considerable  value,  and  its  use  for  tiiat  jjurpose  is 
described  in  Chapter  VII. 

The  use  of  zinc  oxychlorid  as  a  canal  filling,  and  the  mode  of  using 
it,  are  discussed  in  Chapter  XVII. 

The  powder  of  this  cement  is  made  of  zinc  oxid  calcined  and  pow- 
dered, to  which  have  been  added  substances  (borax,  silica,  etc.)  which 
affect  its  properties  but  little  if  at  all. 

T\\Q.  fluid  is  made  by  dissolving  pure  zinc  or  its  oxid  in  hydrochloric 
acid  to  the  point  of  saturation  ;  or,  by  making  a  solution  of  zinc  chlorid 
4  parts,  water  3  parts,  and  filtering  the  solution. 

The  use  and  effects  of  zinc  oxychlorid  as  a  pulp  capping  are  dis- 
cussed in  Chapter  XVI. 

Zinc  Phosphate. — These  cements  are  nominally  a  combination  of 
calcined  zinc  oxid  with  a  syrupy  solution  of  orthophosphoric  acid  : 

3ZnO  +  2H3PO,  =  Zn3(POj2  +  3H2O, 

although  their  actual  composition  is  more  variable  than  that  of  any  other 
filling  material.  Both  base  and  solvent  commonly  contain  impurities — 
those  of  the  base  owing  to  lack  of  discrimination,  or  worse,  in  the  source 
of  the  oxid.  Many  of  the  impurities  of  the  phosphoric  acid  are  due 
primarily  to  the  well-known  inconstancy  of  the  acid  itself,  and  others  to 
the  mode  of  its  manufacture. 

Many  of  the  specimens  of  powder  are  prepared  from  commercial 
metallic  zinc,  and  therefore  contain  the  impurities  of  that  metal. 
Among  the  latter  is  arsenic,  so  that  the  presence  of  arsenic  compounds 
in  inferior  cement  powders  is  by  no  means  impossible,  which  may  pos- 
sibly explain  in  some  cases  the  death  of  non-exposed  pulps  in  teeth 
which  have  been  filled  with  zinc  phosphate  ;  but  as  recent  chemical  in- 
vestigation has  shown  that  the  arsenic  when  present  in  cement  powders 
is  in  the  form  of  an  insoluble  zincarsenito,  the  danger  of  arsenical  irrita- 
tion of  the  pulp  from  tliat  source  would  seem  to  be  a  remote  one. 

A  common  source  of  the  glacial  phosphoric  (metaphosphoric)  acid  of 
commerce  is  from  sodium  phosphate,  variable  quantities  of  which  are 
retained  in  the  acid  solution  as  acid  sodium  phosphate  (dihydrogen 
sodium  phosphate).  This  substance  is  soluble  in  water,  and  must  there- 
fore greatly  increase  the  solubility  of  any  cement  containing  it. 

To  properly  make  pure  specimens  of  zinc  oxid  and  phosphoric  acid 
is  a  comparatively  expensive  operation — which  will  serve  to  explain  the 
seemingly  high  cost  of  fine  specimens  of  cement,  and  incidentally  serve 
as  a  warning  against  the  indiscriminate  use  of  cheap  cements. 

Makixg  the  Powder. — A  quantity  of  pure  zinc  oxid  is  luted  in  a 


BASIC  ZINC  CEMENTS.  337 

sand  crucible  and  kept  at  the  highest  forge-heat  for  hours.  AThen  cool 
the  crucible  is  broken  away  and  the  vitreous  mass  of  yellowish  zinc  oxid 
is  reduced  to  a  powder  which  will  pass  through  a  fine  bolting  cloth. 
This  powder  is  placed  in  tightly  stoppered  bottles,  for  if  exposed  to  the 
air  it  absorbs  carbon  dioxid  and  a  portion  of  it  is  converted  into  the 
hvdrated  carbonate  of  zinc.  This  change  may  be  noted  in  old  powders 
by  the  effervescence  due  to  the  disengagement  of  carbonic  oxid  when 
phosphoric  acid  is  added  to  them.  Numerous  substances  have  been 
added  to  the  basal  powder  with  the  object  of  lessening  the  disintegra- 
tion, I.  €.  chemical  solution,  when  used  as  a  dental  cement.  Usually 
these  additions  are  the  oxids  of  other  metals.  The  oxid  of  magnesium 
added  to  the  powders  causes  the  cement  to  set  more  rapidly  ;  the  oxid  of 
aluminum  increases  the  rapidity  of  setting  and  makes  a  finer-grained 
cement,  the  central  texture  of  which  is,  however,  inferior.  Cements  of 
zinc  oxid  and  phosphoric  acid  alone  are  apparently  less  soluble  in  lactic 
acid  than  when  the  oxids  of  aluminum  and  magnesium  are  added. 

Various  other  substances  have  been  added  which  do  not  enter  into 
chemical  combination  with  the  phosphoric  acid,  in  the  hope  of  confer- 
ring greater  durability  on  the  cement,  but  as  yet  but  few  of  them  have 
been  shoAvn  to  possess  any  value. 

The  Fluid. — Phosphoric  acid  in  its  pure  state  is  formed  by  hydrating 
phosphorus  pentoxid  : 

PA  +  3H20=2H3PO,. 

Much  of  the  phosphoric  acid  used  for  cements  is  made  by  hydrating 
the  glacial  (metaphosphoric)  acid,  HPO3.  The  acid  dissolves  readily 
in  water,  being  deliquescent  when  pure.  Difficulty  of  solution  is- 
therefore  an  indication  of  impurity  of  the  glacial  acid.  It  requires  a 
definite  degree  of  heat  to  bring  about  the  chemical  hydration  of  the 
acid.  At  a  temperature  of  210°  F.  the  union  occurs,  which  is  attended 
by  the  evolution  of  heat,  the  glacial  acid  being  transformed  into  ortho- 
phosphoric  acid.  These  acids  are  all  hygroscopic.  They  will  even  ab- 
stract water  from  sulfuric  acid. 

Impurities. — The  commercial  glacial  acid  is  commonly,  or  as  a  rule, 
impure,  containing  variable  amounts  of  sodium  and  magnesium  phos- 
phates. These  salts,  particularly  the  dihydrogen  (acid)  sodium  phos- 
phate, are  permanently  soluble  in  the  phosphoric  acid,  and  therefore 
give  no  evidence  of  their  presence  by  the  formation  of  precipitates. 
They  are  also  soluble  in  water,  which  fact  has  a  direct  bearing  upon  the 
durability  of  cements  made  with  the  impure  acid. 

It  has  been  stated  by  writers  that  the  acids  of  cement  were  occasion- 
ally the  meta-  and  pyrophosphoric.     A  test  of  some  of  them  said  to  be 


338  PLASTIC  FILLING  MATERIALS. 

of  these  varieties  showed  none  of  them  to  give  the  reaction  of  the  pyro- 
acid  ;  a  few  giving  traces  of  the  mota-  acid. 

Precipitates  which  form  in  cement  flnids  are  probably  metallic  ])hos- 
phates.  The  instability  of  cement  fluids  is  notorious.  Aside  from  the 
known  or  probable  contaminations  which  they  may  contain  this  insta- 
bility is  to  be  regarded  as  a  distinctive  feature  of  phosphoric  acid. 

The  Cement. — To  make  the  cement,  successive  portions  of  the  oxid 
are  mechanically  incorporated  with  the  fluid  until  a  stiif  paste  results. 
In  five  minutes  a  ball  made  of  the  paste  glazes,  and  rebounds  when 
dropped  upon  a  hard  surface.  It  breaks  with  a  granular  surface ;  in 
fifteen  minutes  it  is  cut  with  some  difficulty.  If  the  cement  fluid  con- 
tain the  acid  sodium  phosphate,  an  acid  reaction  may  remain  for  hours 
or  days.  The  atmospheric  conditions  markedly  modify  the  properties. 
In  warm,  or  hot  and  moist  weather,  the  setting  is  more  rapid  and  it 
may  be  sudden.  In  cold  weather  it  is  delayed.  The  greater  the  dilu- 
tion (the  thinner  the  fluid),  the  more  rapid  the  setting. 

In  its  freshly  mixed  state  zinc  phosphate  is  adhesive,  losing  this 
property  in  a  great  degree  when  set,  if  surrounded  by  moisture.  It  has 
a  higher  rate  of  heat  conductivity  than  zinc  oxychlorid. 

Uses. — Its  legitimate  field  of  usefulness  is  in  situations  and  under 
conditions  where  its  advantageous  properties  may  be  utilized  and  its 
disadvantages  minimized.  One  of  the  principal  facts  to  be  borne  in 
mind  is  the  solubility  of  the  cement  in  lactic  acid,  M'hich  is  present 
almost  always  about  the  necks  of  the  teeth,  in  approxiraal  spaces,  and 
along  gingival  margins.  Its  clinical  use  is  therefore  attended  by  the 
greatest  measure  of  success  when  placed  at  a  distance  from  such  situa- 
tions— as,  for  example,  in  cavities  opening  upon  the  masticating  sur- 
faces of  teeth,  where  its  great  hardness  is  an  element  of  advantage. 
Good  specimens  have  been  known  to  last  for  periods  varying  from 
three  to  eight  years.  Dr.  Henry  Weston  has  cited  cases  where  ah  un- 
usually good  zinc  phosphate  filling  has  lasted  for  ten  years. 

As  a  filling  material  'per  se,  zinc  phosphate  has  but  limited  employ- 
ment except  for  the  teeth  of  children,  and  as  a  temporary  filling  in  the 
teeth  of  adults.  Times  and  occasions  will  suggest  themselves  to  every 
operator  where  gold,  amalgam,  and  gutta-percha  are  contraindicated  as 
filling  materials  ;  in  such  cases  zinc  phosphate  performs  a  useful  ser- 
vice. Its  great  field  of  usefulness — where,  indeed,  there  is  no  substi- 
tute for  it — is  in  the  filling  of  the  greater  portion  of  extensive  cavities, 
which  are  then  filled  and  sealed  with  gold  or  amalgam,  by  an  inlay,  or  it 
may  be  by  a  partial  crown.  It  is  invaluable,  and  in  most  cases  indispen- 
sable, as  the  retaining  medium  of  fixed  bridge  work  and  of  many  forms 
of  artificial  crowns. 

Prior  to  placing  the  zinc  phosphate  filling  in  a  cavity,  it  is  a  wise 


BASIC  ZINC  CEMENTS. 


339 


Fig.  316. 


Dropper. 


Fig.  317. 


Scoop. 


Fig.  .318. 


precaution  to  line  the  latter  witli  one  of  the  quick -drying  ethereal  var- 
nishes, to  protect  the  dentinal  walls  from  contact  with  acid  sodium 
phosphate  Avhich  may  be  present  in  the  cement.  In  some  cases  the 
placing  of  the  cement  in  proximity  to  a  non-exposed  pulp  is  productive 
of  marked  suffering.  Should  the  cavity 
be  very  deep  it  is  the  usual  practice  to 
place  a  softened  disk  of  gutta-percha 
over  the  wall  nearest  the  pulp.  The 
rubber  dam  should  always  be  adjusted 
before  the  insertion  of  a  phosphate  fill- 
ing, to  insure  dryness  not  only  during 
the  insertion,  but  during  the  period  of 
hardening,  at  least  fifteen  minutes. 

MixiXG  OF  Cement. — This  is  an 
operation  of  equal,  if  uot  greater,  im- 
portance than  any  other  in  the  manipu- 
lation of  zinc  phosphate.  Dr.  Henry 
Weston  has  demonstrated  how,  almost 
entirely,  the  mixing  of  cement  gov- 
erns its  stability.  Specimens  of  the 
same  powder  and  fluid  mixed  after  dif- 
ferent methods  gave  entirely  different 
results,  not  only  in  the  ajipearance  but 
also  in  the  hardness,  texture,  and  solu- 
bility. The  method  of  mixing  set  forth 
is  that  of  the  same  experimenter.  As- 
sumiug  for  illustration  that  an  approx- 
imal  cavity  is  to  receive  a  contour  filling, 
or  a  large  occlusal  cavity  is  to  be  filled, 
Fig.  3M 


^ip~ 


Glass  mixing  tablet,  with  rubber  feet. 

or  an  extensive  cavity  is  to  be  three- 
fourths  filled  with  cement : 

A  drop,  or,  where  a  large  mass  of 
cement  is  required,  two  drops  of  fluid  are  placed  upon  a  scrupulously 
clean  glass  (Fig.  315)  by  means  of  the  dropper  shown  in  Fig.  316,  and 


hiiiiii 


Spatula. 


340  PLASTIC  FILLING  MATERIALS. 

a  mass  of  powder,  in  great  a})j)areut  excess  of  that  required,  is  heaped 
at  a  distance  from  it,  taken  from  the  bottle  by  the  scoop  (Fig.  317).  A 
portion  of  the  powder  is  drawn  into  the  fluid  by  means  of  a  stout  spatula 
(Fig.  318),  and  stirred  with  a  rotary  movement  until  a  thin  paste  is 
made ;  another  portion  of  powder  is  then  added  and  is  slowly  and  thor- 
oughly incorporated ;  more  powder  is  added  until  the  mass  is  as  thick  as 
putty  and  difficult  to  smear  with  the  heavy  spatida;  the  mass  is  scraped 
together,  taken  from  the  spatula,  and  rolled  between  the  forefinger  and 
thumb,  which  have  been  well  scrubbed.  The  mass  is  now  kneaded, 
then  rolled  into  an  oblong  pellet. 

If  for  an  occlusal  cavity  a  piece  about  one-fourth  the  size  of  the  cavity 
is  set  in  the  deepest  portion  and  tapped  into  perfect  apposition  with  the 
cavity  walls  by  means  of  a  burnisher.  Other  pellets  are  added,  and  the 
process  is  repeated  until  the  cavity  is  exactly  full,  the  burnisher  form- 
ing the  surface  of  the  filling  and  outlining  clearly  every  margin  of  the 
cavity.  The  filling  should  remain  under  rubber  dam  for  at  least  fifteen 
minutes — longer  when  possible.  A  coating  of  ethereal  varnish,  a  solu- 
tion of  gutta-percha  in  chloroform,  or  melted  paraffin  as  suggested  by 
Dr.  Bonwill,  is  applied  to  the  surface  and  the  grinding  of  the  filling 
deferred  for  a  day  or  two.  Should  the  cavity  be  upon  an  approximal 
side  of  a  tooth,  a  matrix  is  to  be  employed ;  the  most  satisfactory  and 
quickly  adapted  instrument  for  this  purpose  is  one  of  the  composition 
silver  strips  used  for  carrying  polishing  powders  (Fig.  319).     A  strip 

Fig.  310. 


I'olisliing  strip, 

as  wide  as  the  length  of  the  tooth  is  to  have  one  end  rolled  upon  itself 
until  it  forms  a  cylinder  more  than  one-sixteenth  of  an  inch  thick  (Fig. 
320,  A).     The  strip  is  passed  into  the  next  interdental  space  and  drawn 

Fig.  320. 


through  until  the  cylinder  [A]  rests  firmly  upon  the  teeth;  the  free  end 
is  now  passed  through  the  space  into  which  the  cavity  opens ;  where  it 


BASIC  ZINC  CEMENTS. 


341 


rests  upon  the  lingual  surface  of  the  tooth  it  is  burnished  into  contact 
with  the  edges  of  the  cavity,  forming  walls  to  the  latter  (320,  B).  The 
cement  is  introduced  as  in  the  preceding  case,  and  Mhen  the  cavity  is 
full  the  free  end  of  the  strip  is  drawn  upon,  compressing  and  round- 
ing the  filling.  Should  the  cement  be  an  adhesive  specimen  or  mixed 
thinner  than  described,  the  surface  of  the  flexible  mat-  Fig.  321. 
rix  is  to  be  faintly  oiled  by  means  of  olive  oil. 

At  the  completion  of  the  operation  the  cement  should 
be  exactly  flush  with  the  margins  except  at  the  labial 
aspect,  and  the  surface  of  the  cement  should  have  such 
smoothness  that  polishing  is  not  necessary.  Cement 
fillings  are  polished  dry  with  the  finest  of  cuttlefish 
disks. 

The  process  of  filling  the  body  of  any  cavity  is  the 
same,  except  when  the  enamel  walls  are  thin  and  frail. 
In  the  latter  case,  where  space  permits,  it  is  preferable 
to  line  the  walls  with  the  oxyehlorid  of  zinc, over  which 
the  phosphate  is  placed.  Before  inserting  a  veneer  fill- 
ing of  gold  or  amalgam,  each  cavity  margin  must  be 
scraped  free  from  cement. 

When  orthodontia  appliances  such  as  rings  or  caps, 
or  prosthetic  appliances,  crowns  and  bridges,  are  to  be 
set  it  is  preferable  to  use  a  cement  prepared  for  that 
purpose,  although  it  is  the  general  practice  to  use  the 
cement  to  which  the  operator  is  accustomed,  mixing  it 
thinner  than  for  filling  purposes.  Wherever  possible, 
it  is  advisable  to  operate  under  rubber  dam,  even  while 
setting  orthodontia  appliances. 

The  tooth  is  cleansed  with  chloroform — as,  for  ex- 
ample, when  a  ring  or  cap  is  set^ — to  remove  fatty  mat- 
ters, and  a  layer  of  shellac  varnish  applied,  which  is 
then  dried  by  the  air  blast  (chip  blower).  Cement 
paste  is  formed,  of  such  consistence  tliat  it  \\\\\  floAV 
readily  and  yet  not  be  watery ;  the  inside  of  the  band 
or  cap  is  filled  with  cement  by  means  of  an  appropriate 
spatula  (Fig.  321) ;  a  layer  of  cement  is  placed  on  the 
tooth  where  it  is  to  be  embraced  by  the  band,  which  is 
then  pressed  into  position  and  is  to  remain  without 
disturbance  until  it  is  hard.  The  application  of  bands 
or  ligatures  should  be  deferred  until  the  following  day. 
As  soon  as  the  cement  is  hard  the  surplus  is  cut  away 
and  the  dam  removed.  Pointed  spatula. 


342  PLASTIC  FILLING  MATEIUALS. 

Temporary  Stopping. 

Preparations  of  this  name  are  coin])ounds  of  2:utta-percha  with 
various  substances  added  to  lessen  the  temperature  of  softening. 

As  procured  from  the  manufacturer  tliey  are  of  two  varieties,  the 
adhesive  and  the  non-adhesive — or,  to  be  more  precise,  the  less  adhesive. 
The  former  preparations,  the  adhesive,  are  usually  made  of  gutta-j^ercha 
(generally  the  pink  base  plate).  Burgundy  pitch,  white  wax,  and  chalk 
or  zinc  oxid.  In  the  non-adhesive  varieties  the  Burgundy  pitch  is  omitted. 
The  latter  varieties  are  usually  made  of  a  pink  color,  to  furnish  a  safe- 
guard against  mistaking  a  filling  of  temporary  stopping  for  one  of  gutta- 
percha. 

As  the  name  implies,  they  are  designed  for  temporary  use,  retaining 
dressings  in  teeth,  to  maintain  space  between  teeth  which  have  been 
wedged  apart,  until  the  attendant  pericementitis  subsides  ;  to  press  away 
gum  tissue  overhanging  the  margins  of  a  cavity ;  to  fill  excavated  cav- 
ities for  a  few  days. 

Unlike  gutta-percha,  most  of  these  preparations  cannot  be  permitted 
to  remain  for  a  prolonged  period  ;  they  usually  become  offensive,  par- 
ticularly so  when  the  hygiene  of  the  mouth  does  not  receive  proper 
attention.  To  maintain  space  and  press  away  gum  tissue  they  are  used 
as  gutta-percha ;  their  lower  heat  of  softening  permits  their  application 
close  to  the  pulp  of  a  tooth  without  the  painful  response  associated  with 
placing  hot  gutta-percha  in  the  same  position.  A  prominent  use  of  the 
material  is  the  sealing  of  arsenical  applications  in  teeth. 

As  with  any  other  material,  it  is  necessary,  in  order  to  have  the 
minimum  of  pain,  to  make  the  application  and  manipulate  the  stopping 
so  that  no  pressure  shall  be  exerted  upon  the  pulp.  Temporary  stop- 
ping is  inferior  to  zinc  phosphate  for  this  purpose,  as  the  latter  may  be 
flowed  into  a  cavity  and  over  an  arsenical  application  without  causing 
the  slightest  pressure. 

Should  the  cavity  of  decay  extend  to  or  beyond  the  gum,  a  small 
conical  piece  of  the  temporary  stopping  should  be  softened  and  packed 
carefully  against  the  cervical  margin  and  gum,  to  act  as  a  guard  to  the 
latter  against  contact  with  the  virulent  irritant  arsenic  trioxid.  The 
arsenical  paste  on  a  minute  pledget  of  cotton  is  laid  upon  the  exposed 
pulp — if  the  latter  be  hypersensitive,  beside  it — and  the  remainder  of 
the  cavity  and  interdental  space  are  filled  with  one  very  soft  piece  of 
temporary  stopping. 

Temporary  stopping,  in  cones,  has  been  used  as  a  canal  filling  (see 
Cliapter  XA^II.)  and  as  a  filling  for  the  bulbous  portion  of  pulp 
chambers. 

Another  important  use  of  the  material  is  the  sealing  of  the  occlusal 
cavities  of  teeth  which  are  under  treatment  for  septic  pericementitis. 


OXYSULFATE  OF  ZINC.  343 

Plugs  of  softened  temporary  stopping  have  been  used  for  the  arrest 
of  alveolar  hemorrhage  ;  also  for  the  temporary  setting  of  artificial 
crowns. 

Lining  Varnishes. 

These  are  solutions  of  various  gums  and  resins  in  alcohol,  chloro- 
form, and  ether,  which  are  employed  to  furnish  a  non-conducting  and 
impermeable  film  to  cover  the  dentinal  w'alls  of  excavated  cavities. 

The  first,  sandarac  varnish,  is  a  thin  solution  of  sandarac  in  alcohol. 

The  second,  a  solution  of  virgin  rubber  in  chloroform. 

The  third  a  solution  of  hard  Canada  balsam,  copal,  or  damar  in 
ether. 

Another  is  the  preparation  known  as  I'ristaline,  a  solution  of  trinitro- 
cellulose  in  anhydrous  amyl  acetate. 

Before  lining  a  cavity  with  zinc  oxychlorid,  a  film  of  one  of  these 
varnishes,  the  quick-drying  ones  preferred,  is  applied,  and  when  this  is 
dry  the  cement  may  be  inserted  without  causing  pain.  Varnishes  have 
been  used  to  furnish  an  adhesive  surface  upon  which  to  pack  gutta- 
percha fillings.  It  is  always  advisable  to  varnish  the  walls  of  a  cavity 
which  is  to  receive  a  filling  of  zinc  phosphate,  to  prevent  the  action  of 
any  free  acid  or  acid  salt  upon  the  dentinal  walls. 

Some  of  these  varnishes  are  admirable  non-conductors,  and  serve 
in  that  capacity  under  gold  or  amalgam  fillings  in  a  most  satisfactory 
manner. 

They  may  be  used  to  prevent  the  tooth  discoloration  due  to  the  pres- 
ence of  amalgam,  particularly  of  copper  amalgam. 

OxYSULFATE    OF     ZiNC. 

What  is  known  as  the  oxysulfate  of  zinc  in  dental  parlance  is 
merely  a  thin  zinc  oxychlorid  containing  zinc  sulfate.  A  true  zinc 
oxysulfate  is  made  by  mixing  a  saturated  solution  of  zinc  sulfate  wdth 
uncalcined  zinc  oxid.  It  forms  a  white  paste  which  sets  quickly  and 
attains  about  the  hardness  of  an  inferior  plaster-of-Paris. 

It  is  bland  and  unirritating  to  exposed  pulps  ;  is  a  non-conductor ; 
is  faintly  and  persistently  astringent.^ 

Its  principal  use  is  as  a  pulp  capping  or  protective.  A  thin  paste  is 
made,  in  which  a  disk  of  paper  is  dipped,  then  quickly  and  accurately 
laid  upon  the  area  of  exposure.  When  hard  (in  a  few  seconds)  a  drop 
of  fresh  thin  paste  is  flowed  over  the  capping.  The  cavity  may  then  be 
lined  with  zinc  phosphate. 

As  a  pulp  protector  from  thermal  shock  it  is  applied  in  a  thin  layer, 
and  over  it  a  lining  of  zinc  phosphate  is  packed. 

^  J.  Foster  Fiagg. 


CHAPTER    XIV. 
COMBINATION!   FILLINGS. 
By  Dwight  M.  Clapp,  D.  M.  D. 


The  use  of  more  than  one  material  for  filling  a  single  cavity  was 
suggested  by  the  observation  of  the  condition  of  fillings  composed  of 
but  one  material  and  noting  the  effects  of  time  and  use  thereon. 

If  a  large  number  of  amalgam  fillings  in  crown  cavities  are  exam- 
ined, many  will  be  found  to  have  imperfect  edges.  One  cause  of  this 
imperfection  is,  undoubtedly,  the  brittle  character  of  amalgam,  in  con- 
sequence of  which  the  edges  have  become  broken.  In  other  words, 
amalgam  as  a  filling  material  lacks  edge  strength.  Its  dark,  sometimes 
almost  black,  color  also  renders  it  very  objectionable,  especially  if  used 
in  conspicuous  positions. 

If  the  same  number  of  gold  fillings  in  occlusal  cavities  are  examined, 
the  edges  will  be  found  in  better  conditi(in  than  was  the  case  with  the 
amalgam.  One  reason  for  this  is,  undoubtedly,  because  gold  is  not 
brittle,  but  possesses  sufficient  edge  strength  to  withstand  the  force 
of  mastication.  Its  color  is  also  less  unsightly  than  that  of  amalgam. 
For  occlusal  cavities,  therefore,  gold  is  regarded  as  the  better  filling 
material. 

If  a  series  of  occluso-approximal  cavities  filled  with  gold  be  studied, 
it  will  be  found  that  the  teeth  are  in  much  better  condition  on  the  oc- 
clusal surface  than  at  the  cervical  borders  of  the  fillings.  Compare  gold 
fillings  with  a  series  of  amalgam  fillings  in  the  same  class  of  cavities, 
and  the  condition  of  the  teeth  will  be  reversed  :  at  least  a  much  larger 
percentage  of  the  teeth  will  be  found  in  good  condition  around  the  ap- 
proximal  portion  of  the  fillings  than  was  the  case  with  the  gold.  Hence, 
the  deduction  is  inevitable  that,  of  these  two  materials,  amalgam  is  the 
better  to  fill  the  cervical  jiortion  of  approximal  cavities. 

!  The  term  "combination  "  is  adopted  for  the  various  fillings  here  described,  in  which 
more  than  one  material  is  used,  because  it  seems  to  be  the  most  comprehensive.  The 
putting  together  of  different  materials  in  filling  teeth  makes  in  no  sense  a  chemical  combi- 
nation, in  which  "any  part  of  the  compound  is  the  same  as  any  other  part  of  it." 
Strictly  speaking,  the  fillings  are  more  "mixtures"  than  "combinations."  According  to 
the  best  authorities,  however,  the  meaning  given  to  combination  makes  its  use  here  quite 
admissible. 

345 


346  COMBINATION  FILLINGS. 

Zinc  phos])hato  cement  has  many  admirable  qualities  and  is  one  of 
the  most  valuable  filling  materials  known.  It  is  easily  worked,  its  color 
is  good,  its  adhesiveness  serves  to  bind  tooth  and  filling  together  as  the 
stonemason's  cement  unites  the  blocks  of  granite  that  he  piles  one  on 
the  other  into  one  solid  piece  of  masonry.  As  a  tooth-saver  it  has  no 
equal ;  but  its  one  great  defect,  its  solubility  in  the  fluids  of  the  mouth, 
restricts,  in  a  great  degree,  its   usefulness  when  exposed  to  these  fluids. 

From  this  it  will  be  easily  understood  why  it  is  often  desirable  to 
combine  in  one  filling  two  or  more  difi'erent  materials  ;  and  it  may  be 
said  with  truth  that  the  operator  who  selects  his  filling  materials  with 
the  best  judgment,  and  combines  and  uses  them  with  the  most  skill, 
will  save  the  greatest  number  of  teeth.  There  would  be  just  as  much 
common  sense  and  scientific  reason  for  an  electrician  to  make  a  dynamo 
entirely  of  copper,  or  a  watchmaker  to  use  nothing  but  gold  in  making 
a  watch,  as  for  a  dentist  to  fill  many  of  the  cavities  that  come  to  him 
with  but  one  material. 

It  is  an  error  to  think  that  combination  fillings  are  resorted  to- 
because  more  easily  made  than  fillings  of  but  one  material,  or  that  it 
indicates  a  lack  of  skill  on  the  part  of  the  operator  who  makes  and 
recommends  them.  On  the  contrary,  it  is  often  much  more  difBcult  to 
make  a  suitable  comliination  filling  than  one  of  any  single  material ;  and 
the  student  will  find  that  combination  work  will  give  ample  opportunity 
for  the  employment  of  all  the  skill  and  ingenuity  he  may  possess. 

Every  operation  must  be  made  with  the  greatest  amount  of  care  and 
attention  to  minute  details,  or  the  object  sought  will  be  unattained,  and 
the  result  be  an  inferior  piece  of  work  which  will  sooner  or  later  cause 
grief  to  the  patient  and  chagrin  to  the  operator. 

It  is  impossible  to  describe  all  the  combination  fillings  that  have 
been  found  advantageous  and  useful,  therefore  only  some  of  the  most 
important  will  be  considered  in  detail.  The  list  is  limited  only  by  the 
perverse  manner  in  which  teeth  decay,  and  by  the  ingenuity  of  the  ope- 
rator to  devise  scientific  and  practical  combinations  to  meet  the  cases 
presenting. 

It  is  to  be  understood  in  every  instance  in  this  chapter  that  the  teeth 
are  in  proper  condition  to  be  filled  without  further  treatment.  If  pulp- 
less,  the  roots  are  supposed  to  have  been  put  in  a  healthy  condition  and 
filled.  In  cases  of  exposed,  or  nearly  exposed,  pulps,  they  are  supposed 
to  have  been  properly  protected,  and  the  teeth  ready  in  every  respect 
for  the  mechanical  operation  of  inserting  the  fillings. 

Cement  (Zinc  Phosphate)  and  Amalgam. 

In  Simple  Cavities. — This  combination  is  of  the  greatest  service  in 
saving  badly  decayed  teeth  that  otherwise  might  have  to  be  cut  off  and 


CEME]^T  AND  AMALGAM. 


347 


Fig.  322. 


Large  occlusal 
cavity. 


crowned,  or  perhaps  lost  altogether.  The  simplest  cases  where  it  may 
judiciously  be  employed  are  occlusal  cavities.  Many  such  cases  are 
seen  where  there  is  little  left  but  the  enamel,  which,  however,  is  thick 
around  the  orifice  of  the  cavity,  and,  if  properly  supported,  will  have 
sufficient  strength  to  withstand  the  ordinary  strain  of  mastication. 
Great  care  should  be  taken  to  remove  the  decay  from  every  part  of  the 
cavity,  being  sure  that  none  is  left  under  the  cusps  or  any  part  of  the 
overhanging  enamel. 

The  edges  of  the  cavity  must  be  carefully  trimmed,  so  that  the  filling 
can  be  finished  flush  with  the  external  surface,  in  order  not  to  leave  any 
overhanging  portion  of  amalgam  to  be  broken  off,  as  it  certainly  will  be 
if  so  left,  to  the  great  injury  of  the  filling. 

There  are  but  few  cases,  even  in  occlusal  cavities,  where  the  rubber 
dam  should  not  be  used,  at  least  for  the  final  excava- 
tion and  for  putting  in  the  filling ;  for  it  is  almost  im- 
possible to  be  sure  that  all  decay  has  been  removed 
from  a  cavity  unless  it  is  dry.  No  filling  should  be 
allowed  to  get  wet  before  it  is  all  in  place  if  it  can 
possibly  be  avoided.  It  is  much  better  to  err  by 
using  the  rubber  dam  too  often  than  not  often  enough. 
Fig.  322  shows  a  cavity  such  as  described. 

The  cavity  being  ready,  sufficient  amalgam  to  fill 
one-third  of  it  is  prepared.  Before  introducing  the  amalgam,  however^ 
the  cavity  is  filled  two-thirds  or  three-fourths  with  rather  soft  cement, 
into  which  pieces  of  the  prepared  amalgam  are  crowded,  forcing  the 
cement  into  every  portion  of  the  cavity.  The  cement 
which  has  oozed  out  around  the  edo-es  is  then  removed 
Avith  an  excavator,  and  the  operation  will  have  the  ap- 
pearance shown  in  Fig.  323.  The  filling  is  then  com- 
pleted in  the  same  manner  as  an  ordinary  filling  of 
amalgam  in  an  occlusal  cavity. 

The  advantages  of  this  kind  of  filling  are  many :  The 
bulk  of  it  is  of  cement,  which  does  not  change  its  shape 
perceptibly  and  is  the  best  of  materials  when  not  ex- 
posed to  the  fluids  of  the  mouth.  The  cement  firmly 
removed;  then  unites  the  tooth  to  the  filling,  thus  making  a  support  to 
amait'amT^  the  frail  walls  as  well  as  a  stopping  to  the  cavity.  The 
amount  of  metal  is  reduced  to  just  enough  for  a  cover- 
ing of  sufficient  strength  to  guard  the  cement,  and  the  tooth  will  not  be 
discolored  by  the  amalgam,  as  is  often  the  case  in  teeth  of  not  very 
dense  structure,  and  especially  in  the  mouths  of  young  patients,  when 
not  thus  protected. 

The  combination  of  cement  and  amalgam,  as  described  above  for 


Section  showing 
amalgam  and 
cement.  (Sur- 
plus cement 
must    now    be 


348  COMBINATION  FILLINGS. 

occlusal  cavities,  may  be  used  in  the  same  manner  in  simple  approximal 
cavities  in  the  molars  and  bicus])ids,  and  even  in  the  six  front  teeth, 
when  the  cavities  arc  so  situated  that  the  amalgam  docs  not  show. 
AVlien  used  in  the  front  teeth  the  cement  should  be  allowed  to  remain 
very  near  to  the  edges  of  the  cavity.  The  amalgam  need  not  be 
more   in    amount   at   this   point   than   the  thickness   of  an    ordinary 

Fig.  324. 


Cement  and  amalgam  fiUing  in  an  incisor.    The  surplus  cement  has  been  removed  and  the  fill- 
ing is  now  ready  for  the  finishing  portions  of  amalgam  :  a,  enamel ;  b,  cement ;  c,  amalgam. 

visiting  card  (see  Fig.  324).  For  the  front  teeth  very  light  colored 
amalgam  should  be  selected,  as  color  is  of  more  importance  than 
strength. 

In  the  temporary  molars  this  combination  can  be  used,  frequently, 
with  the  greatest  satisfaction,  especially  in  those  shallow  approximal 
cavities  where  but  little  undercut  can  be  obtained  without  exposing  the 
pulp.  The  cement  should  be  used  quite  thin,  and  the  amalgam  worked 
into  it  with  a  burnisher,  or  rounded  instrument,  forcing  the  cement  to 
a  feather  edge  at  the  margins  of  the  cavity.  In  cases  of  this  kind  resto- 
ration of  contour  should  not  be  attempted,  as  the  force  of  mastication 
might  serve  to  fracture  the  cement  and  dislodge  the  filling.  In  this 
manner  many  troublesome  and  difficult  cavities  can  be  successfully 
treated,  and  teeth  made  to  last  their  allotted  time  that  would  otherwise 
be  prematurely  lost. 

In  Compound.  Cavities. — A  more  extended  description  will  be 
necessary  for  the  treatment  of  compound  cavities  in  the  bicuspids  and 
molars,  especially  where  it  is  desirable  to*  restore  contour.  In  these 
cases  a  matrix  is  often  a  necessity.  There  are  many  matrices  that  may 
be  used  successfully,  but,  as  they  are  described  in  other  parts  of  this 
work,  only  one  need  be  mentioned  here.  This  is  selected  on  account  of 
being  almost  universal  in  its  ap])lication.  It  can  be  made  from  any 
metal  not  acted  on  by  the  mercury  contained  in  amalgam.  German 
silver  is  inexpensive  and  seems  to  meet  every  requirement,  and  is, 
therefore,  recommended.  For  ordinary  use  it  should  be  from  No.  35  to 
No.  38  gauge.  If  stiff  it  should  be  annealed,  so  as  to  be  readily  bent  to 
the  form  of  the  tooth.     It  can  be  easily  polished  so  as  to  reflect  light 


CEMENT  AND  AMALGAM. 


349 


into  the  cavity,  by  drawing  a  narrow  strip  of  it  between  two  pieces  of 
stationer's  rubber  (ink  erasers).  Place  one  piece  of  the  rubber  on  a 
table,  then  the  strip  of  metal  held  with  pliers  in  one  hand  is  placed  on 
the  cake  of  rubber,  while  with  the  other  hand  another  piece  of  rubber 
is  held  firndy  down  on  the  metal,  which  is  drawn  between  the  two  until 
sufficiently  bright. 

For  ordinary  cases,  a  piece  is  cut  from  the  German  silver,  as  shown 
in  Fig.  325,  A,  wide  enough  to  extend  from  the  top  of  the  tooth  to  a 
little  beyond  the  cervical  wall  of  the  cavity,  and  long  enough  to  a  little 
more  than  cover  the  cavity  laterally  when  tied  in  place.  Sometimes  it 
is  necessary  to  make  the  matrix  with  a  lip  to  extend  under  the  gum,  as 
shown  in  Fig.  325,  B,  or  in  some  other  irregular  form,  so  that  it  can  be 


Fig.  325. 


A,  Matrix  and  ligature;  B,  lipped  matrix. 

made  to  properly  fit  the  cavity.  Special  cases  may  require  a  very  wide 
or  a  very  narrow  one.  The  operator's  ingenuity  must  devise  the  right 
shape. 

For  tying  the  matrix  to  the  tooth,  coarse,  well-waxed  floss  silk  is  the 
best.  It  is  passed  through  the  holes  punched  in  the  metal,  as  shown 
in  Fig.  325,  A  and  B.  When  these  holes  are  made,  the  edges  must  be 
finished  smooth,  or  the  silk  will  be  cut  when  drawn  tightly  around  the 

tooth.     The  operator  must  use  tact  as  to 
Fig.  326.  how  and  where    to    make    his    knots    in 

tying  on  the  matrix.  Usually,  a  good 
way  is  to  place  one  end  of  the  ligature,  a, 
between  the  teeth,  then  to  make  a  sur- 
geon's knot,  as  shown  in  Fig.  326.  The 
other  end  of  the  ligature,  b,  is  then  forced 
between  the  teeth,  and  the  knot  tightened. 
This  will  bring  the  knot  between  the 
teeth  and  opposite  the  matrix  and  will  hold  the  latter  until  it  can  be 
shaped  and  bent  into  place  with  a  burnisher  or  other  suitable  instru- 
ment. The  knot  is  again  tightened,  and  the  two  ends  of  the  ligature 
carried  to  the  back  of  the  matrix  and  a  similar  knot  tied  there.  The 
second  knot,  when  drawn  tightly  against  the  back  of  the  matrix,  forces 
it  closely  up  to  the  cervical  border  of  the  cavity,  and  makes  a  firm 
resistance  when  the  filling  is  being  condensed.     The  silk  is  then  wound 


Manner  of  ligating  the  matrix. 


350  COMBINATION  FILLINGS. 

round  and  round  the  tooth  and  matrix  until  it  nearly  covers  both,  or  at 
least  sufficiently  to  insure  its  remainino;  in  ])laec  during  the  operation. 
A  knot  may  be  tied  each  time  the  silk  is  wound  around  the  tooth,  or 
not,  as  appears  to  be  necessary.  Sometimes,  Avhen  the  sides  of  the 
tooth  are  sloping,  the  ligature  has  a  tendency  to  slip  oif.  This  can 
usually  be  overcome  by  turning  ba(!k,  with  tweezers,  the  two  upper 
corners,  as  shown  in  Fig.  331.  To  saturate  the  ligature  wdth  sandarac 
or  other  sticky  varnish  will  sometimes  be  sufficient  to  prevent  the  same 
tendency. 

Fig.  327  illustrates  a  simple  and  delicate,  but  very  powerful,  little 

Pj^  gf,y  slip  matrix  which  is  of  great  efficiency 

in  the  treatment  of  occluso-approximal 

cavities.  They  were  conceived  originally 

for  the  plastics,  in  which  case  they  are 

left  in  place  over  night  (the  plastics  thus 

setting  under  pressure),  slipping  out  easily  the  next  day  away  from  the 

then  hardened  and  perfectly  contoured  surface  of  the  filling. 

"  They  are  most  easily  made,  even  for  each  case  (though  in  practice 
this  is  not  necessary,  as  they  may  be  employed  over  and  over  again), 
as  follows:  Suitable-shaped  pieces,  of  a  size  to  a  little  more  than  over- 
lap the  cavity  margins,  are  cut  from  thin  .  .  .  steel,  ...  all  corners 
and  burred  edges  smoothly  finished  ;  a  tiny  hole  is  punched  close  to 
the  middle  of  both  the  buccal  and  lingual  edges,  and  it  is  then  laid 
upon  a  piece  of  lead  and  swaged  (not  merely  bent,  be  it  remarked)  into 
perfect  concavity,  greater  or  less  as  the  individual  case  shall  require, 
by  tapping  with  a  hammer  a  convex  rod  of  hardened  steel  laid  upon  it ; 
my  own  instrument  being  a  round-headed  picture  nail,  case-hardened, 
polished,  and  with  twisted  wire  attached  at  right  angles  to  a  handle. 
Any  amount  or  shape  of  concavity  required  for  each  case  can  thus  be 
produced  in  a  moment,  either  newly  from  blanks  kept  ready  or  changes 
made  in  those  used  for  other  cases  to  fit  the  one  in  hand,  about  a 
dozen  of  different  sizes  and  degrees  of  convexity  being  sufficient  to 
select  from,  with  little  or  no  changes  for  all  ordinary  cases.  The 
tapping  having  re-stiffened  the  steel  somewhat,  taken  in  connection 
with  the  impingement  of  the  convex  face  against  the  approximal 
surface  of  the  adjoining  tooth,  gives  firmness  and  strength  to  these 
delicate  little  strips  and  a  perfect  hugging  fit  to  the  surfaces  of  the 
tooth  being  filled,  especially  at  its  cervical  margin,  that  is  most 
satisfactory."  ^ 

When  the  cavity  involves  a  large  portion  of  the  crown,  or  the  mesial 
and  distal  surfaces,  the  matrix  should  be  long  enough  to  almost  encircle 

^  Dental  Cosmos,  June   1898,  vol.  xl.  No.  6,  p.  452. 


CEMENT  AND  AMALGAM. 


351 


Fig,  329. 


Matrix  with  marginal  slits. 


the  tooth,  the  ends  nearly  joining  against  the  sound  remaining  wall  (see 
Fig.  328).  In  such  cases  it  may  be  desirable  to  slit  it  one  or  more 
times,  in  order  that  it  may  be  made  to  take  the  form  of 
the  tooth  more  easily  (Fig.  329). 

After  the  tying  is  completed,  a  suitably  shaped  bur- 
nisher is  used  to  form  the  matrix,  by  pressing  it  outward, 
to  a  proper  contour. 

One  of  the  desirable  features  of  the  matrix  here  de- 
scribed is  the  ease  with  which  it  is  made  to  giye  just  the 
right  shape  and  contour  to  the  filling.  When  used  for 
gold  fillings  it  yields  enough  so  that  with  a  little  care  in 
packing  the  gold  can  be  forced  beyond  the  margin  of  the  cayity  suf- 
ficiently to  insure  a  flush  filling  when  burnished,  after  remoying  the 
matrix. 

A  matrix  put  on  as  described  will  haye  sufficient  resistance  for  a  gold 
filling ;  for  amalgam,  cement,  or  gutta-percha  it 
may  not  be  necessary  to  tie  it  quite  so  securely. 

For  compound  fillings  of  cement  and  amalgam 
two  methods,  A  and  B,  are  here  giyen. 

A.  Those  cavities  whicli,  although  large  and 
inyolving  much  of  the  tooth,  may  haye  but  small  or  comparatiyely  small 
openings,  especially  if  a  matrix  be  used — and  there  are  but  few  cases 
where  the  matrix  is  not  advisable.  If,  after  putting  on  the  matrix,  in 
this  class  of  cavities,  cement  is  introduced,  and  pieces  of  amalgam 
thrust  into  it,  the  cement  will  most  likely  be  carried  to  the  margin  of 
the  cavity  at  the  cervical  wall,  and  it  will  be  found,  after  removing  the 
matrix  and  finishing  the  filling,  that  a  part  of  the  external  portion  is 
of  cement,  and  not  being  protected  by  the  amalgam,  Avould  be  washed  out. 
To  avoid  this,  a  portion  of  the  filling  is  made  before  the 
matrix  is  put  o)t.  Cement  is  put  in,  followed  immediately 
by  the  amalgam  as  described  for  "  occlusal  cavities  " 
with  the  added  complication  of  the  missing  approximal 
wall.  After  sufficient  amalgam  has  been  put  into  the 
cement  the  portion  of  the  latter  which  may  have  oozed 
out  must  be  carefully  cut  away,  so  as  to  expose  the  entire 
outer  edge  of  the  cavity,  includino-  the  cervical  wall  fsee  ^^™^"*  \"""^  -'^"'^ 

°  "  '  ^  ^~  amalgam. 

Fig.  330). 

After  this  has  been  done,  the  matrix  may  be  tied  on  and  the  filling 
completed  as  though  it  were  but  a  simple  cavity.  Sometimes  it  is  well 
to  leave  the  matrix  in  place  until  the  amalgam  is  fully  set.  If  this  be 
done,  care  must  be  taken  that  no  sharp  edge  or  corner  of  it  be  left  to 
wound  the  tongue  or  cheek. 


352 


COMBINATION  FILLINGS. 


Vu;.  ?>?.\. 


a,  Matrix;  ^,  amalgam  packed 
against  the  matrix  ;  c,  por- 
tion of  cavity  to  be  nearly 
filled  with  cement  and  fin- 
ished with  amalgam. 


Fig. 


B.  Cavities  with  large  open'mgH.  The  rubber  clam  and  matrix 
having  been  adjusted,  enough  amalgam  is  packed 
against  the  matrix  to  form  a  shell  of  sufficient 
strength  to  make  the  approximal  wall  of  the 
filling  (see  Fig.  331). 

This  will  leave  a  hu'ge  portion  of  the  cavity 
unfilled  as  sliown  in  tlie  figure  ;  in  this  space  is 
placed  cement,  which  is  gently  worked  into  the 
soft  amalgam,  but  with  care  not  to  carry  it 
through  to  the  matrix.  Before  the  cement  be- 
comes  hard  more  amalgam  is  put  in,  the  sur- 
plus cement  is  removed,  and  the  whole  finished 
to  look  like  an  entire  amalgam  filling,  while  in  reality  it  is  only  a  shell 
of  amalgam,  perfectly  fitting  the  outside  of  the  cavity,  cemented  into 
place.  If  the  walls  of  the  tooth  are  frail,  the  cement  Avill  serve  to 
greatly  strengthen  them.  If,  as  some  claim,  large  metal  fillings  alter 
sufficiently  under  changes  of  temperature  to  fracture  frail  walls,  the 
danger  is  by  this  method  reduced  to  a  minimum,  as  the  amount  of  metal 
is  only  just  sufficient  to  give  requisite  strength. 

There  is  another  class  of  cavities  which  may  be  described  in  this 
connection,  presenting  great  difficulties  in  themselves, 
yet,  with  this  simple  matrix,  they  are  often  easily 
filled.  It  is  those  cases  where  decay  has  reached  the 
alveolar  border  approximally,  and  extended  on  either 
the  buccal  or  lingual  portion  of  the  tooth,  or  both,  in 
such  a  manner  that  the  dam  cannot  be  made  to  stay 
beyond  the  cervical  border  of  the  cavity.  If  a  liga- 
ture is  used,  it  will  draw  into  the  lateral  grooves  of 
decay  and  be  of  no  use  (Fig.  332). 

The  mode  of  treatment  is  as  already  described, 
with  the  exception  that  the  matrix  is  adjusted  before  the  rubber  is  put  on. 
After  the  matrix  is  in  place,  it  is  but  the  work  of  a  moment  to  put  a 
Palmer  clamp  on  to  the  tooth,  and  slip  the  rubber 
dam  over  clamp,  matrix,  and  tooth.  If  the  matrix 
has  been  carefully  fitted  there  will  be  no  trouble  in 
keeping  the  cavity  dry  long  enough  for  any  ordinary 
operation. 

There    are    certain   buccal    cavities,    also,    below 
which  it  is  difficult  to  retain  the   rubber  dam.     A 
very    narrow    matrix,    adjusted    with    ligature    and 
Matrix     and     clamp     ^l^n^P  (Fig-  333),  over  which  the  rubber  is  placed, 
adjusted,  ready  for     y^\\\  often  greatly  sim])lifv  the  operation.     Modifica- 

application    of    the       ^.^^^^    ^^     ^j^.^    ^^^^^^^^    ^'^^    ^^^^    ^^    ^p^^j.^^    ^^    ^^^ 


Alveolar  line  be- 
yond which  tlie  liga- 
ture cannot  be  made 
to  stav. 


Fig.  333. 


CEMENT  AND   GOLD.  353 

bicuspids,  and  sometimes  even  to  marginal  cavities  in  the  incisors  and 
canines,  with  good  results. 

Cement  and  Gold. 

This  combination  may  be  used,  with  but  slight  modification,  in  the 
same  manner  and  in  the  same  class  of  cases  that  have  been  mentioned 
for  the  use  of  amalgam  and  cement,  cases  under  B  excepted.  The 
cement  is  placed  in  the  cavity,  and,  while  soft,  pieces  of  some  of  the 
so-called  "  plastic  "  golds  are  put  into  it,  in  the  same  manner  as  has 
been  described  for  cement  and  amalgam  ;  the  surplus  cement  is  carefully 
cut  away,  and,  after  waiting  for  that  in  the  cavity  to  become 
so  hard  as  not  to  break  or  crumble  under  jiressure,  the  pieces  of  gold 
placed  in  the  soft  cement  are  thoroughly  condensed.  For  this  pur- 
pose, de  Trey's  "Solila"  Gold,  Steurer's  Plastic  Gold,  White's  Crystal 
Mat  Gold,  and  Watts'  Crystal  Gold  are  recommended.  The  filling 
can  then  be  completed  with  the  same  or  any  kind  of  cohesive  gold. 
Care  must  be  taken  to  place  a  sufficient  amount  of  the  plastic 
gold  into  the  cement  to  make,  when  condensed,  a  solid  foundation 
upon  which  to  build  the  rest  of  the  filling.  If  too  little  gold  has 
been  used,  it  will  '*  chop  up "  and  not  make  a  secure  union  with  the 
cement. 

In  some  large  cavities  it  may  be  found  more  convenient,  after  having 
filled  the  approximal  portion  with  the  cement  and  gold,  to  make  a  second 
mix  of  cement  for  the  rest  of  the  cavity,  into  which  the  gold  is  put  as 
before. 

In  some  special  cases  it  may  be  well  to  use  foil  in  this  manner,  but, 
as  a  rule,  the  plastic  golds  will  be  found  preferable. 

Too  much  stress  cannot  be  laid  on  the  desirability  of  this  method 
for  frail  teeth,  remembering  always  that  the  cement  is  the  strengthening 
and  supporting  medium.  The  mason  would  not  build  a  bridge  pier  of 
granite  alone,  or  a  house  of  bricks  without  mortar.  However  nicely 
the  blocks  of  granite  or  the  bricks  might  fit  each  other,  it  is  the  cement 
and  the  mortar  that  hold  them  together  as  in  one  piece. 

Es])ecial  attention  is  called  to  this  combination  of  gold  and  cement 
for  the  six  front  teeth.  In  the  teeth  of  young  patients  and  teeth 
of  low-grade  structure  there  are  often  found  large  cavities  which, 
if  filled  with  gold  alone,  will  in  a  few  years,  sometimes  months,  show 
discoloration  around  the  fillings.  Filled  as  above  described,  every 
vestige  of  decay  having  first  been  removed,  a  coml)ination  results  which 
is  the  ideal  preservative  filling  as  far  as  present  knowledge  and  facilities 
go.  Pulpless  front  teeth  that  are  much  decayed  can  be  improved  in 
appearance  and  greatly  strengthened   by  this  method.     Fig.  334  shows 

23 


354  COMBINATION  FILLINGS. 

a  cavity  in  a  central  incisor  tliat  can  be  filled  to  advantage  with  cement 
and  gold.     Fig.  335  shows  a  cavity  in  a  central 
Fig.  334.    Fig.  335.  incisor  with  the  jinlp  removed  and  but  little  of 

the  crown  remaining  hut  the  enamel.  The  greater 
part  of  tlie  cavity  has  been  filled  with  cement  into 
which  plastic  gold  has  been  put  and  condensed. 
The  filling  can  be  completed  with  any  cohesive 
gold. 

In  compound  cavities  in  molars  and  bicuspids, 
o, a,  Frail  enamel  walls-     lifter  the  cement  and  gold  have  been  put  in,  as 
b,  gold  surface  made  by      described  for  cement  and  amalgam  A,  and  the 

plastic  gold   condensed  ^    .  t       ^     i  j-,   /■  -j  i  i   ^  i        -i 

into  cement.  matrix  adjusted,  sojtjou  can  be  used  to  great  ad- 

vantage at  the  cervical  portion  of  the  cavities,  as 
elsewhere  described  for  using  soft  and  cohesive  golds. 

Amalgam  and  Gold. 

Gold  may  be  used  in  combination  with  amalgam — A,  by  allowing 
the  amalgam  to  become  hard  before  adding  the  gold  ;  B,  by  adding 
the  gold  while  the  amalgam  is  soft  and  finishing  the  filling  at  one  sitting. 

A.  AUo-wing-  the  amalg-am  to  harden  and  then  adding-  gold  at  a 
subsequent  sitting  will  usually  be  done  in  compound  cavities  in  bicus- 
pids and  molars,  for  the  purpose,  principally,  of  overcoming  the  dark 
appearance  of  the  amalgam.  For  instance,  a  filling  involving  the  occlu- 
sal and  mesial  surfaces  of  an  upper  first  molar  will,  in  many  mouths, 
show  more  or  less,  and,  if  of  amalgam,  be  dark  and  unsightly.  To 
avoid  this,  the  cavity  may  be  nearly  filled  with  amalgam,  lea^  ing  a 
portion  of  the  occlusal  surface  and  along  the  buccal  wall  (tliis  being  the 
part  of  the  filling  most  likely  to  show)  for  completion  with  gold  later. 

The  matrix  should  be  used  as  described  for  cement  and  amalgam 
fillings.  It  is  a  good  plan  to  leave  it  in  place,  when  convenient,  until 
the  amalgam  is  hard.  Before  adding  the  gold,  it  should  be  ascertained 
what  part  of  the  filling  will  show,  and  the  amalgam  trimmed  and  shaped 
so  that  the  gold  may  form  that  portion  of  the  filling  that  will  be  in 
sight.  Fig.  336  shows  a  compound  cavity  in  a  molar  partially  filled  with 
amalgam.  The  amalgam  has  been  left  until  hard  and  the  filling  is  now 
ready  to  be  finished  wdth  gold.  The  figure  also  shows  the  cement 
lining  under  the  amalgam. 

Suitable  retaining  places  must  be  made  in  the  amalgam  to  hold  the 
gold  in  position,  as  there  is  no  union  ])etween  the  two  in  this  case,  as 
there  is  when  gold  is  added  to  unset  amalgam.  The  gold  being  added 
makes  a  filling  much  superior  in  appearance  to  one  entirely  of  amalgam. 
The  gold  will  also  make  a  better  wearing  material  for  the  masticating 
surface,  having  better  edge  strength  than  the  amalgam,  and  therefore 


AMALGAM  AND  GOLD. 


355 


being  less  liable  to  be  broken  away  from  the  walls  of  the  cavity  by  the 
force  of  mastication,  as  spoken  of  elsewhere. 

Large  amalgam  fillings,  when  it  is  not  necessary  to  have  gold  added 
on  account  of  color,  will  be  greatly  improved  if  a  channel  is  made  with 
a  small  fissure  bur  between  the  amalgam  and  the  enamel,  and  this  care- 
fully filled  with  gold  (Fig.  337). 


Fig.  336. 


Occluso-approximal  cavity 
partly  filled  with  amal- 
gam ready  for  completion 
■with  gold:  a,  a,  amal- 
gam ;  b,  cement  lining. 


Fig.  337. 


Amalgam  and  cement  com- 
bination with  channel  cut 
in  occlusal  margin  for  re- 
ception of  gold  :  a,  amal- 
gam ;  b,  gold ;  c,  channel 
burred  out  ready  for  gold, 
shows  also  cement  lining. 


Fig.  338. 


Gold  and  amalgam  com- 
bination in  incisor:  a, 
amalgam ;  b,  gold. 


All  amalgam  fillings  when  gold  is  intended  to  be  added,  should  be 
put  in  with  soft  cement,  Avhenever  possible,  as  described  for  "  Cement 
and  Amalgam  "  fillings.  This  will  prevent  much  of  the  discoloration 
from  the  amalgam,  as  well  as  strengthen  the  teeth.  Many  front  teeth 
can  be  saved  and  made  to  look  well  by  filling  with  cement  and  amal- 
gam, as  before  described,  and,  after  the  amalgam  becomes  hard,  cutting 
away  that  portion  which  is  in  sight,  and  filling  with  gold  (Fig.  338). 

B.  Amalgam  and  gold  fillings,  the  gold  being  added  while  the 
anaalgam  is  soft.  These  fillings  will  be  indicated,  usually,  in  com- 
pound cavities  of  the  molars,  and  in  the  occluso-distal  and  sometimes- 
even  the  mesial  surfaces  of  the  bicuspids.  The  amalgam  will  occupy 
not  more  than  one-quarter  or  one-third  of  the  approximal  portion  of 
the  cavity,  but  sometimes  in  distal  cavities  of  molars  it  may  be  good 
judgment  to  have  as  much  as  three-fourths  of  that  portion  of  the  fill- 
ing, amalgam. 

No  operation  requires  greater  attention  to  detail,  or  more  neatness 
of  execution,  than  where  gold  is  used  in  conjunction  with  soft  amalgam. 
If  chips  of  the  unset  amalgam  are  left  around  the  matrix,  or  in  the  folds 
of  the  rubber,  or  in  any  place  where  they  may  be  caught  up  on  the  disk 
or  finishing  strip  and  rubbed  over  the  surface  of  the  gold  while  the 
filling  is  being  finished,  they  will  give  it  a  coating  of  mercury  and  injure 
the  appearance  of  the  work.  On  the  other  hand,  if  the  method  given  is 
followed  carefully,  no  detail  left  out  of  account,  no  slovenly  manipula- 
tion allowed  to  pass  for  neatness  and  tact  in  handling  the  materials,  the 


356  COMBINATION  FILLINGS. 

fillings  can  be  finished  as  soon  as  the  last  piece  of  gold  is  consolidated, 
without  the  least  danger  of  mercury  coating. 

In  preparing  the  cavity  for  a  filling  of  this  kind,  almost  no  tooth 
substance  has  to  be  cut  away  shnjjly  to  get  access  to  the  cavity,  to  prop- 
erly start  and  pack  the  filling,  as  is  often  necessary  if  an  entire  gold 
filling  is  to  be  made.  As  a  consequence,  much  valual)le  tooth  substance 
is  saved,  for,  so  long  as  the  decay  is  removed  and  frail  edge  walls  are 
cut  away,  the  amalgam  can  be  perfectly  packed,  no  matter  how  irregular 
the  surface  to  which  it  is  to  be  adapted.  Of  course,  the  excavation 
must  be  planned  so  that  a  filling  of  proper  contour  can  be  made,  and 
walls  cut  back  when  by  so  doing  future  decay  can  be  better  guarded 
against.  There  will  be  many  cases  encountered,  however,  where,  by 
this  method,  much  of  a  tooth  structure  can  be  left,  whereas  if  gold 
were  to  be  used  it  would  be  necessary  to  cut,  often  causing  severe 
pain,  in  order  that  the  part  might  be  properly  filled. 

For  the  jiurpose  of  describing  a  simple  combination  filling  of  this 
kind,  a  cavity  involving  the  occlusal  and  distal  surface  of  an  upper  sec- 
ond bicuspid  is  selected  as  an  example.  In  the  first  place,  sufficient 
space  must  be  secured  for  a  filling  of  the  right  contour,  and  to  allow 
for  passing  in  a  very  thin  strip  for  finishing  the  filling.  It  is  best  to 
secure  this  room  by  previous  wedging.  Space  having  been  secured,  the 
cavity  is  prepared  with  proper  undercuts,  and  the  walls  of  the  approxi- 
mal  part,  to  be  filled  with  gold,  made  at  as  nearly  a  right  angle  to  the 
matrix  as  possible.  This  is  in  order  to  facilitate  packing  the  gold,  it 
being  very  difficult  to  obtain  a  satisfactory  margin  if  the  walls  form  a 
very  acute  angle  with  the  matrix. 

A  matrix  so  adjusted  that  it  will  stand  the  pressure  of  putting  in 
the  filling  without  moving  is  an  absolute  necessity  for  this  combination. 
It  having  been  put  on  as  described  under  the  head  of  "  Cement  and 
Amalgam  "  fillings  (page  349),  enough  amalgam  is  carefully  packed  at 
the  cervical  wall  to  fill  one-fourth  or  one-third  of  that  portion  of  the 
cavity.  It  should  l)e  thoroughly  consolidated  by  using  properly  shaped 
instruments  and  sufficient  force  to  drive  it  into  every  part  of  the  cav- 
ity. It  is  a  good  plan  to  use  small  pellets  of  bibulous  paper,  forcing 
them  against  the  amalgam  with  medium-sized  instruments.  The  free 
mercury  which  rises  to  the  surface  should  be  carefully  removed.  It  is 
well  to  put  in  considerably  more  amalgam  than  is  to  be  left,  cutting 
out  the  surplus,  which  method  leaves  a  good  surface  upon  which  to 
begin  with  the  gold.  Before  the  gold  is  added,  however,  care  should 
be  taken  to  remove  every  chip  of  soft  amalgam  from  the  folds  of  the 
dam,  or  any  that  may  be  clinging  to  the  matrix,  or  in  any  position 
where  it  might  be  brought  in  contact  with  the  gold  when  finishing  the 
filling.     These  chips  will  remain  for  a  long  time  soft  enough  to  coat 


AMALGA3I  AND   GOLD. 


357 


the  gold  with  mercury  if  rubbed  against  it,  Fig.  339. 

therefore  they  must  be  disposed  of  or  an 
unsatisfactory  filling  will  be  the  result. 

The  proper  amount  of  amalgam  having 
been  packed    in  the   cavity,   medium-sized 
pieces  of  some  of  the  plastic  golds  before 
referred   to  are    immediately  added.     The 
instruments  used  first  on  the  gold  should  be  as  large  as 
cavity  will  accommodate,  as  they  will  break  it  up  less  and 
more  readily  carry  the  piece  where  it  is  wanted,  after  which 
each  piece  of  gold   should   be   thoroughly  condensed   with 
smaller  instruments. 

As  soon  as  the  gold  touches  the  amalgam  it  will  absorb 
mercury,  and  sometimes  several  pieces  of  the  gold  will  be 
entirelv  amalg-amated.  The  surface  of  the  fillino;  will  be- 
come  very  granular,  and  "  chop  up  "  to  a  certain  degree  as 
the  first  pieces  of  gold  are  used,  and  the  instrument  will 
cause  a  peculiar  squeaky  sound  as  it  is  pressed  against  the 
filling.  The  condensation  must  be  very  thorough  at  this 
point  of  the  work,  or  the  filling  will  be  porous  and  the  union 
between  the  amalgam  and  gold  unsatisfactory.  If  the  work 
is  thoroughly  done,  however,  the  filling  will  be  just  as  strong 
at  this  point  as  any  other.  As  piece  after  piece  of  the  plastic 
gold  is  added,  the  mercury  will  soon  cease  to  penetrate  it, 
and  the  surface  become  entirely  gold.  As  soon  as  this  stage 
is  reached,  and  no  more  mercury  is  visible,  any  kind  of  cohe- 
sive gold  can  be  used  for  the  remaining  portion  of  the  filling. 
Fig.  339  presents  some  instruments  that  have  been  found 
especially  useful  in  this  work.  Tlie  gold  may  be  packed 
with  hand  or  mallet  pressure,  or  both. 

After  the  gold  is  all  packed  the  matrix  is  removed,  and 
the  filling  finished  with  sandpaper  disks,  strips,  burs,  and 
stones,  in  the  ordinary  manner.  For  finishing  the  amalgam 
portion  of  the  filling  only  fine  disks  or  strips  should  be  used. 
The  amalgam  being  yet  in  a  granular  condition,  and  not 
thoroughly  hard,  will  be  dragged  from  the  edges  somewhat 
and  made  slightly  imperfect  if  a  coarse  grade  of  sand  or 
emery  paper  be  used. 

The  gold  will  not  break  away  from  a  filling  made  in 
this  manner,  even  if  there  be  no  undercut  in  the  tooth  for 
holding  it ;  the  union  with  the  amalgam  will  be  quite  suf- 
ficient to  retain  it.     The  cavity  must  have  the  proper  shape, 


Gold-pnck- 
ing  instru- 
ments. 


358  COMBINATION  FILLINGS. 

however,  for  lioldino;  in  the  filling  as  a  whole,  the  same  as  if  it  were 
entirely  of  gold  or  amalgam. 

Cases  may  occur  where  it  does  not  matter  whether  the  amalgam 

and  gold  are  firmly  united  or  not ;  then,  instead  of  putting  the  plastic 

gold  into  the  amalgam,  soft  foil  may  be  used  against  it  in  the  manner 

described  for  the  combination  of"  soft"  and  "cohesive"  golds  (page  361). 

Having  become  familiar  with  the  simplest  form  of  fillings  of  amalgam 

and  gold,  it  will  be  well  now  to  go  a  step  farther,  and  take  up  some  of 

the  complications  that  constantly  occur.     Even  the   small   amount  of 

amalgam  that  is  used  will  sometimes  discolor  a  tooth  slightly,  especially 

if  the  buccal  wall  is  thin  or  if  the  tooth  is  not  of  very  dense  structure. 

When  there  is  danger  of  this  discoloration  taking  place,  it  can  be  largely 

prevented  by  placing  a  medium-sized  pellet  or  fold  of 

Fig.  340.         foil^    known    as    "gilded    platinum,"    against  the  buccal 

wall  of  the  cavity  before  putting  in  the  amalgam.     This 

foil  being  faced  with  platinum,  Mdiich  has  but  very  slight 

affinity  for  mercury,  the  amalgam    can    be    consolidated 

against  it  with  little  danger  of  discoloration  following. 

On  the  mesial  surface  of  bicuspids  and  molars  it  will 

o,  Amalgam;  6,     uot  be  cuough,  always,  to  put  the  gold  and  platinum  foil 

gold    extend-     affaiust  the   buccal  wall  ;  more  or  less  of  the  proximo- 

ing     on     the         '^  ^^  •  i  •  • 

buccal     side     buccal  surface  of  the  filling  being  exposed  to  view — i.  e. 
nearly  to  the     ^^^^^  hia<len  bv  the  tooth  anterior  to  it— it  would  look  badly 

gum  margin.  '  '  ^  '' 

if  made  of  amalgam  ;  consequently,  in  these  cases  the 
gold  must  be  carried  to  the  cervical  wall,  as  shown  in  Fig.  340,  the 
amalgam  occupying  a  triangular  space. 


Cement,  Amalgam,  and  Gold. 

There  are  many  teeth  with  very  large  cavities  and  frail  walls,  that 
can  be  rendered  serviccalde  for  years  and  made  to  look  surprisingly 
well  by  the  use  of  this  triple  combination.  For  instance,  a  molar  or 
bicuspid  having  lost  its  pulp  and  a  large  portion  of  its  crown,  and 
occu])ying  a  conspicuous  position,  presents  to  the  conscientious  denti.st  a 
serious  problem.  He  knows  that  if  filled  with  amalgam  it  will  be  an 
eyesore  to  every  one  by  its  unsightliness.  If  filled  with  gold  it  would 
take  hours,  and  exhau.st  both  patient  and  operator,  and  there  would  be 
every  probability  of  the  walls  soon  breaking  away  and  the  filling  com- 
ing out,  testifying  to  the  poor  judgment  of  the  operator  in  recommend- 
ing such  a  filling  under  such  circumstances.  If  filled  with  cement  it 
will  have  to  be  refilled  often,  and  with  each  refilling  would  more  than 
likely  be  somewhat  weakened.  The  loss  of  contour  by  the  wasting  away 
of  the  cement  will  allow  the  tooth  to  change  position,  and  its  usefulness 


GUTTA-PERCHA  AND  CEMENT. 


359 


will  gradually  be  lost,  and  the  tooth  sacrificed  because  the  dentist  did 
not  bring  the  requisite  amount  of  knowledge  and  skill  to  his  aid  to 
meet  the  opportunity  offered.  It  is  in  saving  such  teeth  as  these  that 
the  reputation  of  the  dental  profession  for  skill  and  usefulness  is  in- 
creased, and  honor  and  gratitude  are  accorded  to  the  men  who  can 
accomplish  it. 

The  method  of  procedure  will  vary  according  to  the  size,  shape,  and 
position  of  the  cavity.  If  small,  a  little  amalgam  can  be  put  into  the 
soft  cement  before  putting  on  the  matrix,  as  described  for  "  Cement  and 
Amalgam  "  A,  the  surplus  cement  removed  from  the  entire  edge  of  the 
cavity,  the  matrix  adjusted,  more  amalgam  put  in,  and  gold  added,  as 
described  for  "  Amalgam  and  Gold." 

In  larger  cavities,  involving  more  of  the  crown,  after  having  filled 
the  approximal  portion  of  the  cavity  with  the  cement,  amalgam,  and 
gold,  cement  should  be  put  in  a  second  time,  into  which  plastic  gold  is 
carried,  and  the  filling  completed  by  l^uilding  gold  on  to  that  wliich  was 
added  to  the  amalgam,  and  joining  it  to  that  which  was  put  into  the 
second  mix  of  cement. 

In  still  larger  cavities,  the   matrix   can  be  put  on  first,  amalgam 

packed  against  it  to  form  the  outer 

shell  of  the  approximal  side,  as 

described     for      "  Cement      and 

Amalgam "    B ;    cement  is   then 

put   into  the  body  of  the  tooth, 

and  into  this  gold  is  pressed  {not 

amalgam)    and    afterward  added 

to    until    it  joins    the    amalgam, 

thus     conij)leting     the     metallic 

shell.       From    the   specimen 

shown  in  Y'm.  341   the   matrix  has  been   i-emoved 

to  better  show  the  partially  completed  filling. 
It  will  be  seen  that  the  cement  plays  a  very  important  part  in  this 
operation.  It  will  preserve  the  color  of  the  tooth  though  it  may  have 
been  necessary  to  use  a  little  of  the  gilded  platinum,  or  to  have  the 
gold  extend  to  the  cervical  border  of  the  buccal  corner  of  the  cavity 
to  support  and  bind  firmly  together  the  tooth  and  filling,  yet  it  is  pro- 
tected from  external  influences  which  would  destroy  it.  Fig.  342  shows 
section  of  a  filling  of  cement,  amalgam,  and  gold. 


Fig.  341. 


c,  Amalgam  and  gold  to 
form  approximal  shell 
of  filling;  b,  cement 
and  gold  to  which  is 
to  be  added  gold  to 
complete  the  filling. 


a,  Cement ;    h,  amal- 
gam ;  c,  gold. 


Gutta-Percha  and  Cement. 
This  combination  is  extensively  used  for  what  may  be  termed  tem- 
porary work,  in  the  teeth  of  young  patients,  in  teeth  of  poor  quality, 
and  in  badlv  decayed  and  frail  teeth. 


3G0  COMBINATION  FILLINGS. 

It  is  generally  believed  that  /ine  ph<)S|)hate  will  not  last  as  well  at, 
or  just  under,  the  gum  margin  in  a])j)roxinuil  cavities  as  will  gutta- 
percha ;  although  exceptions  might  be  taken  to  such  a  general  rule.  It 
is  the  common  custom  to  combine  these  materials,  placing  the  gutta- 
percha at  cervical  margins,  using  the  cement  for  the  oc(;lusal  and  con- 
tour portions  of  the  filling. 

There  is  no  doubt  that  fillings  of  these  materials  last  much  better 
when  inserted  with  considerable  pressure,  thereby  condensing  well  and 
making  them  solid.  In  accomplishing  this,  the  matrix  is  of  great 
assistance.  It  not  only  allows  force  to  be  used  on  the  material  while 
in  a  plastic  state,  but  prevents  its  being  crowded  out  of  the  cavity  and 
up  into  the  gum,  and  leaves  the  filling  in  such  condition  that  but  little 
shaping  and  finishing  are  necessary. 

Any  suitable  matrix — the  one  previously  described  in  this  chapter 
is  recommended — having  been  adjusted,  gutta-percha  sufficient  to  fill 
the  cavity  a  little  below  the  gum  margin  is  carefully  packed  into  place 
with  warm  instruments.  Sufficient  heat  must  be  used  to  make  it 
thoroughly  plastic,  but  great  care  must  be  taken  not  to  burn  or  overheat 
the  material.  If  the  gutta-percha  is  overheated  its  physical  properties 
and  durability  are  very  much  impaired. 

All  cavities  where  gutta-percha  is  used  should  be  varnished  with  a 
thin  coating  of  white  resin  or  Canada  balsam  dissolved  in  chloroform. 
This  will  prevent  the  dragging  away  of  the  gutta-percha  from  the  walls 
of  the  cavity  in  finishing,  and  will  make  the  filling  water-tight. 

Sufficient  gutta-percha  having  been  put  in,  the  rest  of  the  cavity  is 
filled  with  cement.  The  matrix  being  in  place  and  properly  shaped,  the 
operation  is  reduced,  practically,  to  that  of  filling  an  occlusal  cavity. 

It  is  of  great  importance  that  the  cavities  be  ke])t  dry,  consequently 
the  rubber  dam  should  be  used  wherever  it  is  possible  to  do  so.  The 
cement  should  be  kept  dry  for  at  least  fifteen  minutes  after  it  is  put  in, 
and  then  covered  with  varnish  or  vaselin  to  prevent  the  disagreeable 
taste  due  to  its  acid  reaction,  also  to  keep  the  filling  for  a  still  longer 
time  from  the  saliva  after   the  dam  is  removed. 

Cement  will  wear  better  if  smooth  and  well  polished.  A  fine  glossy 
surface  can  be  obtained  with  an  oiled  burnisher  when  the  cement  is  at 
just  the  right  degree  of  hardness,  i.  e.  when  but  slightly  })lastic. 

A  convenient  method  of  oiling  burnishers  and  other  instruments  for 
plastic  fillings  is  to  place  on  the  back  of  the  third  joint  of  the  forefinger 
of  the  left  hand  a  bit  of  vaselin,  half  the  size  of  a  drop  of  water,  just 
before  beginning  to  put  in  the  filling.  The  instrument  can  be  readily 
touched  to  this,  and  it  quite  does  away  with  the  necessity  for  an  "  oil 
pad." 

An  excellent  lubricant  for  instruments  used  to  manipulate  gutta- 


GUTTA-PERCHA  AND   GOLD — VAEIOVS  KINDS  OF  GOLD.      361 

percha  or  cement  is  cocoa  butter.  A  small  porcelain  druggist's  jar 
into  Avhicli  it  has  been  melted  is  convenient  to  have  on  the  operating 
table.  Plastic  fillings  will  rarely  stick  to  instruments  that  have  been 
rubbed  on  cocoa  butter.  If  a  shaving  of  it  is  placed  on  a  completed 
cement  filling  it  will  instantly  melt  and  flow  over  the  entire  surface, 
preventing  the  disagreeable  taste  when  the  dam  is  removed,  and  will 
keep  it  from  contact  with  the  saliva  for  some  time. 

Gutta-percha  and  Gold. 

For  many  years  it  has  been  the  habit  of  some  good  operators  to  fill 
the  interior  of  large  cavities  with  gutta-percha,  covering  it  with  gold. 
Although  this  may  not  be  objectionable  practice  in  some  cases,  it  cer- 
tainly cannot  be  recommended  for  general  use.  The  jH'incipal  objection 
to  it  is  the  danger  of  frail  walls  being  fractured  by  the  subsequent 
expansion  of  the  gutta-percha.  So  many  instances  have  been  noticed 
where  fracture  has  followed  this  combination  that  the  fact  seems  well 
demonstrated  that  this  danger  exists.  Again,  there  is  no  need  of  com- 
bining these  two  materials  when  zinc  phosphate,  which  is  so  much 
better  dian  gutta-percha  for  this  purpose,  is  available  and  does  not  pos- 
sess the  dangerous  quality  of  expansion  attributed  to  gutta-percha. 

Gutta-percha  and  Amalgam. 

What  has  been  said  in  regard  to  gutta-percha  and  gold  will  apply 
equally  well  to  gutta-percha  and  amalgam.  Rarely,  if  ever,  can  this 
combination  be  used  to  so  good  advantage  as  can  zinc  phosphate  and 
amalgam. 

Various  Kinds  of  Gold  in  Combination. 

(A)  The  So-called  Plastic  or  Crystal  Mat  Gold,  with  Other 
Porms  of  Gold. — Within  a  few  years,  preparations  of  gold  other 
than  that  known  as  foil,  or  foil  made  into  cylinders,  ropes,  and  so 
forth,  have  been  introduced  and  have  become  of  great  value  in  the 
filling  of  teeth. 

These  golds  are  commonly  known  as  "  plastic  gold."  The  term  is, 
however,  misapplied.  The  granular  quality  of  these  gold  preparations, 
i.  e.  lack  of  fiber,  is  what  gives  them  their  peculiar  and,  for  certain 
purposes,  very  valuable  working  qualities.  To  understand  this  charac- 
teristic, take  a  ])iece  of  White's  "  crystal  mat  gold  "  and  place  it  upon 
a  piece  of  blotting  pa])er,  then  press  the  point  of  a  medium-sized  gold 
packer  upon  the  centre.  It  will  be  observed  that  when  the  pressure  is 
applied  the  gold  is  not  inclined  to  curl  up,  but  rests  in  its  flat  posi- 
tion, and  the  instrument  has  cut  a  clean  track  in  the  gold,  condensing 
only  that  which  is  directly  under  the  point.     The  gold  being  without 


362 


COMBINATION  FILLINGS. 


*'  fiber/'  so  to  speak,  the  particles  not  directly  under  the  point  are  not 
drawn  down  as  the  pressure  is  applied.  This  is  why  this  preparation 
of  gold  is  so  useful  for  starting  fillings. 

Now  take  a  cylinder  made  of  gold  foil,  ])lace  it  on  blotting  paper  as 
before,  and  with  the  same  instrument  press  on  the  centre  of  it.  It  will 
be  noticed  that  the  instrument  does  not  make  a  clean  cut  through  the 
cvlindei',  as  was  the  case  with  the  piece  of  mat  gold,  and,  instead  of 
remaining  flat  on  the  blotting  paper,  it  is  inclined  to  curl  up.  The 
fibrous  quality  of  the  foil  is  an  advantage  when  a  corner  is  to  be  built 
on  to  a  tooth,  or  in  any  place  where  toughness  of  the  material  assists  in 
its  manipulation. 

By  using  these  golds  for  starting  cavities,  the  peculiar  qualities  just 
referred  to  will  be  exhibited.  For  illustration,  we  will  take  an  extreme 
case — that  of  a  shallow  circular  cavity  in  the  buccal  surface  of  a  lower 
molar.  This  cavity  is  entirely  without  angles  or  undercuts,  its  walls 
flaring  outward,  the  bottom  being  flat, 
or  as  nearly  so  as  it  can  be  made  with 
a  large  bur  (see  Fig.  343).  A  piece  of 
plastic  gold  a  little  larger  than  the 
cavity  is  placed  in  position,  then  with 

Fig.  343. 


Fig.  344. 


Royce  pluggiug  instruments. 

a  flat,  very  slightly  serrated  instrument  (rr,  Fig.  339)  it  is  carefullv  and 
gently  worked  into  place.  When  it  is  condensed  al)out  even  with  the 
outer  edge  of  the  cavity,  a  smaller  instrument  is  used  to  condense 
around  the  edge.  As  (mly  the  portion  of  gold  under  the  point  is  dis- 
turbed, this  can  be  done  quite  readily  without  dislodging  the  whole  piece. 
Soon  sufficient  force  can  be  used  to  thoroughly  condense  the  whole. 
Care  must  be  used  in  selecting  a  first  piece  that  it  be  not  too  large,  but 
large  enough,  so  that  it  will  not  chop  up  as  it  is  being  manipulated. 
After  getting  the  first  piece  in  place,  the  filling  can  be  finished  with  the 
same  or  any  other  preparation  of  gold.  If  of  the  same,  it  is  well  to 
use  oval  points  (Fig.  344)  and  work  the  gold  toward  the  sides  of  the 
cavity  with  a  sort  of  rotary  motion,  keeping  the  edges  of  the  filling 
higher  than  the  centre. 

This  gold  is  very  soft  and  takes  a  very  sharp  impression  of  the  sur- 


VARIOUS  KINDS  OF  GOLD  IN  COMBINATION.  363 

face  on  which  it  is  packed,  as  shown  by  the  cross  lines  on  the  filling,  a, 
Fig.  343,  which  are  reproduced  from  those  made  in  the  cavity  shown 
at  b  in  Fig.  343.  The  lines  across  the  bottom  of  the  cavity  were  made 
with  the  sharp  point  of  a  hatchet  excavator. 

This  form  of  gold  can  be  used  to  advantage,  sometimes,  at  the  cervi- 
cal wall  of  compound  cavities,  provided  a  matrix  has  been  tightly  ad- 
justed. For  starting  fillings  in  approximal  cavities  in  the  front  teeth  it 
is  sometimes  invaluable,  and  it  can  be  used  in  conjunction  with  any  other 
form  of  gold,  or  interchangeably.  If  at  any  point  in  a  filling  the  oper- 
ator sees  a  place  where  he  thinks  he  can  put  a  piece  of  plastic  gold 
better  than  any  other,  there  is  no  reason  why  he  should  not  use  it. 
Sometimes  it  is  particularly  useful  to  thrust  into  soft  foil  to  make  a  sur- 
face upon  which  to  build  cohesive  foil.  It  can  be  packed  with  either 
Jiand  or  mallet  force,  and  with  smooth  or  serrated  instruments. 

(B)  Non-cohesive  and  Cohesive  Gold. — Strictly  speaking,  non- 
cohesive  gold  cannot  be  made  coliesive  by  annealing,  and  can  be  used 
only  on  what  is  known  as  the  "  wedge  "  principle.  "  Soft  gold,"  as  the 
term  is  generally  understood,  is  non-cohesive  when  used  without  anneal- 
ing, but  when  annealed  it  becomes  cohesive. 

Softness  and  toughness  are  the  qualities  necessary  to  make  tight  joints 
between  fillings  and  cavity  walls,  and  good  preparations  of  non-cohesive 
and  soft  golds  have  these  qualities.  Consequently,  a  method  that  Mill 
admit  the  use  of  these  golds  against  cavity  walls  with  a  sufficient  amount 
of  cohesive  gold  added  to  insure  strength  and  hardness,  when  strength 
and  hardness  are  necessary,  is  desirable. 

An  exaggerated  illustration  of  stopping  a  cavity  watertight  with  soft 
or  cohesive  gold  is  that  of  stopping  a  bottle  tightly  by  using  a  velvet 
<;ork  or  a  piece  of  hickory.  It  can  be  done  with  the  hickory,  but  the 
time  required  to  do  it  perfectly,  as  compared  with  doing  it  with  the 
velvet  cork,  is  not  unlike  the  difference  between  making  a  filling  of  soft 
and  one  of  cohesive  gold. 

Simple  cavities,  whether  in  occlusal  or  approximal  surfaces,  can  often 
be  half  or  two-thirds  filled  with  soft  gold  in  a  very  few  minutes,  and 
the  rest  of  the  cavity  filled  with  cohesive  gold.  A  filling  made  in  this 
manner  is  as  good  as,  or  even  better  than,  one  made  entirely  of  cohesive 
foil,  and  the  time  required  to  do  it  is  much  less,  as  the  soft  gold  can,  on 
account  of  its  softness,  be  used  much  faster  than  can  the  cohesive.  In 
cavities  of  easy  access  the  soft  gold  can  be  so  manipulated  as  to  be 
against  the  walls  of  the  cavity  at  every  point.  Small  cylinders,  or  any 
other  form  of  soft  gold,  can  be  set  around  the  edges,  and  the  central 
portion  of  the  cavity  filled  with  cohesive  gold.  Care  must  be  taken  to 
•carry  the  cohesive  gold  into  the  soft  with  instruments  not  too  large,  so 
that  a  mechanical  union  between  the  two  golds  is  effected,  as  but  little 


364  COMBINATION  FILLINGS. 

cohesion  can  be  had  between  soft  and  cohesive  gold.  Tn  large  cavities^ 
after  the  first  pieces  of  soft  gold  have  been  pnt  in  place  and  cohesive 
gold  worked  in,  the  two  kinds  of  gold  can  be  uavxX  interchangeably.  A 
piece  of  soft  gold  can  be  placed  against  a  portion  of  the  wall  of  the  cav- 
ity, followed  by  a  [)iece  of  cohesive,  which  is  first  attached  to  the  cohe- 
sive portion  of  the  filling  and  then  nsed  to  force  the  piece  of  soft  gold 
to  its  place.  Dexterity  and  tact  in  nsing  these  t^vo  golds  together  can 
only  be  obtained  by  experience,  and  carefully  noting  the  characteristics 
exhibited  under  manipulation. 

In  compound  cavities  soft  gold  })lays  a  most  important  part.  Fill- 
ings in  these  cavities  fail,  usually,  at  the  cervical  wall,  and  too  much 
care  cannot  be  taken  in  making  them  at  this  place  as  nearly  perfect  a& 
possible.  For  this  purpose  it  is  now  generally  conceded  that  soft  gold 
is  much  better  than  cohesive. 

A  suitable  matrix  will  greatly  facilitate  the  operation  and  assist  in 
obtaining  the  proper  contour.  The  thorough  packing  of  the  gold  will 
also  be  much  simplified  if  the  cavity  is  so  prepared  that  the  walls  form 
no  acute  angles  with  the  matrix,  therefore  attention  to  this  point  is 
important. 

A  matrix  having  been  properly  adjusted — the  one  described  under 
"  Amalgam  and  Gold  "  fillings  is  recommended — one-half  or  two-thirds 
of  the  approximal  portion  of  the  cavity  is  filled  with  soft  gold.  For  this 
purpose  soft  cylinders,  ropes,  pellets,  or  mats  can  be  used.  Great  care 
must  be  taken  in  condensing  the  gold  that  it  does  not  tilt  under  the 
instrument.  The  pressure  should  force  the  matrix  away  from  the  tooth 
enough  to  allow  the  gold  to  be  condensed  just  a  little  over  the  edge  of 
the  cavity,  so  that  when  the  burnisher  is  applied  there  will  be  sufficient 
gold  to  make  a  flush  filling. 

When  all  the  soft  gold  has  been  put  in  that  th(^  case  will  allow,  the 
cohesive  gold  should  first  be  added  in  very  small  pieces  in  order  to 
facilitate  the  driving  of  it  into  the  soft  gold,  so  as  to  make  a  strong 
union  between  the  two.  For  this  purpose  very  small  cohesive  cylin- 
ders or  No.  3  or  No.  4  foil  will  generally  be  used,  but  sometimes  No. 
30  or  No.  60  foil  or  some  of  the  plastic  or  crystal  gold  can  be  used. 
The  filling  can  be  finished  with  any  cohesive  gold,  that  kind  being^ 
selected  which  the  operator  has  found  by  experience  he  can  best  manipu- 
late under  the  existing  conditions.  He  will  also  remember,  as  the 
work  goes  on,  that  a  piece  of  soft  gold  laid  against  an  exposed  wall,, 
and  backed  uj)  with  cohesive,  as  before  described,  will  do  much  toward 
securing  a  good  filling. 

(C)  Soft,  or  Cohesive  Gold,  and  Heavy  Gold. — Fillings  of  soft 
or  cohesive  gold,  or  a  combination  of  the  two,  should  sometimes  be 
finished  with  heavy  gold.     Nos.  30,  40,   60,  and   sometimes   No.  120^ 


GOLD  AND   TIN—TIX-GOLD.  365 

can  be  used  to  advantage.  These  heavy  golds — which  are  usually 
rolled,  not  beaten — make  a  very  dense  filling,  and,  when  great  strength 
and  hardness  are  required,  they  are  preferable  to  lighter  grades. 

AVhen  a  filling  that  is  to  be  finished  with  heavy  gold  has  been 
brought  to  the  point  where  the  thick  gold  is  to  be  added,  the  surface 
should  be  as  nearly  level  as  possible,  as  it  is  difficult  to  adapt  the  heavy 
gold  to  indentations  and  irregularities.  The  instruments  used  should 
have  the  very  finest  serrations,  if  any  at  all.  The  gold  can  be  put  on 
by  hand  or  mallet  pressure,  or  by  burnishing  with  oval  points  having 
very  slight  serrations,  or  with  an  ordinary  burnisher.  AVhcn  done  in 
this  way  the  burnisher  is  apt  to  become  gold  plated,  and  the  instrument 
will  stick  to  and  drag  away  the  gold.  AVhen  this  happens  the  gold 
plating  can  be  removed  from  the  steel  by  rubbing  on  a  piece  of  ink 
■eraser,  or  on  flour-of-emery  paper. 

In  using  heavy  gold  great  care  is  necessary  that  no  portion  of  the 
piece  added  be  left  uncondensed.  Hard  pressure  must  be  applied  to 
every  part  of  the  gold,  or  it  will  flake  oif  and  destroy  the  good  appear- 
ance, if  not  the  utility,  of  the  filling. 

Gold  and  Tin. 

Compound  cavities  are  sometimes  partially  filled  with  tin  and  then 
finished  with  gold. 

At  the  present  time  it  is  a  disputed  question  whether  tin,  if  used  as 
above  suggested,  will  not  be  dissolved  out,  after  a  time,  by  the  action 
upon  it  of  the  fluids  of  the  mouth,  leaving  a  cavity. 

It  can  be  used  exactly  as  described  for  soft  and  cohesive  golds,  sub- 
stituting the  tin  for  the  soft  gold,  or  for  a  portion  of  it — for,  as  a  rule, 
much  less  tin  would  l)e  used  than  soft  gold. 

If  desired  enough  tin  can  be  used  to  cover  the  cervical  wall,  followed 
by  sufficient  soft  gold  to  complete  one-half  or  two-thirds  of  the  filling, 
the  final  finish  being  of  cohesive  gold. 

The  matrix  wull  be  found  of  the  same  service  as  in  the  case  of  soft 
and  cohesive  gold. 

Tin-Gold. 

The  term  "  tin-gold  "  has  been  applied  to  the  combination  of  tin  and 
gold  when  a  sheet  of  tin  and  a  sheet  of  gold  have  been  laid  one  upon 
the  other,  and  rolled,  folded,  or  crimped  together,  being  then  used  in 
the  same  manner  as  non-cohesive  foil,  depending  on  the  "  wedge  "  prin- 
ciple for  holding  in  the  filling.  Various  authorities  recommend  differ- 
ent proportions  of  the  tin  and  gold  to  be  used  in  this  manner.  All  the 
way  from  one-quarter  of  tin  to  three-quarters  of  gold,  /.  e.  the  propor- 
tion of  one-quarter  of  a  sheet  of  tin  and  three-quarters  of  a  sheet  of 


366 


COMB  IN  A  TION  FILLINGS. 


gold  to  bo  folded  or  crimped  together,  to  tliree-qnarters  of  tin  and  one- 
qnartcr  of  gold.     A  convenient  way  of  })reparing  "  tin-gold  "  for  use 

Fig.  345. 


Foil  crimpers. 


Fig.  346. 


Crimped  tin-gold. 


in    medium-sized    cavities    is  to  take   one-third    of  a   sheet  of  No.   4 
tin   foil,  upon  which  one-third  of  a  sheet  of  No.  4   non-cohesive  foil 

is  laid.  It  is  then  placed  upon 
crimpers  (Fig.  345)  and  drawn  into 
an  evenly  folded  mass  (Fig.  346). 

This  is  to  be  cut  into  lengths 
suitable  to  be  used  for  the  cavity  in 
hand.  These  pieces  can  be  doubled 
to  make  blocks,  or  rolled  around  a  broach  into  cylinders,  if  desired. 
For  larger  cavities  one-half,  two-thirds,  or  even  a  whole  sheet  each 
of  the  tin  and  gold  foils  can  be  used.  For  very  small  cavities,  one- 
quarter  sheet  of  each  may  be  sufficient. 

If  it  be  a  fact,  as  often  claimed,  that  tin  has  peculiar  preservative 
qualities  as  a  filling  material,  it  will  be  best  to  so  crimp  or  fold  the 
"  tin-gold  "  that  the  tin  will  be  on  the  outside,  in  order  that  it  may  be 
placed  against  the  cavity  walls. 

To  obtain  good  results  with  this  combination,  it  must  be  used  with 
the  same  care  and  accuracy  that  are  required  for  working  gold.  It  is 
very  tough  and  soft,  and  can  be  worked  with  great  rapidity  by  an 
expert.  For  method  of  using  see  chapter  on  Non-cohesive  Gold,  and 
work  "  tin-gold  "  as  there  described  for  non-cohesive  gold. 

After  a  filling  of  "  tin-gold  "  has  been  in  for  some  time  it  will  often 
be  found  to  have  changed  in  character,  and  instead  of  being  a  mass  of 
malleable  metal,  as  it  was  when  put  in,  t(.)  have  become  hard  and  brittle^ 
closely  resembling  amalgam,  but,  unlike  it,  will  not  stain  or  discolor 
the  teeth. 

"  Tin-gold "  is  recommended  for  use  in  the  temporary  teeth,  in 
occlusal  and  buccal  cavities  of  molars,  especially  in  teeth  of  poor  qual- 
ity, and  in  the  mouths  of  young  patients.     Small  approximal  cavities 


AMALGAMS  OF  DIFFERENT  QUALITY— CEMENT  AND  ALLOY.     367 

in  all  the  teeth  may  be  filled  with  it  to  good  advantage,  when  located 
where  its  dark  color  will  not  be  objectionable. 

"Tin-gold"  and  Gold. — "Tin-gold"  can  be  used  in  connection 
with  gold  in  the  same  manner  as  has  been  described  for  the  use  of  tin 
and  gold,  or  soft  and  cohesive  golds. 

Amalgams  of  Different  Quality  in  Combination. 

For  certain  amalgams  is  claimed  a  greater  preservative  character 
than  is  possessed  by  others.  But  on  account  of  very  dark  color  or 
little  edge  strength  ^  they  may  be  undesirable  for  the  surface  of  fillings, 
especially  wdien  contour  is  necessary,  or  when  prominently  exposed  to 
view. 

In  simple  cavities  it  is  very  easy  to  fill  nearly  full  with  the  amalgam 
deemed  best  for  its  preservative  qualities,  and  to  finish  with  that  having 
superior  color  or  edge  strength  as  the  case  may  require. 

For  compound  cavities  fill  about  tAvo-thirds  with  the  first-mentioned 
amalgam,  cutting  away  the  surfaces  and  exposing  the  entire  outer  rim 
of  the  cavity,  as  shown  in  Fig.  336.  The  matrix  is  then  adjusted  and 
the  remaining  portion  of  the  cavity  filled  with  amalgam  having  the 
requisite  edge  strength  for  contour  work. 

Cement  and  Alloy. 

Mixing  alloys  (such  as  used  for  amalgam)  with  cement  has  been 
recommended  to  a  certain  extent.  This  can  be  done  by  adding  from 
25  to  50  per  cent,  of  the  alloy  filings  to  the  cement  powder  and  then 
mixing  with  the  liquid,  or  the  alloy  may  be  worked  into  a  thin  mix  of 
cement. 

The  object  of  the  alloy  is  to  protect  the  cement,  in  a  measure,  from 
the  fluids  of  the  mouth,  thereby  making  the  filling  more  lasting. 

Another  combination  of  cement  and  alloy  which  has  proved  of  con- 
siderable worth,  especially  where  it  is  impossible  to  secure  proper  re- 
tention for  an  ordinary  amalgam  filling,  the  combination  having  a  very 
strong  adhesive  quality,  is  thus  described  by  a  well-known  writer: 

"  Ordinary  alloy  should  be  used,  and  not  the  recently  introduced 
quick-setting  varieties.  On  the  mixing  slab  should  be  placed  a  quantity 
of  zinc  oxid  powder  and  a  sufficient  quantity  of  the  liquid.  Now  mix 
the  alloy  in  the  usual  way,  but  do  not  express  the  mercury,  unless  in 
considerable  excess,  as  a  very  dry  mix  is  difficult  to  incorporate  with 
the  cement.  Mix  the  cement  as  usual  for  use  as  a  filling,  and  immedi- 
ately mix  in  about  an  equal  quantity  of  amalgam,  using  a  stiff  steel 
spatula.  The  white  metal  or  bronze  spatula  should  not  be  used,  as  it  is 
acted  upon  by  the  mercury.  Now  you  have  a  stiff  plastic  mass,  which 
^  See  Chapter  XIII.  ;  also  writings  of  Dr.  J.  Foster  Flagg. 


3G8  COMBINATION  FILLINGS. 

may  be  rolled  between  the  thumb  and  finger  into  a  convenient  pellet 
and  placed  entire  in  the  cavity,  pressing  carefully  to  place  with  smooth 
burnishers.  A  perfect  contour  may  be  built  uj)  without  the  aid  of  a 
matrix. 

"  Tiie  mixture  is  extremely  adhesive  to  the  dry  cavity  walls,  and  no 
definite  retaining  shape  is  needed.  Some  of  the  amalgam  may  be  saved 
unmixed  with  the  cement,  and  can  now  be  burnished  over  the  surface 
of  the  combination  filling,  to  which  it  adheres  almost  greedily,  and  thus 
a  pure  metallic  surface,  like  a  veneer,  is  given  it  which  is  as  durable  as 
an  amalgam  filling.  Or  a  quick-setting  amalgam  may  be  employed 
for  the  veneering. 

"  In  color  this  combination  is  like  amalgam,  but  is  more  granular  in 
appearance,  and  in  its  working  properties  resembles  stiff  cement.  When 
hard  it  takes  on  a  metallic  luster  under  the  burnisher  ;  if  sawed  through 
it  shows  a  metallic  surface.  It  is  less  soluble  in  the  oral  fluids  than 
oxyphosphate  cement,  but  less  durable  than  amalgam  alone,  except  when 
veneered  with  amalgam  as  described. 

"  Its  advantages  over  amalgam  are,  first,  its  adhesiveness,  which 
property  makes  it  applicable  to  cavities  in  which,  for  any  reason,  a  re- 
tentive form  cannot  be  obtained  ;  secondly,  the  rapidity  with  which  a 
large  cavity  can  be  filled,  a  valuable  item  where  dryness  cannot  be  long 
maintained,  and  making  it  unnecessary  to  employ  the  rubber  dam  in 
many  cases ;  thirdly,  the  ease  with  which  large  contours  may  be  made 
without  using  a  matrix. 

"  Its  advantages  over  cement  are  its  greater  hardness  and  durability, 
but  it  is  less  agreeable  in  color,  hence  should  be  employed  only  in  the 
posterior  teeth." 


CHAPTER  XV. 

RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS. 

By  Joseph  Head,  D.  D.  S.,  M.  D. 


Strictly  speaking,  the  term  inlay  may  be  applied  to  any  substance 
placed  in  a  tooth  cavity,  but  custom  has  restricted  this  term  to  fillings 
inserted  as  one  piece. 

In  primitive  times  teeth  were  filled  by  driving  a  solid  piece  of  lead 
into  the  cavity ;  gum  mastic  was  also  used  in  the  same  way ;  and  the 
green  stone  inlays  in  the  central  incisors  of  a  human  skull  discovered 
at  Copan,  Honduras,  probably  antedate  all  historical  record. 

Before  describing  the  construction  of  inlays  it  may  be  well  to  con- 
sider their  advantages  and  disadvantages ;  for  if  they  have  no  superi- 
ority over  other  fillings  to  counterbalance  their  inherent  defects,  inlays 
are  without  excuse  for  existence. 

Let  us,  therefore,  first  consider  the  main  characteristics  of  the  per- 
fect filling  ;  and  then  by  a  comparative  table  of  other  filling  materials 
the  good  and  bad  points  of  each  may  be  justly  examined. 

The  characteristics  of  an  ideal  fiUing  may  be  stated  as  follows : 

1.  Resistance  to  wear  of  mastication. 

2.  Resistance  to  action  of  oral  fluids. 

3.  Harmony  of  color. 

4.  Exclusion  of  bacteria,  and  preclusion  from  growth  of  those  that 
enter  the  margin. 

5.  Non-conductivity  of  heat. 

6.  Manipulation  easy  to  patient. 

7.  Manipulation  easy  to  operator. 

8.  Manipulation  not  destructive  of  healthy  tooth  structure. 

By  a  study  of  the  table  on  page  370  cohesive  gold  will  be  seen  to  pos- 
sess over  all  other  materials  the  sole,  though  imjiortant,  superiority  of 
greatest  edge  strength  and  resistance  to  the  crushing  force  of  mastication. 
True,  it  excludes  bacteria  from  the  cavity ;  but  experience  proves  that 
if  the  edges  of  a  cohesive  gold  filling  begin  to  leak  and  admit  micro- 
organisms, the  gold  seems  to  be  almost  entirely  lacking  in  the  antiseptic 
power  possessed  by  tin,  amalgam,  gutta-percha,  and  the  cements.     And 

24  ?.li!) 


370 


RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS. 


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BK  •§  1 

INLAYS  COMPARED    WITH  OTHER  FILLINGS.  371 

while  it  resists  perfectly  the  action  of  the  oral  fluids,  it  so  utterly  lacks 
the  other  ideal  attributes/ as  already  enumerated,  that  with  front  teeth, 
soft  teeth,  and  teeth  of  nervous  patients  its  manifest  disadvantages 
more  than  counterbalance  its  advantages. 

Soft  gold  is  open  to  the  same  objections,  but  it  has  the  advantages 
of  resistance  to  wear,  resistance  to  oral  fluids,  and,  to  a  less  degree, 
exclusion  of  bacteria. 

Tin  has  to  a  marked  degree  the  good  and  bad  attributes  of  soft  gold, 
but  it  turns  black. 

Amalgam  bulges  under  mastication,  chips  on  the  edges,  rusts,  and 
leaks ;  it  prevents  decay,  however,  through  antiseptic  action.  When 
rusty  it  is  a  moderately  poor  conductor  of  heat,  it  is  easy  of  adap- 
tation both  for  operator  and  patient,  and  calls  for  a  manner  of  manipu- 
lation that  is  conservative  of  healthy  tooth  structure.  It  is  therefore 
often  available  where  gold  is  not. 

Oxyphosphate  of  zinc  has  all  the  advantages  lacking  in  cohesive  gold 
with  the  exception  of  color,  and  lacks  all  the  advantages  that  cohesive 
gold  possesses.  Its  edge  strength  is  solely  due  to  its  great  adhesion. 
It  wears  under  mastication,  dissolves  in  the  fluids  of  the  mouth,  and 
usually  absorbs  bacteria ;  but,  on  the  other  hand,  it  prevents  the  growth 
of  germs,  is  a  non-conductor  of  heat,  has  better  color  than  gold,  is 
easy  of  insertion  for  patient  and  operator,  preserves  weak  walls,  and 
does  not  require  undercuts. 

The  same  may  be  said  of  oxychlorid  of  zinc,  except  that  it  causes 
pain  to  sensitive  dentin  and  exposed  gums. 

Gutta-percha,  in  a  similar  way,  with  the  exception  of  color,  possesses 
the  good  points  lacking  in  cohesive  gold,  and  lacks  the  good  points  pos- 
sessed by  cohesive  gold.  It  loses  shape  and  wears  under  mastication, 
has  feeble  resistance  to  fluids  of  the  mouth,  has  poor  color,  and  leaks 
micro-organisms  ;  but,  on  the  other  hand,  it  inhibits  from  further  growth 
the  germs  that  enter,  is  a  non-conductor  of  heat,  is  easy  of  insertion  for 
both  patient  and  dentist,  and  has  a  manipulation  that  tends  to  conserve 
frail  though  healthy  walls. 

When  we  come  to  inlays  we  have  a  filling  in  which  the  good  points 
of  the  cement  are  combined  with  those  of  amalgam,  gold,  or  porcelain 
in  such  a  way  as  to  insure  the  advantages  of  both  in  the  largest  degree, 
and  to  reduce  to  a  minimum  the  disadvantages  of  each. 

When  a  cavity  is  lined  with  a  thin  zinc  cement  squeezed  out  by  the 
insertion  of  soft  amalgam,  this  amalgam  afterward  having  as  much  as 
possible  of  its  mercury  removed  and  the  edges  of  the  metal  burnished 
to  the  cavity  margins,  an  inlay  of  amalgam  is  to  all  intents  and  purposes 
made.  This  treatment  takes  away  from  the  amalgam  three  of  its  objec- 
tionable features,  conductivity  of  heat,  lack  of  adhesion  to  the  cavity, 


372  RESTORATION  OF  TEETH  BY   CEMENTED  INLAYS. 

and  discoloration  of  adjacent  tooth  structure,  Avliile  tlie  adaptation  of 
the  phistic  metal  to  the  tooth  margins  can  he  ({uite  as  ])erfect  as  though 
no  cement  were  used.  So  in  using  the  principle  of  the  inlay  with 
amalgam  three  distinct  advantages  are  gained  without  any  counteracting 
disadvantages,  all  of  which  would  seem  to  indicate  that  whenever  possi- 
ble zinc  cement  should  be  used  under  amalgam. 

When  an  inlay  of  gold  is  cemented  into  a  cavity  with  oxyphosphate 
of  zinc  all  the  advantages  of  cohesive  gold  and  oxyphosphate  of  zinc  are 
obtained,  excepting  that  a  line  line  of  cement  remaining  at  the  margins 
may  in  time  prove  a  source  of  weakness.  Except  in  the  fine  line  above 
mentioned,  such  a  filling  com[)ared  with  the  ideal  filling  possesses  ex- 
cellent resistance  to  mastication  and  to  the  action  of  oral  fluids,  it  has 
power  to  restrain  the  growth  of  bacteria  that  may  enter,  it  is  a  non- 
conductor of  heat,  and  is  easy  for  the  patient,  while  the  manipulation 
involves  no  greater  labor  or  loss  of  tooth  structure  than  is  entailed  in 
the  use  of  cohesive  gold.  The  two  objections  that  can  be  raised  against 
the  filling  are  bad  color  and  an  edge  protected  by  a  soluble  cement. 
Hence — given  a  firm  tooth  structure  that  can  bear  the  mallet  without 
danger  of  being  crushed,  a  dentin  not  sensitive  to  thermal  changes, 
and  a  patient  not  too  severely  prostrated  by  the  necessary  malleting — a 
cohesive  gold  filling  is  superior  to  a  gold  inlay,  inasmuch  as  the  cohe- 
sive filling  may  have  edges  that  perfectly  exclude  bacteria,  even  though 
it  has  no  antiseptic  action.  Though  the  inlay  largely  inhibits  from 
growth  the  germs  that  enter  its  margins,  it  nevertheless  does  allow 
them  to  enter ;  and  the  filling  that  keeps  out  the  germs  entirely  must 
be  held  superior  to  the  filling  that  admits  germs  and  then  inhibits  or 
destroys  them.  Unfortunately,  in  the  soft,  sensitive  teeth  of  nervous 
patients  the  manipulation  of  cohesive  gold  does  not  result  in  the  exclusion 
of  decay  germs.  The  tooth  margins  are  powdered  or  weakened  in  some 
way  by  the  manipulation  or  apposition  of  the  gold,  and  the  entering 
germs  cause  rapid  decay,  the  cohesive  gold  not  having  the  antiseptic 
power  of  restraining  them.  The  thermal  shocks,  and  the  overwrought 
condition  of  the  patient  that  sometimes  lasts  longer  than  can  be  avoided, 
both  tend  to  produce  unhealthy  conditions  of  the  mouth  and  consequent 
tooth  dissolution.  In  such  a  mouth  the  inlay  is  indicated,  as  the  patient 
should  not  be  made  to  undergo  the  malleting  ;  and  since  the  germs  of 
decay  will  probably  enter  under  any  circumstances,  it  is  necessary  to  use 
a  filling  the  action  of  which  will  inhibit  or  prevent  their  growth. 

In  approximal  cavities  where  the  filling  does  not  show,  and  where 
great  resistance  to  the  percussive  force  of  mastication  is  necessary,  the 
gold  inlay  is  usually  to  be  preferred.  Its  sole  objection  is  the  fine  line 
of  cement  that  connects  it  with  the  cavity  walls ;  but  if  the  gold  inlay 
be   properly  prepared,  burnished,  and   finished  as  hereafter  described. 


PORCELAIN  COMPARED    WITH  OTHER  MATERIALS.  373 

this  line  of  cement  may  be  rendered  so  microscopic  as  to  become  prac- 
tically no  longer  a  source  of  danger.  In  other  respects  the  gold  inlav, 
when  not  visible,  approaches  very  nearly  the  requirements  of  the  ideal 
filling,  having  the  advantages  of  perfect  resistance  to  mastication,  pre- 
clusion from  growth  of  bacteria,  non-conductivity  of  variations  in  tem- 
perature, easy  manipulation,  firm  adherence  to  cavity  walls,  and  an 
adaptation  not  usually  so  expensive  to  tooth  structure  as  is  the  ordinary 
insertion  of  a  gold  filling. 

We  shall  now  speak  of  the  porcelain  inlay,  which  in  labial  and  buccal 
cavities  fulfills  more  nearly  than  any  other  the  characteristics  of  the  ideal 
filling.  Such  a  filling  may  possess  color  that  really  matches  the  tooth. 
It  may  be  set  with  a  cellulose  cement  that  almost  absolutely  resists  the 
oral  fluids.  It  excludes  germs  of  decay  and  precludes  from  growth 
those  that  enter.  A  porcelain  inlay  is  a  non-conductor  of  heat,  it 
adheres  to  cavity  walls,  its  manipulation  is  easy  to  the  patient,  and  is  con- 
servative of  tooth  structure.  The  only  real  objection  to  labial  porcelain 
fillings  is  in  the  fact  that  great  skill  and  patience  are  required  in  their 
insertion.  Where,  however,  porcelain  inlays  have  to  withstand  heavy 
strain  in  mastication,  as  in  Figs.  370,  375,  and  376,  they  are  liable  to  chip 
on  the  edges,  and  thus  to  demand  the  use  of  oxyphosphate  of  zinc  as  a 
cement.  This  objection,  therefore,  renders  them  somewhat  less  service- 
able than  gold  inlays  for  non-visible  approximal  cavities  in  molars  and 
bicuspids.  For  while  the  porcelain  is  sufficiently  strong  to  withstand 
the  crushing  force  of  mastication,  the  chipping  of  the  margin  tends  to 
accentuate  the  weakness  already  found  in  the  solubility  of  the  cement, 
which  is  its  sole  defence  against  bacteria.  If  such  chipping  occurs  on 
the  masticating  surface  of  the  molars  or  bicuspids,  the  fractured  mar- 
gins can  be  readily  filled  with  gold  in  such  a  way  that  edge  strength 
equal  to  gold  is  obtained.  Also,  if  the  edges  of  the  inlays  are  painted 
with  insoluble  cellulose^  before  the  filling  is  cemented  into  place,  all  the 
strength  and  adhesibility  of  oxyphosphate  of  zinc  can  be  combined. 
Thus  with  care  and  patience  the  porcelain  inlay  acquires  the  advantages 
of  gold,  cement,  and  porcelain,  while  it  has  none  of  the  usual  disad- 
vantages. The  porcelain  filling  properly  guarded  may  have  the  natural 
color  possessed  by  no  other  filling  material,  strength  to  withstand  masti- 
cation, resistance  to  the  fluids  of  the  mouth,  poAver  to  exclude  bacteria 
and  to  inhibit  the  growth  of  those  that  enter,  non-conductivity  of  heat, 
adaptation,  and  conservatism  of  tooth  structure.  And  if  at  times  the 
manipulation  for  the  dentist  is  of  necessity  so  deft  and  artistic  that  the 
highest  skill  and  judgment  are  required,  it  is  but  further  evidence  that 
the  finest  work  is  usually  the  most  difficult. 

^Tbe  Doyle  cement,  a  cellulose  cement,  is  claimed  to  be  permanent,  and  seems 
promising,  but  only  years  of  experience  can  prove  its  value. 


374 


RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS. 


The  Porcelain  Inlay. — The  work  of  manufacturing  and  manipu- 
lating porcelain  inlays  remains  to  be  considered. 

Pieces  of  porcelain  matching  the  natural  tooth  have,  in  times  past, 
been  ground  to  fit  the  cavities  and  then  held  in  position  with  cement. 
This  class  of  work,  however,  is  hardly  feasible  except  in  labial  cavities 
on  the  surfaces  of  the  front  teeth.     An  excellent  method  for  obtaining 

Fig.  347. 


a  /;  C  it  t 

a,  Defect  at  gingival  margin ;  6,  cavity  prepared ;  o,  mark  of  edge  on  tin  foil ;  d,  tin  foil  cut  out 

and  glued  to  artificial  tooth  ;  e,  piece  of  porcelain  ground  and  cemented  into  the  cavity. 

good  adaptation  is  to  proceed  as  follows  :  A  piece  of  tin-foil  should  be 
lightly  burnished  over  the  prepared  cavity,  as  in  Fig.  347,  6,  and  the 
edges  thoroughly  outlined  either  with  a  burnisher  or  a  plug  of  cotton 
lightly  pressed  into  the  cavity,  making  the  foil  appear  as  in  Fig.  347,  c. 

Fkx.  ;]48. 

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Porcelain  cavity  stoppers. 

The  foil  within  the  line  of  demarkation  is  then  cut  out  and  glued  to 
the  surface  of  a  piece  of  porcelain  that  matches  the  tooth,  as  in  Fig. 
347,  d,  the  porcelain  is  ground  away  up  to  the  edges  of  the  tin  on  all 
sides,  and  a  moderately  good  fit  is  thus  secured  (Fig.  347,  e).  This 
method,  however,  is  superseded  by  recent  discoveries  ;  but  for  those 
who  are  interested  historically  Fig.  347,  illustrating  the  steps  of  the 
operation,  may  prove  of  value.  Ready-made  porcelain  inlays  have  been 
kept  in  stock  for  years  at  the  dental  depots.  These  stoppings  are  of 
different  shapes  and  sizes,  and  are  intended  to  be  ground  to  fit  the  cav- 


THE  PORCELAIN  IN  LA  Y. 


375 


ities  and  finally  to  be  cemented  in  place  (Fig.  348).  Some,  however, 
instead  of  being  ground  to  fit  the  cavity,  reqnire  the  cavity  to  be 
ground  to  fit  them.  Dr.  George  H.  Weagant  has  devised  a  set  of 
instruments  suitable  for  this  purpose  (Fig.  349),  consisting  of  five  tre- 
phines of  consecutive  sizes  made  of  copper  charged  with  diamond 
dust.  These  instruments  are  intended  to  cut  pieces  of  porcelain  out  of 
an  artificial  tooth  that  matches  the  color  of  the  natural  tooth,  and  the 
cavity  in  the  natural  tooth  is  prepared  with  one  of  Dr.  How's  inlay 


Fig.  349. 


Fig.  350. 


Dr.  Weagant's  diamond  trephines. 


Dr.  How's  inlay  burs. 


Fig.  351. 


burs  (Fig.  350)  corresponding  in  size  to  the  trephine.  This  method  has 
several  serious  objections,  one  of  the  principal  being  that  in  order  to 
give  the  cavity  a  circular  shape  much  sound  tooth  structure  is  usually 
sacrificed.  Take  for  example  the  decayed  spot  shown  in  Fig.  351,  «. 
This  would  have  to  be  enlarged  as  in  Fig.  351,  6, 
— a  very  serious  objection. 

As  early  as  1882  Dr.  Herbst  advocated  glass 
fillings.  These  were  made  by  taking  impressions 
of  the  cavity  in  wax  and  making  two  moulds  in 
some  such  material  as  plaster  or  asbestos.  The 
ground  glass  was  then  flowed  into  the  first  mould, 
in  which  most  of  the  shrinkage  occurred.     The 

partly  formed  filling  w^as  then  removed  and  placed  in  the  second 
mould,  when  more  glass  was  added  until  the  filling  was  complete. 
Even  with  this  crude  method  the  results  were  fairly  satisfactory,  although 
the  margins  were  far  from  perfect  and  the  glass  was  permeable  to  such 
an  extent  as  to  blacken  ;  nevertheless,  fillings  M^ere  made  that  preserved 
the  teeth  for  years. 

In  1887  Dr.  C.  H.  Land  made  mechanically  perfect  edges  possible 
by  devising  the  metal  matrix.  He  used  both  gold  and  platinum,  but 
found  the  latter  preferable,  as  platinum  could  be  adapted  with  a  facility 
equal  to  gold,  and  allowed  the  use  of  a  high-fusing  tooth  body  much 
stronger  and  less  likely  to  deteriorate  than  bodies  capable  of  being  fused 


376 


RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS. 


on  gold,  these  of  necessity  requiring  so  large  a  percentage  of  glass  that 
they,  like  the  fillings  of  Herbst,  lacked  permanence  of  gloss  and  color. 
From  this  discovery  of  Land  dates  all  effective  porcelain  filling.  Before 
this,  pieces  of  porcelain  had  been  ground  to  fit  labial  cavities,  with 
fairly  good  results,  and  pieces  of  enamel  from  extracted  teeth  had  been 
inserted  in  a  similar  fashion,  but  the  accurate  adaptation  of  porcelain  to 
approximal  cavities  as  far  back  as  the  molars  was  impossible  until  the 
metal  matrix  was  evolved. 

At  present  the  advocates  of  porcelain  fillings  are  represented  by  two 
distinct  parties  :  those  who  advocate  a  low-fusing  porcelain  that  can  be 
melted  in  a  gold  matrix,  and  those  who  advocate  a  porcelain  of  a  fusing- 
point  and  resistance  at  least  equal  to  Close's  continuous-gum  body, 


Fig.  352. 


I 


12  3  4  5  6 

Diamond  points,  Nos.  1  to  6 ;  a,  copper  disk  charged  with  diamond  dust. 

necessitating  the  use  of  platinum  for  the  matrix.  It  is  claimed  by  the 
advocates  of  low-fusing  porcelains  that  gold  can  be  more  perfectly 
adapted  as  a  matrix  than  platinum.  This,  if  true,  is  a  very  important 
advantage.  But,  on  the  other  hand,  those  advocating  high-fusing 
porcelains  believe  that  they  can  get  as  perfect  an  adaptation  with 
platinum  as  with  gold,  and  that  their  porcelains  have  a  better  color, 
are  stronger,  more  durable,  and  more  easily  manipulated,  thus  giving  to 
the  work  a  far  wider  range  than  seems  possible  with  any  low-fusing 
bodies  yet  devised,  for  porcelains  seem  to  have  strength  and  durability 
in  direct  proportion  to  their  fusing-points.  In  this  connection  we  should 
remember  that  when  brilliant  men  of  the  past,  through  long  series  of 
experiments,  were  perfecting  the  process  of  continuous-gum  work,  they 
would  undoubtedly  have  adopted  the  low-fusing  bodies  had  they  found 
any  that  would  melt  on  gold  and  remain  permanent.  That  they 
finally  resorted  to  platinum  and  made  durable  porcelain  bodies  at  their 
present  fusing-points  would  seem  to  indicate  that  low-fusing  porcelains 


THE  PORCELAIN  INLAY. 


2>11 


are  unable  to  withstand  the  solvent  action  of  saliva  and  the  force  of 
mastication. 

The  preparation  of  the  cavity  for  either  high-fusing  or  low-fusing 
porcelains  is  identical.    The  cavities  should  be  free  from  undercuts.    If 

Fig.  353.  Fig.  354.  Fig.  355.  Fig.  356.         Fig.  357.         Fig.  358. 


these  are  unavoidable  through  extensive  decay,  the  cavity  should  first 
be  filled  with  oxyphosphate  of  zinc.     The  edges  should  be  sharp  and 


378 


RESTORATION  OF  TEETH  BY  CEMaNTED  INLAYS. 


smooth,  and  where  they  arc  approximal  there  must  be  sufficient  separa- 
tion to  allow  the  metiillic  matrix,  or  mould,  to  be  withdrawn  without 


Fig.  359. 


A,  Outline  of  labial  cavity  ;  B,  platinum  foil  large  enough  to  be  readily  held  immovable  by  the 
first  and  second  fingers  during  the  formation  of  the  matrix. 

distortion,  as  success  is  impossible  with  a  distorted  matrix.     The  final 
polishing  can  be  best  accomplished  with  a  set  of  diamond  points  (Fig.  352). 

Fig.  360. 


A,  Outline  of  cavity  in  distal  aspect  of  lateral  incisor :  B,  platinum  folded  over  cutting  edge  to 
insure  immobility  and  to  give  outlines  of  tooth  so  that  a  perfect  contour  of  porcelain  may  be 
obtained. 

The  separation  may  be  obtained  with  rubber,  cotton,  or  tape.     Approx- 
imal cavities  between  front  teeth  may  be  sometimes  advantageously  cut 


THE  PORCELAIN  INLAY. 


379 


freely  away  from  the  back,  as  in  Fig.  374,  «,  6,  c,  d.  When  the 
fillings  are  between  bicnspids  the  palatal  or  lingual  walls  should  be  cut 
unsparingly  whenever  it  is  necessary.  Where  the  filling  is  to  stand  the 
force  of  mastication  the  edges  of  the  cavity  should  be  at  least  at  right 
angles  to  the  grinding  surface,  as  in  Figs.  370  and  375.  The  prepara- 
tion of  the  cavity  being  completed,  if  high-fusing  porcelain  is  to  be 
used  the  matrix  must  be  made  with  rolled  platinum  one  one-thousandth 
of  an  inch  in  thickness.  If  found  desirable,  thinner  platinum  may  be 
used  for  small  cavities ;  but  the  firm  burnishing  required  usually  re- 
duces the  foil  of  one  one-thousandth  of  an  inch  to  one  three-thousandth 

Fig.  361. 


A,  Cavity  in  anterior  approximal  surftice  of  first  molar. 


or  one  four-thousandth  of  an  inch  on  the  margins,  where  excessive 
thickness  of  the  metal  is  objectionable.  Foil  thinner  than  one  one- 
thousandth  of  an  inch  seems  to  lack  sufficient  body  to  stretch  properly 
Avithout  tearing.  This  platinum,  if  annealed  in  a  Bunsen  burner  or 
blowpipe,  will  be  harsh  and  unfit  for  use,  but  when  annealed  in  a  muffle 
or  electric  furnace  it  becomes  soft  and  tough.  The  platinum  is  placed  im- 
movably over  the  cavity  and  spun  into  all  parts  with  a  ball  burnisher 
(Figs.  353  and  354),  great  care  being  taken  to  define  the  edges  sharply 
and  smoothlv.  The  edges  that  wrinkle  mav  be  flattened  and  smoothed 
with  the  broad  surfaces  of  the  spatula  shown  in  Fig.  356.  Should  the 
bott(Hu  tear,  it  is  of  little  moment  as  long  as  the  edges  are  smooth  and 
intact.     Sometimes  it  is  useful  to  form  the  matrix  by  driving  the  metal 


380 


RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS. 


into  all  the  recesses  with  cotton ;  bnt  while  this  is  undoubtedly  of 
advantage  in  some  instances,  the  careful  spinning  of  a  piece  of  foil 
from  the  edges  to  the  cavity  floor  will  generally  give  the  best  results. 
The  soft,  unburnished  platinum  takes  a  beautiful  impression,  but  when 
the  metal  has  been  burnished  it  becomes  elastic;  if  therefore  the  matrix 
be  moved  during  its  formation,  an  accurate  impression  is  impossible, 
for  the  elastic  platinum  when  distorted  cannot  be  forced  back  accurately 
into  position  until  it  has  been  rcannealed.     When  complaint  is  made 


Fig.  362. 


A,  Posterior  approximal  cavity  in  second  bicuspid  ;  B,  edge  of  platinum  extending  over  first 

bicuspid  to  insure  mobility. 

against  platinum  by  the  advocates  of  gold  matrices  it  probably  arises 
from  the  fact  that  they  try  to  work  the  platinum  in  the  same  manner 
as  gold. 

The  matrix  when  finished  should  be  carefully  removed  and  heated 
to  redness  in  order  to  destroy  all  organic  material,  as  such  material  will 
tend  to  destroy  the  true  shade  of  the  porcelain. 

In  labial  cavities  the  piece  of  platinum  should  be  cut  sufficiently 
large  to  extend  beyond  the  two  adjacent  teeth,  and  the  metal  should  be 
moulded  to  the  three  teeth  by  pressure  with  cotton  and  bibulous  paper. 
The  metal  is  then  held  firmly  upon  the  two  adjacent  teeth  by  the  first 
and  second  fingers,  as  in  Fig.  359,  when  the  general  directions  for  adjust- 
ing the  matrix  to  the  cavity  may  be  readily  carried  out.  The  large 
piece  of  platinum  has  two  great  advantages  :   it  conduces  to  immobility 


THE  PORCELAIN  INLAY. 


381 


of  the  metal  during  the  formation  of  the  matrix,  and  it  gives  the  entire 
labial  form  of  the  tooth,  so  that  an  accurate  idea  may  be  obtained  of 
the  desired  contour  of  the  filling. 

In  corners  of  centrals,  as  in  Fig.  360,  the  platinum  should  be  folded 
well  over  the  labial  and  palatal  surfaces  of  the  tooth ;  then  it  should 

Fig.  363. 


A,  Outline  of  approximal  cavity ;  B,  ilap  of  platinum  that  had  been  cut  away  and  turned  back  to 
facilitate  the  removal  of  the  matrix. 

also  be  bent  over  the  cutting  edge,  forming  a  sort  of  cap,  beneath  which 
shows  the  entire  contour  of  the  tooth,  and  by  means  of  which  entire 

Fig.  364. 


A,  Outline  of  cavity  as  formed  in  platinum  matrix  ;  B,  clamp  holding  platinum  immovable  while 
the  matrix  is  being  burnished  into  place. 

immobility  may  be  obtained  while  the  cavity  margins  are  being  defined 
and  the  matrix  formed. 

The  same  principle  applies  in  forming  a  half  cap  from  a  large  piece 
of  platinum  for  the  approximal  cavities  of  bicusjHd.'S  and  molars.  The 
platinum  should  extend,  as  in  Figs.  361  and  362,  from  grinding  edge  to 
cervical  margin,  and  along  the  sides  of  the  adjacent  tooth.     This  can  be 


382 


RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS. 


firmly  held  with  the  index  and  middle  fingers  of  the  left  liand,  while 
the  right  hand  presses  the  metal  with  cotton  partly  into  the  cavity.  The 
margins  and  floor  of  the  matrix  may  then  be  defined  with  a  bnrnisher. 

In  mesial  cavities  the  metal  must  be  pushed  away  from  the  operator 
and  the  work  accomplished  by  means  of  the  index  and  middle  fingers, 
as  in  Fig,  301,  In  distal  cavities  the  metal  is  pulled  toward  the  oper- 
ator, who  works  around  and  beyond  the  hand,  holding  the  platinum  as 
in  Fig.  362. 

When,  as  sometimes  occurs,  the  adapted  platinum  is  dovetailed 
around  the  teeth,  so  as  to  render  its  removal  difficult  or  impossible  with- 

FiG.  365. 


Position  of  fingers :  left  lower  bicuspid. 


out  distortion,  the  outer  edge  of  the  platinum  cap  may  be  split  with  a 
sharp  knife  from  the  gum  line,  just  beyond  the  cavity  margins,  as  is 
shown  in  Fig.  363.  Fig.  364  shows  a  method  of  obtaining  immobility 
of  the  matrix  by  a  clamp  that  sometimes  proves  useful.  Figs.  365 
and  366  show  the  position  of  the  fingers  when  manipulating  the 
matrix  on  the  lower  teeth.  This,  of  course,  should  be  done  while  the 
matrix  is  held  motionless  in  the  cavity.  It  is  sometimes  advisable,  in 
order  that  perfect  immobility  may  be  obtained,  first  to  pack  the  matrix 
full  of  bibulous  paper  or  cotton.      When  this  is  done  and  the  packing 


THE  PORCELAIN  INLAY. 


383 


removed  there  will  be  no  difficulty  in  teasing  out  an  undistorted  matrix 
from  the  cavity. 

The  color  of  the  filling  must  next  be  decided  by  means  of  a  shade 
ring.  The  basal  color  of  nine-tenths  of  all  porcelain  fillings  is  light 
yellow,  and  white  added  according  to  necessity  will  in  a  large  number 
of  cases  be  all  that  is  required  to  obtain  a  perfect  match.  Whatever  tint 
is  desired,  the  basal  color  should  be  first  ascertained,  when  the  correct 
toning  material  may  be  added  with  comparative  ease.  The  thoroughly 
mixed  body,  being  wet  with  distilled  water  and  dried  \vith  blotting-paper 
to  the  consistence  of  dough,  is  placed  in  the  matrix  on  the  point  of  the 
brush  or  spatula  (Figs.  357  and  358),  and  settled  to  the  bottom  with  a 
few  taps  on  the  pliers  that  hold  the  platinum.    The  porcelain  should  not 


Fig.  366. 


Position  of  fingers :  right  lower  bicuspid. 

be  allowed  to  come  quite  to  the  edge.  After  it  has  been  carefully  dried  by 
turning  it  face  downward  on  a  piece  of  soft  muslin,  the  filling  is  placed 
in  an  electric  or  gas  furnace,  as  the  case  may  be,  and  baked  until  a  gloss 
appears.  It  is  then  removed,  cooled,  and  placed  again  accurately  in  the 
cavity,  and  the  edges  once  more  burnished  down. 

This  second  burnishing  is  the  most  important  part  of  the  operation, 
for  however  perfect  the  first  adaptation  may  have  been,  the  edges  must 
of  necessity  be  warped  in  the  furnace  by  the  unequal  expansion  and 
contraction  of  the  porcelain  and  platinum.  This  contraction  having  for 
the  most  part  occurred,  a  second  burnishing  makes  an  adaptation  that 
may  be  practically  perfect.  The  pai-tially  filled  matrix  must  then  be 
removed,  filled  up  to  the  edges  with  porcelain  paste,  and  finally  baked. 


384  RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS. 

A  third  addition  of  porcelain  may  be  needed,  but  this  is  usually  unnec- 
essary. After  baking,  the  filling  may  be  taken  from  the  furnace  almost 
immediately,  as  practically  only  very  large  pieces  need  to  be  cooled 
slowly,  although  theoretically  a  gradual  cooling  will  make  the  porcelain 
tougher.  The  platinum  should  now  be  stripped  off,  care  being  taken 
to  pull  it  away  from  the  edge.  Should  it  be  pulled  off'  toward  the  edge, 
chipping  is  likely  to  occur.  If  small  portions  of  platinum  stick  to  the 
porcelain,  they  can  be  peeled  off  with  a  sharp,  tempered,  pointed 
instrument. 

The  filling  is  now  ready  for  insertion.  Undercuts  may  be  carefully 
made  in  the  cavity  and  grooves  made  in  the  porcelain,  by  using  a  thin 
copper  disk  (Fig.  352,  a)  charged  with  diamond  dust,  so  as  not  to  mar 
the  edges.  This  is  usually,  if  the  proper  method  is  employed,  a  safe  and 
easy  procedure  with  the  smallest  fillings.  The  disk  and  porcelain  must 
be  kept  thoroughly  wet  during  the  cutting  of  the  grooves.  The  inlay 
should  be  so  held  that  the  edge  adjacent  to  the  intended  groove  may  be 
buried  in  the  skin  of  the  finger ;  the  groove  can  then  be  fearlessly  made 
by  the  swiftly  revolving  disk  that  cuts  only  the  hard  porcelain  and 
pushes  back  the  yielding  tissue  of  the  finger  without  inflicting  injury. 
If  the  porcelain  is  blackened  by  the  powdered  copper,  the  discoloration 
may  be  readily  removed  by  a  strong  jet  of  water  thrown  upon  it.  If, 
however,  the  undercuts  are  not  deemed  feasible  or  sufficient,  the  gloss 
from  the  under  side  should  be  removed  with  a  sandpaper  disk  or  with 
hydrofluoric  acid.  For  etching  with  the  hydrofluoric  acid  the  following 
method  should  be  pursued :  The  face  of  the  filling  should  be  imbedded 
in  a  piece  of  soft  base-plate  wax,  leaving  free  the  porcelain  that  is  to 
enter  the  cavity.  A  drop  of  hydrofluoric  acid  is  then  placed  upon  the 
porcelain  and  left  there  for  about  five  minutes,  when  wax  and  porce- 
lain may  be  washed  in  water  and  the  filling  removed  from  the  base 
plate.  The  under  side  will  be  frosted  and  the  cement  will  adhere  to  it 
fairly  well,  but  not  so  well  as  though  efficient  grooves  had  been  obtained. 
The  filling  and  the  cavity  should  next  be  washed  in  alcohol  and 
thoroughly  dried.  The  rubber  dam  may  often  be  put  on  with  advan- 
tage just  before  the  filling  is  inserted,  although  the  thorough  dryness 
of  the  tooth  thus  obtained  will  at  first  tend  to  make  the  filling  appear 
too  dark. 

In  a  buccal  or  labial  cavity,  where  no  force  of  mastication  is  to 
be  withstood,  the  transparent  cellulose  cement  may  be  advantageously 
used.  If  this  cement  proves  to  be  durable  and  sufficiently  adhesive  it 
will  be  a  great  desideratum,  for  a  translucent  insoluble  cement  is  the 
one  thing  lacking  to  make  porcelain  fillings  practically  perfect;  but 
great  care  should  be  observed  in  its  use.  The  dried  cavity,  well  under- 
cut, should   be  filled   with   the  cement.     The  cement  should  then   be 


THE  PORCELAIN  INLAY.  385 

painted  all  over  the  under  side  of  the  porcelain  filling,  so  that  the  under- 
cuts may  be  well  filled.  These  coatings  should  then  be  allowed  to  dry 
to  the  consistence  of  a  thick  jelly,  when  the  filling  is  put  into  the  cavity 
and  ironed  into  place  with  a  hot  instrument.  The  cement  sets  hard 
only  through  evaporation  of  the  solvent,  and  if  the  filling  is  too  soon 
inserted  it  will  act  as  a  stopper,  preventing  the  hardening  of  the  cement. 

Where  great  strain  is  brought  to  bear  upon  the  filling,  or  where  the 
cavity  is  not  deep  enough  to  Avarrant  the  use  of  any  but  the  most 
adhesive  cement,  oxyphosphate  of  zinc  should  be  used.  The  rubber 
dam  should  be  applied  wherever  practicable.  The  filling  and  cavity 
should  be  carefully  undercut  and  dried  in  alcohol.  Creamy,  slow-set- 
ting oxyphosphate  of  zinc,  corresponding  in  color  as  nearly  as  possible 
to  the  tooth,  should  then  be  placed  in  the  cavity,  and  the  filling,  picked 
up  by  means  of  a  little  cement  on  the  spatula,  be  pressed  home.  The 
porcelain  should  be  held  in  position  for  a  minute  or  two  until  the  oxy- 
phosphate has  lost  its  elasticity  ;  for,  however  perfectly  the  porcelain 
filling  may  have  been  fitted,  if  it  does  not  go  accurately  into  place  the 
edges  will  be  as  imperfect  as  though  an  ill-adapted  matrix  had  been 
used.  As  before  mentioned,  a  creamy,  slow-setting  cement  is  essential, 
and  up  to  the  present  time  the  Harvard  cement  seems  best  to  satisfy 
these  requirements.  When  the  filling  is  finally  in  position  the  setting 
of  the  cement  may  be  hastened  by  a  blast  of  hot  air  or  a  hot  instru- 
ment applied  to  the  porcelain.  When  the  cement  is  wiped  away  and 
the  tooth  cleaned,  paraffin  or  varnish  should  be  flowed  over  the  filling, 
in  order  that  the  cement  may  set  for  six  hours  before  it  is  exposed  to 
the  action  of  the  saliva.  On  the  following  day  the  edges  may  be 
ground  with  an  Arkansas  stone  or  polished  with  sandpaper.  It  is 
better  for  finishing  that  the  edges  should  be  a  little  too  low  than  too 
high.  If,  however,  the  porcelain  is  too  high  it  can  be  ground  down 
and  still  give  good  results ;  but  the  original  gloss  is  in  most  cases  to  be 
preferred.  Having  described  the  general  operation  of  putting  in  a 
porcelain  filling,  a  few  cautions  may  not  be  out  of  place  before  describ- 
ing the  special  operations. 

A  filling  smaller  than  a  pinhead  should  not  be  attempted,  as  good 
edges  can  hardly  be  obtained.  Simple  circular  cavities  without  com- 
pound curves  in  the  margin  frequently  require  only  one  burnish, 
especially  if  they  be  small,  as  the  contraction  of  the  fused  porcelain  is 
often  less  than  the  probable  personal  error  of  the  operator. 

Labial  cavities  should  be  made  deep  if  good  color  and  adhesion  are 
desired.  A  bar  of  porcelain  running  into  the  tooth  makes  a  much 
stronger  anchorage  than  a  platinum  pin,  as  the  platinum  may  stretch 
and  it  always  tends  to  weaken  the  substance  of  the  body. 

In  large  contours  excessive  contraction  may  be  avoided  by  adding  one 

25 


386  RESTORATION  OF  TEETH  BY  CEMENTED   INLAYS. 

\)\\yt  ill  four  of  a  colorless  high-fiisino;  powder  to  that  part  of  the  mixed 
eiiaiucl  which  is  to  be  used  for  the  first  baking.  The  unfused  particles 
extend  across  the  matrix  in  every  direction,  making  what  is  practically 
an  internal  investment.  The  slight  lightening  thus  occasioned  is 
entirely  overcome  by  the  second  coat,  and  the  jjropcr  contour  is  obtained 
in  fewer  bakings.  When  handling  small  fillings,  the  pliers  and  cavity 
may  be  advantageously  kept  wet  up  to  the  time  of  insertion,  as  capillary 
attraction  will  prevent  the  filling  being  dropped  and  lost.  To  place  a 
tiny  filling  on  the  operating-case  in  the  same  relative  position  that  it 
will  take  in  the  tooth  prevents  mistakes  as  to  which  side  should  go  in 
first. 

In  addition  to  the  classification — labial,  buccal,  approximal,  contour, 
etc. — porcelain  fillings  are  to  be  considered  in  regard  to  their  position 
in  the  mouth,  viz.  fillings  that  keep  their  color  when  cemented  into 
place,  and  those  that  will  be  darkened  by  the  consequent  shadow.  Unless 
these  classifications  are  understood,  many  a  well-matched  porcelain  inlay 
will  end  by  appearing  dark  and  unsightly  in  the  mouth.  Color  varia- 
tions are  met  similar  to  those  that  are  seen  upon  examining  a  piece 
of  window-glass.  The  surface  may  be  nearly  colorless  while  the  edge  is 
dark  green.  The  color  of  porcelain  fillings  is  dependent  u})on  the  per- 
fection with  which  the  light  is  reflected  to  the  eye  of  the  observer.  For 
instance,  in  a  perfect  light,  yellow  porcelain  is  yellow,  because  all  of  the 
other  rays  that  make  up  light  are  absorbed  and  only  the  yellow  are 
reflected  to  the  eye.  If  the  light  be  gradually  decreased,  fewer  yellow 
rays  will  be  reflected,  and  the  color  will  become  darker ;  when  there  is 
no  light  reflected  the  porcelain  will  appear  black.  The  more  perfect  the 
front  and  side  lights  in  porcelain  fillings  the  less  will  be  the  shadow- 
variations  in  color.  Take,  for  example,  a  simple  labial  cavity,  as  illus- 
trated in  Fig.  367.  If  this  extend  into  the  dentin  sufficiently  deep  to 
prevent  the  color  of  the  oxyphosphate  of  zinc  or  of  any  other  cement 
shining  through  it,  the  correct  color  of  the  porcelain  will  be  given. 
If,  however,  we  place  this  well-matched  material  on  the  approximal 
surface  of  the  tooth,  as  in  Fig.  368,  with  an  adjacent  tooth  shutting 
off"  direct  reflection,  and  thus  allowing  only  indirect  rays  to  meet  the 
eye  of  the  observer,  the  color  will  be  lost  in  shadow,  and  from  having 
been  a  perfect  match,  or  nearly  so,  the  shade  w'ill  assume  a  dull  lead 
color.  Also,  if  in  Fig.  367  the  labial  cavity  should  penetrate  entirely 
through  the  tooth,  through  the  palatal  enamel,  the  inlay  would  present 
a  problem  of  almost  insurmountable  difficulty  ;  for  nearly  all  of  the 
direct  rays  would  pass  through  it  and  would  be  lost  in  the  shadows 
of  the  mouth,  while  the  side  lights  would  be  shut  off  by  the  non- 
transparent  but  necessary  zinc  cement.  This  difficulty  may  be  over- 
come by  placing  two  fillings,  one  on  the  palatal  and  one  on  the  labial 


THE  PORCELAIN  IXLAY.  387 

surface.  The  oval  inlay  running  through  the  entire  tooth  substance  is 
mentioned  only  as  an  illustration  of  the  greatest  amount  of  color  varia- 
tion to  be  met  with ;  and  the  nearer  that  a  porcelain  inlay  approximates 
to  this  condition  the  greater  will  become  the  tendency  of  the  color  to 
be  lost  in  shadow. 

Take,  for  further  example,  the  two  fillings  shown  in  Fig.  369.  In 
each  illustration  the  fillings  go  evenly  through  the  labial  and  pal- 
atal walls  of  the  enamel,  and  yet  if  both  fillings  are  made  of  material 
that  matches  the  tooth  substance  the  corner  inlay  will  look  well,  while 
the  halfmoon-shaped  filling  will  be  dark.  If,  however,  h  docs  not  go 
through  the  palatal  wall  and  the  cement  extends  entirely  behind  it,  its 
color  will  be  nearly,  if  not  quite,  as  good  as  that  of  the  corner,  it 
having  almost  assumed  the  classification  of  the  simple  labial  cavity 
before  mentioned.  The  diiference  in  the  shades  of  these  two  fillings 
may  be  explained  as  follows  :  The  corner  (a)  is  illuminated  by  side 
light  from  the  cutting  edge,  Avhile  the  halfmoon-shaped  filling  (6)  is 
shut  in  on  four  sides,  on  three  by  cement  and  on  the  fourth  by  the  adja- 
cent tooth.     It  must  be  further  noted  with  reference  to  the  corner  (a). 

Fig.  367.  Fig.  36S 


that  if  it  is  looked  at  from  directly  in  front,  or  from  the  direction  of 
the  arrow  X  toward  the  cement,  the  color  will  be  good ;  if,  however, 
it  is  looked  at  away  from  the  cement,  as  indicated  by  the  arrow  Y,  the 
color  will  be  lighter  or  darker  according  to  the  intensity  of  the  light ; 
but  the  true  color  will  not  be  seen.  This,  however,  is  not  a  serious 
obiection,  as  the  filling  is  usually  seen  from  directly  in  front,  and  the 
occasional  side  views  are  equally  divided  between  good  and  bad  lights. 
We  may,  therefore,  feel  that  a  corner  inlay  which  does  not  include 
more  than  a  third  of  the  tooth's  cutting  edge  is  an  inlay  fiivorable  to 
the  obtaining  of  a  good  match.  Buccal  fillings  in  bicuspids  and  molars 
are  as  easily  matched  as  the  simple  labial  cavities,  for  they  come  under 
the  same  conditions  of  light  reflection  ;  but  all  approximal  inlays,  from 
the  posterior  surface  of  the  canines  back  to  the  molars,  show  the  same 
falling  off  in  color,  and  unless  allowance  be  made  for  this  falling  off 
disheartening  results  will  be  the  outcome  of  otherwise  careful  work. 
The  greater  the  slope  of  the  cavity  floor  into  the  month  the  greater 
will  be  the  shadow  variations,  as  in  Fig.  374 ;  the  greater  the  slope  out- 
ward the  less  will  be  the  shadow  variations. 


388  RESTORATION   OF  TEETH  BY  CEMENTED  INLAYS. 

Those  not  aifeoted  are  simple  labial  cavities,  corners  of  centrals  and 
laterals,  cusps  of  canines,  bicuspids,  and  molars. 

Those  most  affected  are  tips  of  centrals  and  of  lateral  incisors,  and 
approximal  and  halfmoou-sliaped  cavities  running  through  the  palatal 
enamel.  The  broader  the  adjacent  teeth  the  greater  will  be  the  shutting 
out  of  light  and  the  consequent  darkening  of  color.  Tips  of  central  and 
lateral  incisors  running  entirely  across  the  tooth  are  so  subject  to  the 
shadow  variations  from  cross  light,  side  light,  top  light,  and  bottom 
light,  that  the  restoration  of  more  than  a  third  is  not  advisable.  When 
half  of  a  tooth  has  been  carefully  matched  and  cemented  into  place,  the 
tip  may  look  very  well  in  good  daylight,  but  at  night  it  may  turn 
dark ;  also  in  an  artificial  light  shining  from  above  the  tooth  and 
cement  line  show  very  dark  while  the  porcelain  seems  snow-white.  In 
all  such  cases,  whenever  possible,  a  portion  of  the  tooth  should  be 
allowed  to  run  down  to  the  cutting  edge. 

And  now  let  ns  consider  how  we  may  partly  conquer  these  shadow 
variations.  Halfmoon-shaped  cavities,  as  in  Figs.  368  and  309,  may  be 
filled  on  the  palatal  wall  with  gold,  an  absolute  match  thus  being  made 
possible.  A  porcelain  tip  may  be  built  up  as  two  corners,  to  avoid  the 
side  lights  ;  but  generally  all  attempts  to  antagonize  shadow  variations 
will  result  in  an  effort  to  lighten  the  fillings,  so  that  the  shadows 
will  be  overcome.  This  lightening  is  now  quite  possible,  for  experi- 
ments indicate  that  an  addition  of  from  one-tenth  to  one-fifth  of  oxid 
of  tin  to  the  ordinary  white  enamel  gives  a  white  so  dense  as  to  be 
practically  the  reverse  of  shadow.  If,  therefore,  we  have  a  filling  half- 
moon-shaped or  approximal,  we  should  first  match  the  porcelain  tooth 
as  though  it  were  a  simple  labial  cavity ;  then  by  adding  to  this  paste 
one-fourth  to  one-third  of  the  dense  white  powder  mentioned  above 
we  shall  find  that,  if  the  colors  have  been  properly  mixed,  the  filling 
when  cemented  into  place  will  darken  to  the  original  color  of  the  tooth. 

And  now  having  described  the  process  of  using  high-fusing  porce- 
lain for  inlays,  the  next  consideration  will  be  the  modifications  necessary 
when  the  low-fusing  porcelain  is  melted  in  a  gold  matrix.  The  best 
of  the  low-fusing  bodies  are  said  to  keep  their  color  and  texture  in  the 
mouth  indefinitely,  to  be  strong  enough  for  all  necessary  wear,  and  to 
retain  their  color  in  fusing, — which  would  indicate  that  the  low-fusing 
materials  have  greatly  improved  during  the  last  eight  or  ten  years. 
Porcelains  capable  of  being  melted  in  a  gold  matrix  are  of  two  classes: 
those  that  are  sufficiently  low  fusing  to  be  melted  in  a  bare  matrix,  and 
those  that  melt  so  near  the  fusing-point  of  gold  as  to  render  necessary 
the  investment  of  the  gold  matrix  in  order  to  prevent  its  being  war])ed 
by  the  fire.  In  porcelains  of  the  first  class  the  method  of  procedure  is 
very  similar  to  that  in  which  the  high-fusing  porcelains  are  fused  in  a 


THE  PORCELAIN  INLAY.  389 

platinum  matrix.  The  No.  30  gold  foil  is  placed  over  the  cavity  mar- 
gins in  a  manner  similar  to  that  prescribed  for  the  use  of  platinum  ;  and 
then,  instead  of  burnishing  or  spinning  it  in  place,  it  is  pressed  into 
all  parts  of  the  cavity  by  means  of  spunk  or  cotton.  The  metal  is  so 
soft  and  ductile  that  this  can  be  accomplished  in  a  manner  impossible 
with  platinum  ;  and  it  is  this  easy  manipulation  of  the  gold  that  makes 
the  sole  advantage  of  the  low-fusing  over  the  high-fusing  porcelain 
bodies.  The  gold  matrix  is  then  teased  out  of  the  cavity.  This  must 
be  carefully  done,  as,  being  more  easily  adapted,  it  is  also  more  easily 
distorted  than  the  platinum.  The  proper  mixture  of  porcelain  is  placed 
in  it,  and  the  baking  is  performed  exactly  as  with  the  high-fusing 
materials,  the  only  marked  difference  in  the  working  of  the  low-fusing 

Fig.  370.  Fig.  371. 


Large  cavity  in  molar  tooth  involving  appniximal  and         Showing  restoration  of  broken  lateral 
grinding  surfaces.    Restored  by  porcelain  inlay.  incisor  by  porcelain  tip. 

and  the  high-fusing  materials  being  that  low-fusing  bodies  tend  to 
spheroid  and  lose  contour.  This  can  be  remedied  by  mixing  with  the 
paste  a  small  quantity  of  similarly  colored  high-fusing  porcelain. 

When  such  porcelains  are  used  as  require  the  gold  matrix  to  be 
invested,  the  following  additional  points  should  be  carefully  observed  : 
The  matrix  must  not  be  torn  on  the  bottom  at  all,  as  in  such  event  the 
porcelain  will  tend  to  run  through  into  the  investment  instead  of  draw- 
ing away  from  the  crack,  as  it  does  from  a  platinum  matrix  where  no 
investment  is  used.  The  gold  matrix  must  be  dropped  bottom  side 
down  into  a  paste  of  asbestos  and  alcohol,  which  is  allowed  to  evaporate. 
Then  the  porcelain  may  be  flowed  into  the  matrix  little  by  little,  to 
minimize  warping. 

The  method  described  by  Dr.  J.  Leon  Williams^  is  as  follows  : 
"  The  thinner  the  gold  can  be  used,  the  more  perfect  the  fit  of  the 
finished  inlay.  A  proper  set  of  instruments  for  shaping  the  gold  form 
and  for  manipulating  the  porcelain  paste  is  an  important  matter.  I 
have  devised  for  these  purposes  the  set  of  instruments  shown  in  Fig. 
372.  They  are  all  double-end  instruments.  Nos.  1,  2,  3,  and  4  are 
designed  for  fitting  the  gold  form  to  the  cavity,  while  Nos.  5  and  6  are 
for  manipulating  the  porcelain  paste.  The  gold  should  be  cut  out  to 
represent  roughly  the  shape  of  the  orifice  of  the  cavity,  but  consider- 
^  Dental  Cosmos,  November  1899,  vol.  xli.  p.  1087. 


390 


RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS. 


ably  larger.     Fig.  373  shows  the  proper  sliape  for  such  a  cavity  as  is 
shown  in  Fig.  374  at  a.     It  will  greatly  facilitate  the  shaping  of  the  gold 


Fig.  372. 


form  if  a  notch  be  cut  out  of  the  gold  as  shown  in  Fig. 
373,  and  at  the  same  time  decrease  the  chances  of  break- 
ing through  the  gold  in  forcing  it  into  the  shape  of  the 
cavity.  It  should  first  be  introduced  into  the  cavity  with- 
out annealing.  The  cut  edges  will  then  slide  over  each 
other  as  the  centre  of  the  gold  is  forced  to  the  bottom  of  the 
cavity.  .  .  .  Then,  with  the  cotton  or  spunk  tightly  packed 
in  the  cavity,  take  instrument  No.  2  and  most  carefully 
burnish  the  gold  around  the  entire  edge  of  the  cavity.  This, 


THE  PORCELAIN  INLAY. 


391 


instrument  will  be  found  well  adapted  to  reach  every  part  of  the  margin. 
It  will  generally  be  found  best  to  hold  the  cotton-wool  back  a  little 
from  the  margin  of  the  cavity  when  one  is  burnishing,  with  an  instru- 
ment held  in  the  left  hand,  and  with  this  instrument  (preferably  a  ball 
burnisher)  also  press  the  cotton-wool  well  into  the  cavity.  This  holds 
the  gold  form  well  in  place  and  prevents  rocking  while  the  edges  are 
being  burnished. 

"  Most  operators  have  found  the  removal  and  imbedding  of  the  gold 
form  to  require  the  most  delicate  manipulation,  and  by  the  methods 
heretofore  described  one  is  never  quite  certain  whether  or  not  this  part 
of  the  operation  has  been  successfully  performed  until  the  inlay  has 
been  completed  and  tried  in  place.  All  of  this  uncertainty  may  be 
avoided  by  the  following  procedure  :  Slightly  warm  and  roll  up  in  the 
fingers  a  small  ball  or  pledget  of  hard  white  wax,  such  as  is  supplied 
for  crown-  and  bridge-work.  The  ball  of  wax  should  be  just  a  little 
larger  than  is  necessary  to  fill  the  cavity  completely;  that  is  to  say,  it 
should  slightly  project  over  the  margin  of  the  cavity  all  round.  The 
wax  should  be  quite  stiff  when  introduced  into  the  gold  form  as  it  lies 
in  the  cavity  of  the  tooth.     Now  take  the  broad,  thin  burnisher,  shown 


Fig.  373. 


Fig.  374. 


Sheet  of  gold  or  plat- 
inum, notched  and 
ready  for  adaptation 
to  cavity. 


Right  superior  central,  showing  two  large  approximal  cavities 
to  which  access  is  obtained  by  cutting  freely  from  the  lin- 
gual walls :  a,  tooth  with  cavities  prepared ;  b,  porcelain 
inlays  for  same;  c,  tooth  showing  lingual  surface;  and  d, 
labial  surface  after  cementing  of  inlays. 


in  No.  4,  Fig.  372,  and  press  the  ball  of  wax  firmly  into  place.  To  pre- 
vent the  burnisher  from  sticking  to  the  wax,  it  should  first  be  dipped 
into  French  chalk  or  pulverized  soapstone.  In  such  cavities  as  are 
shown  in  Fig.  374,  at  (i,  broad  polishing  tape,  dusted  with  French 
chalk,  may  be  used  for  pressing  the  wax  ball  into  place  ;  but  great  care 
should  be  exercised  not  to  pull  the  tape  the  least  in  one  direction  or  the 
other,  as  one  would  do  in  polishing  a  filling.  This  would  rock  the  gold 
form  and  mar  the  fit.  The  pull  should  be  steadily  and  equably  from 
both  ends  of  the  tape,  the  object  being  to  press  the  wax  everywhere 
firmly  over  the  edges  of  the  cavity.  A  stream  of  cold  water  should 
now  be  thrown  on  the  wax,  and  then  the  wax  and  gold  form  should 
be  quickly  removed.     If  this  part  of  the  operation  is  done  with  ordinary 


392 


RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS. 


care,  the  finished  inlay  will  always  be  found  to  fit  perfectly.  To  facili- 
tate the  quick  removal  of  the  form,  care  should  be  taken  to  prevent 
the  wax  overlapping  the  gold  much  at  any  point  outside  the  margin  of 
the  cavitv.  To  prevent  this  and  also  to  assist  in  securing  proper  imbed- 
ding of  the  gold  matrix  it  is  well  to  let  the  margin  of  the  gold  project 
as  much  as  possible  beyond  the  edges  of  the  cavity. 

"  The  matrix  may  now  be  imbedded  without  the  slightest  fear  that 
its  shape  Avill  be  changed.  For  imbedding  material  I  use  plaster  and 
marble-dust.  When  the  investment  is  sufficiently  hard  the  wax  is  thor- 
oughly melted  out  with  a  stream  of  boiling  water.  The  investment  is 
then  dried  and  brought  to  a  full  red  heat  wdth  the  blowpipe.  It 
is  then  allowed  to  cool,  and  is  ready  for  packing.  Xow.  the  first  step 
in  the  packing  of  the  porcelain  paste  is  the  all-important  one  to  prevent 
the  porcelain  shrinking  away  from  the  walls  of  the  matrix.  This  may 
always  be  accomplished  easily  with  porcelain  of  any  make  if  the  follow- 
ing instructions  are  carefully  observed  :  Mix  the  porcelain  paste  to  the 
consistence  of  soft  putty,  and  with  the  upper  point  shown  in  Xo.  6,  Fig. 
372,  place  a  ring  of  this  putty  around  the  entire  circumference  of  the  cavity, 

Fig.  375.  Fig.  376, 


Showing  bicuspid  with  cavity  involving  approxi-  Canine  tooth  showing  at  a,  large  cavity,  and 

mal  and  grinding  surfaces:    o,  tooth  with  at  6  and  c,  large  porcelain  inlay  restor- 

cavity  prepared  ;  b,  porcelain  inlay  ;  c,  inlay  ing  contour  of  tooth, 
cemented  in  place. 

leaving  the  centre  quite  free  or  empty.     In  melting  a  porcelain  paste  it 

naturally  shrinks  toward  the  largest  mass  of  its  own  body,  or  toward 

the  centre  of  the  mass.     If,  then,  this  centre  be  removed  we  should 

naturally  expect  the  mass  to  shrink  toivard  the  circumference,  and  this  is 

precisely  w'hat   happens  wdien   manipulated  as  directed.       The  matrix 

always  comes  out  from  the  first  baking  with  the  porcelain  everywhere 

firmly  melted  to  the  walls  of  the  matrix.     Xor  will  it  start  from  this 

position  at  any  subsequent  leaking  unless  it  is  very  much  overheated. 

"After  each  packing  of  the  porcelain  paste,  a  small  camel's-hair  brush 

with  a  fine  point  should  be  moistened  (this  is  best  done  by  drawing  it 

between  the  lips  after  the  manner   of  water-color  artist.s)   and  di*awn 

around  the  margin  of  the  matrix  to  remove  all  overhanging  particles  of 

the  paste.     If  this  be  not  done,  the  margins  of  the  inlay  will  often  be 

found  ragged,  and  a   perfect  margin  is  the  most  essential  feature  of  a 


THE  PORCELAIN  INLAY.  393 

porcelain  inlay.  If  gum-water  be  used  for  mixing  the  paste,  it  will  be 
found  necessary  to  remove  these  overhanging  particles  with  great  care, 
as  the  tendency  naturally  is  for  the  gum-water  to  cause  the  particles  of 
powdered  porcelain  to  stick  to  the  gold  or  platinum  margin  of  the  ma- 
trix. In  building  up  the  inlay  for  restoring  lost  corners  of  teeth  and  for 
general  contours  the  work  will  be  much  facilitated  if,  after  the  first 
baking  has  been  carried  through  as  above  described,  to  secure  perfect 
union  with  the  walls  of  the  matrix,  a  small  piece  of  solid  porcelain  be 
placed  at  the  point  representing  the  highest  point  of  the  contour  of  the 
inlav.  These  pieces  of  porcelain  may  be  made  by  crushing  old  porce- 
lain teeth  in  an  iron  mortar.  Care  should  be  taken  to  use  a  piece  small 
enough  so  that  the  outer  edge  will  not  show  through  when  the  inlay  is 
completed.  Corners  like  the  one  shown  in  Fig.  376  may  be  produced 
in  this  manner  without  much  difficulty." 

Dr.  Williams's  method  of  separating  the  gold  matrix  from  the  porce- 
lain, and  grooving  the  inlay  and  cementing  it  into  the  cavity,  need  not 
be  dwelt  upon,  the  subject  having  already  been  fully  discussed. 

In  summing  up  the  advantages  and  disadvantages  of  the  high-fusing 
and  low-fusing  bodies  it  will  be  seen  that  the  advocates  of  the  low-fusing 
materials  claim  the  sole  point  that  gold  is  more  easily  adapted  as  a 
matrix  than  platinum  ;  while  the  others  claim  that  porcelains  of  high- 
fusing  bodies  are  known  to  be  permanent,  to  keep  their  color  under 
firing,  to  contour  without  spheroidal  tendency,  to  dispense  with  the 
use  and  consequent  restrictions  of  an  investment,  and  to  furnish  a 
process  so  simple  and  reliable  that  fillings  may  be  constructed  with 
greater  certainty  of  good  results  and  with  more  rapidity. 

Furnaces  suitable  for  fusing  the  porcelains  used  in  inlays  are  of 
two  classes — gas  and  electric.  The  gas  furnace  is  usually  noisy,  odor- 
ous, and  dirty  ;  but  it  seldom,  if  ever,  gets  out  of  order.  On  the  other 
hand,  the  electric  furnace  is  clean,  silent,  and  beautiful ;  but  it  has  only 
a  limited  life.  Even  in  experienced  hands  its  wires  will  burn  out 
and  need  mending  once  or  twice  a  year,  and  with  the  inexperienced  it 
may  easily  be  rendered  useless  in  a  few  seconds.  Nevertheless,  in 
spite  of  these  drawbacks,  the  electric  furnace  is  to  be  preferred  to  the 
gas,  as  with  a  little  practice  it  can  be  easily  mended,  while  the  gas  furnace 
is  suitable  only  for  the  laboratory.  The  only  feasible  gas  furnaces  for 
high-fusing  bodies  are  those  which  have  a  platinum  muffle,  in  which  the 
fusing  porcelain  can  be  thoroughly  protected  from  the  gas,  for  no  fusing 
porcelain  can  keep  its  color  if  subjected  to  the  products  of  combustion 
of  carbon.  The  two  most  practicable  gas  furnaces  are  the  Downie 
(Fig.  377)  and  the  Midget  Land.  Either  of  these  properly  manipu- 
lated will  fuse  continuous-gum  body  within  three  minutes.  They 
w^ork  on   the  blowpipe    principle,  and  necessitate   either    a  pressure- 


394 


RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS. 


reservoir  or  labor  with  the  foot-bellows.  The  electric  furnaces  arc  based 
on  the  principle  that  platinum  wire  submerged  in  fire-clay  will  become 
red-hot  when  a  current  is  passed  through  it.  The  fire-clay  stores  up 
this  heat  indefinitely,  so  that  any  degree  of  temperature  below  the  fusing- 
point  of  platinum  may  be  obtained.  This  fusing-point  is  said  to  be 
about  4500°  Fahrenheit.  The  best  of  these  furnaces  for  the  high-fusing 
bodies  that  require  a  temperature  of  from  2500°  to  3000°  F.  are  the 
Timme  (Fig.  379),  the  Custer  crown  (Fig.  378),  and  the  McBriar  crown. 

Fk;.  .-^77. 


Downie  gas  crown  furnace. 

Any  one  of  these  will  give  satisfactory  results,  but  the  Timme  furnace 
has  the  important  advantage  of  being  made  in  sections  which  can  be 
readily  taken  apart,  thus  rendering  a  burn-out  easy  to  locate  and  mend. 
With  the  other  furnaces  it  is  difficult  at  times  to  find  and  twist  together 
the  fused  or  broken  wires ;  and  when  the  break  is  located,  it  has  to 
be  reached  by  cutting  down  through  fused  fire-clay  that  is  sometimes 
so  dense  as  to  require  the  use  of  a  hammer.  Should  electric  furnaces 
be  used,  it  is  well  to  have  two,  so  that  if  a  burn-out  occur  the  opera- 
tion need  not  be  delayed  while  the  defect  is  being  located  and  repaired. 


THE  PORCELAIN  lyLAY. 

Fig.  378. 


395 


Custer  electric  oven  No.  1. 
Fig.  379. 


Timme  furnace. 


For  baking  the  low-fusino-  bodies  the  gas  outfit  of  Dr.  Jenkins  is 
neat  and  effective  ;  in  fact,  as  a  gas  outfit  it  is  ahuost  ideal.     The  little 


396 


RESTORATION  OF   TEETH  BY  CEMENTED   INLAYS. 


electric  oven  made  by  Ash  (Fig.  380)  is  perfect  for  low-fusing  bodies, 
and  wherever  a  current  can  be  secured  and  low-fusing  l)odies  are  used 
this  little  furnace  is  to  be  strongly  recommended.  Its  only  drawback 
is  that  it  cannot  be  mended,  and  that  if  a  burn-out  occur  it  must  be 


Fj(;.  380. 


Ash  electric  oven. 


sent  to  the  manufacturer  for  a  nev/  coil  of  wire.  It  has  not  sufficient 
power  to  melt  the  high-fusing  bodies  quickly  and  well. 

The  Gold  Inlay. — As  previously  said,  the  gold  inlay  has  practi- 
cally perfect  edge  strength,  and  therefore  is  to  be  preferred  to  the 
porcelain  inlay  in  the  back  of  the  mouth,  where  its  color  is  no  objection 
and  where  its  power  of  resisting  mastication  is  of  prime  importance. 

The  following  method  of  making  gold  inlays  is  the  one  advocated  by 
Dr.  W.  V.  B.  Ames,  of  Chicago  : 

"The  gold  inlay  is  especially  useful  in  compound  approximal  cavities 
of  bicuspids  and  molars.  There  must  be  ample  separation.  As  in  the 
case  of  porcelain,  there  should  be  excavation,  both  to  prevent  decay  and 
to  permit  the  easy  removal  of  the  matrix. 

"Taking,  for  example,  an  occluso-approximal  cavity  of  a  soft  molar 
or  bicuspid  where  a  gold  or  amalgam  filling  has  failed  :  in  such  a  case 
decay  has  usually  extended  laterally,  one  side  or  both,  necessitating 
the  cutting  away  of  the  side  walls  to  such  an  extent  as  to  leave  very 


GOLD  INLAYS. 


397 


little  support  for  the  filling  at  the  cervical  margin.  The  fissure  of 
the  occlusal  surface  must  then  be  opened  thoroughly  to  the  end  for 
anchorage,  and  the  entire  margins  of  the  cavity  be  excavated  until  they 
are  strong,  smooth,  and  sharp.  When  practicable,  an  impression  of 
the  cavity  may  be  taken  in  modeling  compound  and  run  out  in  plaster 
or  oxyphosphate  of  zinc.  To  this  the  matrix,  made  of  pure  gold  Xo. 
36  B.  &  S.  gauge,  can  be  a})proximately  fitted  and  trimmed,  avoiding 
much  laceration  to  the  gum.  The  matrix  should  be,  however,  finally 
burnished  to  fit  the  tooth   cavity.     Then   22-carat  gold  solder  should 


Fig.  381. 


Fig.  382. 


Fig.  383. 


Fig.  384. 


be  flowed  into  the  hollows  of  the  occlusal  surface,  running  otf  into 
the  fissure.  A  coating  of  whiting  placed  on  the  outside  of  the  matrix 
will  prevent  the  solder  from  running  over  the  edge  and  destroying  the 
fit.  Then  it  must  be  cooled,  washed,  and  replaced  in  the  cavity  for 
further  iMirnishing.  When  the  occlusal  groove  is  nearly  full  of  solder, 
a  small  globule  of  pure  gold  should  be  placed,  as  in  Fig.  381,  A,  to  serve 
as  a  guide  for  the  contour,  which  must  be  shaped  up  about  the  pellet 
with  crvstal  gold  or  foil,  into  the  interstices  of  which  22-carat  solder 
is  to  be  again  flowed. 

"  In  the  efforts  to  ol)tain  anchorage  on  the  occlusal  surface  punctures 
or  tears  frequently  occur.  Gold  foil  can  be  inserted  into  these,  which 
when  filled  with  solder  afford  excellent  retain- 
ing pins  (see  c,  Figs.  383  and  385). 

'"Where  sufficient  anchorage  is  easily  ob- 
tained, as  in  pulpless  bicuspids  and  molars,  a 
dowel  or  small  gold  bead  may  be  soldered  to 
the  gold  foil,  and  adjusted  to  the  pulp  cavity,  when  the  first  start  in  the 
formation  of  the  matrix  is  made,  as  in  d.  Figs.  384  and  385.'' 

Some  dentists  restore  the  tips  of  abraded  fn  nt  teeth  by  burnishing 
pure  gold  over  the  surface,  running  little  dowels  up  on  each  side,  so  as 
to  avoid  the  pulp  chamber,  and  finally  moulding  the  contour  with  22- 
carat  solder,  gold  foil,  and  spongy  platinum. 


Fig.  385. 


398 


RESTORATION  OF  TEETH  BY  CEMENTED  INLAYS. 


Dr.  C.  L.  Alexander's  method '  is  described  by  its  author  as  fol- 
lows: "  My  method  consists  in  detail  of  burnishing  platinum  over  the 
surface  to  be  restored;  the  holes  for  retaining  posts  having  already  been 
made,  can  easily  be  located  and  the  posts  adjusted  therein.     Then  by 


Fig.  386. 


showing  details  of  the  process  fi)r  making  cast  tilling  for  incisor:  a,  post  with  plate  adapted; 
B,  restored  contour  in  wax ;  c,  the  contour  invested ;  D,  cast  contour  detached ;  e,  e,  the 
finished  restoration. 

heating  a  little  modeling  compound  over  a  spirit  lamp,  and  })ressing  it 
firmly  down  over  the  surface  and  allowing  it  to  cool,  we  can  remove  the 
platinum  sheet  and  posts  in  correct  relation  to  each  other.  We  now 
invest  and  solder  the  posts  with  pure  gold.  The  piece  is  again  placed 
upon  the  tooth  in  the  mouth,  and  after  carefully  trimming  and  rebur- 
nishing  an   impression  is   taken,  and   when   an  occlusion  is  needed  it 


Fig.  387. 


Fig.  388. 


Restoration  of  bicuspid 
by  cast  filling. 


Front  and  back  view  of  an  incisor  restoration,  and  cast 
filling  for  molar. 


is  made  at  the  same  time  by  the  patient  closing  the  teeth  together 
before  the  impression  material  has  become  hard.  The  metal  founda- 
tion will  be  drawn  out  by  the  impression  compound  when  it  is  removed 
from  the  mouth.  Each  side  of  the  impression  thus  secured  is  filled 
with  any  good  investing  material  and  placed  in  an  articulator.  After 
heating  and  removing  the  impression  material,  the  contour  of  the  tooth 
may  be  restored  by  building  up  with  wax.  Over  the  wax  surface  thus 
^  Dental  Cosmos,  October  1896,  vol.  xxxviii.  p.  850. 


GOLD  INLAY— A  HARD-RUBBER  INLAY. 


399 


formed  gold  or  platinum  foil  is  burnished;  if  the  former,  it  should  be 
very  heavy,  say  No.  60.  A  suitable  portion  of  the  wax  being  left 
uncovered,  the  work  is  cut  away  from  the  model  and  invested,  with  the 
exception  of  that  part  of  the  wax  left  uncovered  by  the  metal.  Through 
this  opening  the  wax  is  boiled  out,  leaving  a  matrix  lined  with  metal, 
which  acts  as  a  carrier  for  the  fused  gold  ;  20-  or  22-carat  gold  solder 
should  be  used  for  this  purpose.  When  pure  gold  is  used,  of  course 
the  matrix  must  be  lined  with  platinum  throughout.  When  removed 
from  the  investment,  the  casting  is  finished  and  cemented  to  its  position 
in  the  tooth. 

"  In  bicuspids  and  molars  it  will  frequently  be  found  more  con- 
venient to  stamp  up  the  cusps,  using  pure  gold,  35  gauge." 

The  pieces  made  as  described  by  Dr.  Alexander  may  be  used  as 
abutments   for   bridge-work.     The   gold   inlays  are,   of  course,  to  be 

Fig.  389. 


Foil  matrix  invested.    Cast  filling  for  molar. 


cemented  into  place  with  great  care  as  regards  asepsis,  dryness,  and 
apposition.  They  have  a  great  advantage  over  the  porcelain  inlays  in 
that  their  edges  may  be  burnished  into  place  while  the  cement  is  soft; 
and  therefore  when  thev  are  being  given  their  final  polish  with  the 
sandpaper  disk  the  disk  should  always  be  run  toward  the  margins,  so 
that  a  feather  edge  may  be  formed,  which,  with  the  burnishing  men- 
tioned, may  make  an  almost  absolute  joint  possible. 

A  Hard-Rubber  Inlay. — Some  dentists  advocate  making  cemented 
inlays  of  hard  rubber  approximating  the  tooth  in  color.  These  inlays 
are  feasible  only  where  a  perfect  impression  can  be  readily  taken  of  the 
cavity,  the  filling  being  then  made  by  the  method  usually  followed  in 
vulcanite  work.  The  rubber  inlay  is  noted  only  as  a  curious  fact,  and 
is  not  enlarged  upon  or  recommended,  as  its  color  is  not  equal  to  porce- 
lain, nor  is  its  edge  strength  equal  to  that  of  gold.  As  we  have  not 
only  other  materials  that  will  produce  better  results,  but  also  materials 
that  can  be  manipulated  in  the  time  required  merely  for  the  vulcanizing 
of  the  rubber,  it  does  not  seem  advisable  to  enlarge  upon  a  process  that 
appears  to  have  no  practical  value. 


400  RESTORATION  OF  TEETH  BY  CEMENTED   INLAYS. 

MAKING    MATRICES    UPON    MODELS    FOR    PORCELAIN    INLAYS. 

There  are  many  wlio  take  impressions  of  the  cavities  intended  for 
porcchiin  inlays,  which  impressions  are  run  out  in  plaster  or  oxyphos- 
})liate  of  zinc.  On  the  models  thus  obtained  the  matrices  are  formed, 
and  the  porcelain  fillings  finished  according  to  shades  selected  when  the 
impression  was  taken.  This  has  the  advantage  of  saving  much  time  for 
the  operator,  as  the  work  of  construction  may  be  done  by  an  assistant 
in  the  laboratory.  As  good  results  are  claimed,  the  process  should  be 
given  a  fair  trial ;  but  on  theoretical  grounds  the  expansion  of  the 
plaster,  or  the  contraction  of  the  oxyphosphate  of  zinc^  used  for  the 
mould  would  tend  to  cause  inaccuracy  in  adaptation  of  the  edge. 
Most  inlay  workers  find  it  sufficiently  difficult  to  get  perfect  adaptation 
when  the  matrix  is  burnished  to  sharp  enamel  edges,  and,  except  in 
labial  cavities,  to  get  the  exact  contour.  Also,  the  colors  often  require 
such  nice  calculation  that  an  assistant,  not  having  seen  the  mouth, 
could  hardly  mix  them  satisfactorily.  While  good  results  have  been 
obtained  by  giving  the  matrices  for  filling  to  an  assistant  especially 
trained  in  the  art  of  fusing  and  mixing  the  porcelains,  thus  proving 
that  such  time-saving  methods  are  practicable,  the  average  dentist 
should  not  attempt  the  art  of  inlays  with  the  idea  of  saving  time; 
probably  there  will  always  be  sufficient  factors  for  failure  if  he  works 
directly  from  the  tooth  cavity  and  gives  his  entire  personal  skill  to 
the  completion  of  the  filling.  With  porcelain  inlays  the  question  of 
artistic  color  eifect  is  paramount,  and  only  through  the  most  subtle 
discrimination  can  the  best  results  be  obtained. 

^  Wet  oxyphospliate  of  zinc  usually  expands;  dry  oxyphosphate  usually  contracts. 


CHAPTER    XVI. 

THE  CONSERVATIVE  TREATMENT  OF  THE  DENTAL  PULP— 
DEVITALIZATION  AND  EXTIRPATION  OF  THE  PULP. 

By  Louis  Jack,  D.  D.  S. 


As  the  dental  pulp  by  its  supply  of  nutritive  pabulum  maintains 
the  vitality  of  the  dentin  and  increases  the  resisting  power  of  the  tooth, 
it  is  important  when  this  organ  becomes  exposed  to  agencies  which 
threaten  its  destruction,  to  attempt  its  preservation  when  the  condi- 
tions are  favorable  to  that  object.  A  further  reason  for  maintaining 
the  vitality  of  the  dentin  is  that  when  the  pulp  becomes  devitalized  the 
loss  of  cohesive  force  which  occurs  as  a  consequence  leads  sooner  or 
later  to  the  fracture  and  early  loss  of  the  tooth — this  final  result  being 
delayed  in  proportion  to  the  inherent  strength  of  the  tooth  and  the 
period  of  life  at  which  devitalization  takes  place. 

The  treatment  of  teeth  when  the  pulp  has  been  approximately 
reached  by  the  invasion  of  dental  caries  has  been  previously  consid- 
ered (Chapter  VII.).  Here  will  be  set  forth  a  rational  line  of  treatment 
when  the  carious  action  has  encroached  upon  that  organ. 

Normal  Characteristics  and    Pathological   Tendencies  op 

THE  Dental  Pulp. 

The  minute  anatomical  elements  of  the  dental  pulp  are  given  in 
■Chapters  II.  and  III.  The  salient  features  of  these  elements  which 
have  to  be  kept  in  view  in  connection  with  treatment  are — 

(1)  The  minuteness  of  the  apical  foramina,  which  restricts  the  efferent 
circulation  when  the  vascular  phenomenon  known  as  '•'  determination  " 
occurs. 

(2)  The  ultimate  nervous  distribution  immediately  beneath  the  odon- 
toblastic layer,  forming  a  plexus  which  renders  the  whole  surface  of  the 
organ  highly  sensitive  when  the  blood  supply  is  increased  as  the  effect 
of  irritation. 

(3)  The  arrangement  of  the  capillary  circulation  in  loops  which  arise 
from  the  vertical  vessels.  This  relation  of  the  vessels  lessens  the  tend- 
ency to  inflammatory  diflFusion. 

26  401 


402  CONSERVATIVE  TREATMENT  OF  THE  PULP. 

(4)  The  absence  of  lynn)luitics,  which  deprives  the  pulp  of  the  power 
to  remove  infiammatory  ett'usions  or  to  convey  insoluble  medicaments. 

It  should  be  noted  that  the  pulp  in  a  normal  state  is  not  a  highly 
sensitive  organ,  but  is  rendered  exquisitely  so  by  the  irritation  from 
external  chemical  and  infectious  influences  incident  to  its  ex})osure. 
And  it  is  under  all  conditions  so  extremely  impatient  of  compression 
that  a  severe  sliock  of  that  kind  renders  recuperation  nearly  impossible. 
This  is  pr()l)ably  due  to  the  liability  of  disconnection  of  the  pulp  with 
its  walls  at  some  point  on  account  of  its  feeble  attachment  to  them. 

The  pathological  tendencies  of  the  pulp  under  irritation  are — 

(1)  To  hyperesthesia, 

(2)  To  circumscribed  hyperemia  under  slight  irritation. 

(3)  To  congestion  or  mechanical  hyperemia  under  increased  irrita- 
tion which  terminates  at  length  in  stasis  by  the  restriction  of  the 
circulation. 

(4)  To  proliferation  of  the  deeper  tissues  as  the  result  of  latent  con- 
gestion attended  by  fatty  degeneration  of  cells  and  the  development  of 
dentinal  nodules — pulj)  stones. 

An  important  consideration  connected  with  the  treatment  of  the 
pulp  is  the  indication  presented  by  a  state  of  the  teeth  designated  as 
the  "temperature  sense."  This  is  a  variable  condition  with  different 
individuals,  some  being  able  to  apply  the  coldest  water  in  the  mouth 
and  to  crunch  ice  without  pain,  whilst  others  whose  teeth  are  sound  are 
disturbed  if  cool  water  is  brought  into  direct  contact  with  these  organs. 
When  irritation  of  the  pulp  occurs  the  temperature  sense  is  exaggerated 
in  the  individual  tooth.  This  variation  from  the  normal,  as  determined 
by  a  comparative  test  of  the  sound  teeth,  becomes  an  important  diag- 
nostic indication,  as  will  appear  later. 

A  further  pertinent  consideration  bearing  upon  the  various  condi- 
tions of  the  exposed  ])ulp,  as  shown  by  the  symptomatology,  is  here  in 
place.  It  has  already  been  indicated  that  when  the  exposure  of  the  pulp 
to  irritation  has  been  slight — that  is,  M'here  this  organ  has  been  measur- 
ably protected  from  exterior  influences  by  the  covering  layer  of  incom- 
pletely decalcified  dentin — the  pulp  is  ordinarily  but  slightly  affected. 
When  the  denudation  has  become  complete  and  the  amount  of  pulp 
surface  in  contact  with  the  carious  matter  has  become  considerable, 
and  further,  when  by  the  solution  and  displacement  of  the  carious 
matter  the  influence  of  the  contents  of  the  mouth  is  direct,  the  disturb- 
ances of  the  pulp  become  progressively  increased.  In  the  light  of  pres- 
ent knowledge  of  these  injurious  influences  the  causes  of  their  operation 
must  be  attributed  to  infection  of  the  pulp  by  the  various  minute  organ- 
isms which  have  their  habitat  in  the  mouth.  The  pulp  tissue  becomes 
infected  in  the  degree  to  which  it  is  exposed  and  in  proportion  to  its 


PATHOLOGICAL   TENDENCIES  OF  THE  PULP. 


403 


Fig.  390. 


power  of  resistance  to  the  pathogenic  character  of  these  forms  of  life. 
It  is  axiomatic  that  the  activity  of  inflammatory  processes  is  usually  iu 
proportion  to  the  degree  and  the  kind  of  infection.  Therefore  it  must  be 
held  here  as  elsewhere  in  surgical  procedures  that  the  existence  of  infec- 
tive influences  and  their  control  have  to  be  kept  clearly  in  view. 

This  consideration  enables  us  to  understand  the  causes  which  render 
conservative  treatment  inoperative,  in  cases  in  which  there  has  existed 
'  for  a  considerable  period  the  opportunity  for  active  invasion  of  the  pulp 
by  micro-organisms.  When  these  deleterious  influences  have  long  con- 
tinued, the  deeper  tissues  of  the  pulp,  as  before  stated,  become  involved  ; 
the  chief  factors  producing  the  disturbed  state  eventuate  in  a  suppura- 
tive condition.  This  state  of  the  organ  clearly  indicates  invasion  by  pyo- 
genic germs,  the  inflammatory  processes  attending  this  condition  being 
superinduced  by  the  peculiar  irritation  caused  by  the  infection.  This 
results  in  some  instances  in  stasis  followed  by  gangrene  ;  in  other  cases, 
Avhere  the  arterial  tension  has  not  been  great,  in  suppuration.  The  cha- 
racter of  the  suppurative  process,  rarely,  is  a  circumscribed  abscess  of 
the  pulp,  the  more  common  form  being  by 
progressive  and  destructive  ulceration  of 
the  organ. 

Fig.  390  (after  Arkovy)  shows  the 
phenomenon  of  invasion  of  the  pulp  by 
micrococci.^ 

In  the  treatment  of  an  orphan  which 
cannot  be  brought  under  ocular  inspec- 
tion, the  chief  guides  to  determine  its  state 
are  the  apparent  conditions — viewed  in  con- 
nection with  the  symptomatology  of  the 
case  under  treatment. 

The  above-stated  anatomical  relations, 
physiological  qualities,  and  pathological  tendencies  have  an  interesting 
bearing  upon  conservative  treatment  of  the  pulp. 

Exposure  of  the  Pulp. — As  an  indication  of  the  tolerance  of  the 
pidp  to  the  approach  of  caries  it  is  a  common  experience  that  after 
solution  of  the  enamel  has  taken  place,  caries  of  the  dentin  proceeds 
until  the  pulp  is  nearly  reached  by  the  destructive  process  with  little  or 
no  signs  of  irritation,  as  evinced  by  pain,  appearing.  It  is  the  excep- 
tion that  even  persons  of  high  nervous  sensibility  are  cognizant  of  the 
influence  of  the  carious  process  upon  the  pulp  previous  to  actual 
encroachment. 

In  the  earlier  stages  of  exposure  the  elements  of  the  organ  involved 

^  In  this  connection  see  Micro-organisms  of  the  Human  Mouth,  by  W.  D.  Miller,  pp.. 
293-295. 


Invasion  of  pulp  by  micrococci. 


404  CONSERVATIVE  TREATMENT  OF  THE  PULP. 

are  its  peripheral  nerve  filaments,  which  :ire  hyperesthetic  from  the 
hypercmic  state  of  the  organ  immediately  adjacent  to  the  point  of 
encroacinnent.  At  this  stage  the  pulp  becomes  im])atient  of  cold,  and 
may  indicate  the  nature  of  the  lesion  by  reflex  pain  in  other  branches 
of  the  trigeminus.  I^ater  on,  nnless  these  conditions  are  subdued  by 
treatment  congestion  of  the  organ  takes  place,  when  objective  symp- 
toms in  the  organ  itself  may  be  elicited.  This  is  shown  by  some  sore- 
ness upon  percussion,  accompanied  by  much  pain  on  the  application  of 
heat. 

These  indications  point  to  a  greatly  increased  blood  su])[)ly.  Dihi- 
tation  of  the  arterial  vessels  of  the  apical  region  occurs,  and  the  blood 
being  unable  to  enter  at  the  foramen  is  distributed  to  the  peridental 
membrane.  These  manifestations  indicate  that  the  point  of  danger 
has  approached.  Soon  thereafter  congestion  becomes  so  far  estab- 
lished that  prospect  of  successful  conservative  treatment  vanishes. 

When  patients  are  under  frequent  observation  and  have  regular  and 
periodical  care  taken  of  the  teeth  the  pulp  exposui'es  which  occur  should 
be  found  in  the  hyperemic  state,  and  if  ])laced  under  treatment  early 
after  the  carious  action  has  approached  the  pulp,  the  prognosis  should 
be  favorable.  But  when  neglected  cases  appear  the  history  of  which 
is  obscure,  and  where  the  patient  is  forced  to  seek  relief  by  the  occur- 
rence of  objective  symptoms  as  narrated  above,  accompanied  by  local 
pain  and  pulsation,  the  indications  point  to  devitalization  and  extirpa- 
tion as  the  suitable  recourse. 

The  exposure  of  the  pulp  is  often  discovered  in  the  treatment  of 
ordinary  cavities  in  a  somewhat  unexpected  manner,  no  indications 
appearing  nntil  the  part  is  uncovered  ;  or  a  variety  of  subjective  or 
possibly  objective  indications  may  be  elicited  which  plainly  point  to 
this  condition. 

At  the  commencement  of  the  treatment  to  restore  the  lost  tissue 
in  any  given  carious  tooth,  except  in  very  small  cavities,  the  })roba- 
bility  of  encroachment  upon  the  pulp  should  be  a  supposition,  and  each 
step  should  be  made  with  reference  to  this  probability.  The  destruc- 
tion of  the  dentin  is  frequently  surprisingly  deep,  or  the  cornua  of  the 
pulp  may  be  acutely  pointed  and  liable  to  be  unexpectedly  encountered. 
Therefore,  in  what  may  seem  simple  cases,  cautious  approach  should  be 
made  toward  the  bottom  of  the  cavity. 

Method  of  Opening  the  Cavity. 

The  opening  of  the  cavity  should  be  effected  by  instruments 
which  will  not  easily  enter  it,  and  the  softer  caries  removed  in  a 
manner  which  will  not  induce  pressure  of  the  carious  matter  upon  the 
pulp.     For  this  reason,  in  the  removal  of  the  caries  the  excavation 


METHOD   OF  OPENING    THE  CAVITY.  405 

should  be  first  carried  on  at  the  sides  of  the  cavity,  and  also  along  the 
margin  of  the  cervical  wall  in  approximal  cases.  Then  the  carious 
matter  nearest  the  pulp  should  be  carefully  peeled  oif  without  pres- 
sure and  without  irritation.  In  this  manner  a  pulp  may  be  uncov- 
ered and  the  cavity  cleansed  of  carious  matter  w^ithout  contact  being 
made  with  the  pulp.     To  do  this  is  the  acme  of  skilful  preparation. 

The  instruments  for  removing  caries  should  be  of  thin  edge,  very 
■  sharp,  and  always  having  cutting  surfaces  which  are  rounded,  since 
angular  or  square-ended  excavators  are  liable  to  make  exposures  un- 
necessarily. It  is  important  that  the  direction  of  movement  of  the  ex- 
cavators should  be  from  the  cervix  toward  the  occlusal  part — in  other 
words,  by  drawing  cuts  instead  of  pushing  ones.  The  diiference  in  the 
excitement  of  pain  between  these  two  methods  of  cutting  is  surprising, 
and  can  only  be  appreciated  by  those  Avho  have  experienced  the  com- 
parison upon  their  own  teeth.  The  probable  reason  for  this  is  that  the  force 
of  the  pushing  cut  is  necessarily  greater,  and  this  may  induce  com- 
pression of  the  caries  or  of  fluids  against  the  pulp.  It  causes  more 
pain  at  the  moment,  and  cleansing  in  this  manner  is  followed  by  greater 
after-irritation.  Patients  will  at  the  time  complain  of  reflected  pain 
being  caused  by  incorrect  manipulation. 

It  is  obvious  that  every  mode  of  procedure  which  increases  the  local 
irritation  in  the  preliminary  procedures  of  a  pulp  treatment  must  be 
deleterious  in  its  results.  The  danger  of  making  accidental  exposures 
and  of  forcing  the  instruments  upon  the  pulp  are  increased  under  push 
cutting.  It  is  also  clear  that  the  use  of  burring  instruments  upon  the 
pulp  wall  of  cavities  is  questionable,  since  the  infliction  of  some  com- 
pression by  excavating  in  this  manner  is  nearly  unavoidable. 

Here  an  interesting  question  appears  :  A  cavity  may  be  sufficiently 
deep  to  cause  an  exposure ;  it  has  been  carefully  cleansed  of  caries,  and 
the  cornua  are  not  apparent.  It  is  then  necessary  to  determine  whether 
there  is  a  real  but  minute  exposure  or  whether  there  is  a  safe  amount 
of  healthy  dentin  to  protect  the  pulp  beneath  the  stopping  material. 

One  method  is  to  eross-hafcJi  the  cavity  by  a  very  fine  explorer. 
This  is  eifected  by  holding  the  instrument  very  lightly  and  passing 
it  gently  over  the  surface  in  parallel  lines  in  two  directions.  If  the 
pulp  has  been  reached,  the  instrument  at  the  point  of  encroachment 
will  lose  its  resistance  or  will  drag  the  point  of  the  cornu,  as  the  case 
may  be. 

While  there  may  be  no  visual  evidence  of  exposure,  the  certainty  of 
it  is  frequently  shown  during  the  preparation  of  the  cavity  or  the  test- 
ing by  a  peculiar  expression  of  the  face  of  the  patient,  diflerent  from 
that  manifested  by  the  cutting  of  the  most  exquisitely  sensitive  dentin. 
This  change  of  the  countenance,  accompanied  by  a  slight  start  of  the 


406  CONSERVATIVE  TREATMENT  OF  THE  PULP. 

features,  may  occur  without  the  recognition  of  pain.  This  indication 
sometimes  aj)i">ears  previous  to  the  removal  of  all  the  caries;  it  is  then 
pi'obably  caused  by  some  tension  of  the  apex  of  the  cornu  produced 
by  the  disturbance  of  the  carious  dentin. 

The  Diagnostic  Value  of  the  Reaction  of  the  Pulp  to 
Thermal  Tests. 

Allusion  has  been  made  to  the  efFects  caused  by  reducing  the  tem- 
perature of  the  teeth.  To  make  this  subject  clear  it  is  necessary  to  con- 
sider the  reaction  of  the  dental  pulp  to  thermal  changes  in  its  states  of 
health  and  of  disease. 

The  normal  rate  at  which  the  pulp  of  sound  teeth  reacts  to  cold 
applications  varies  with  different  persons  from  22  to  66  degrees  F.  below 
the  blood  heat,  the  reaction  to  heat  varying  from  20  to  over  55  degrees 
F.  above  the  blood  temperature,  these  tests  being  the  extremes  of  the 
writer's  observations. 

The  degree  of  heat  reaction  may  be  designated  by  the  +  sign  and 
the  cold  rate  by  the  —  symbol.  These  ascertained  extremes  may  be 
taken  as  representing  the  ranr/e  of  tolerance  in  any  individual  case. 

The  significance  of  ascertaining  the  normal  rate  of  thermal  irritation 
of  the  teeth  is  important  in  connection  with  the  treatment  of  any  case. 
When  a  healthy  rate  of  +  144°  -  32°  F.  is  compared  with  one  of  +  124° 
—  76°  F.  this  at  once  is  apparent.  In  the  one  case,  the  range  of  tolerance 
is  112  degrees ;  in  the  other,  48  degrees.  Hence  it  is  obvious  that  the 
determination  of  the  normal  rate  is  essential  as  a  basis  from  which  to 
consider  the  value  of  the  thermal  reaction  of  any  given  disturbed  pulp. 
It  is  also  evident  that  where  the  range  of  tolerance  is  considerable  the 
probability  of  favorable  treatment  is  greater  than  when  this  is  small. 
Where  the  normal  range  is  found  to  be  below  50  degrees  F.,  unless  the 
other  conditions  are  very  favorable,  conservative  treatment  of  the  pulp 
becomes  questionable. 

The  normal  rate  is  easiest  found  by  exposing  the  lower  incisors  to  a 
continued  discharge  of  water  from  a  small-aperture  syringe.  The  most 
suitable  kind  of  syringe  is  that  having  a  large  aperture  for  charging 
and  a  small  one  for  discharging.^ 

The  tests  are  begun  at  a  temperature  of  80°  F.,  reduced  succes- 
sively by  diminutions  of  ten  degrees  until  slight  pain  follows  the  tests. 
The  continuation  of  the  stream  of  cold  water  is  necessary  to  enable 
the  effect  to  reach  the  pulp  through  the  dentin.  With  some  per- 
sons the  response  is  so  quickly  shown  as  to  indicate  that  the  dentin 
is  responsive. 

^  The  best  for  the  purpose  is  a  modified  form  of  the  Laskey  syringe. 


REACTION  OF  THE  PULP  TO  THERMAL   TESTS.  407 

A  large  proportion  of  persons  manifest  distress  between  40°  and 
60°  F. 

Intolerance  of  heat  is  determined  in  the  same  manner,  except  that 
it  is  frequently  necessary  to  isolate  the  tooth  by  applying  rubber  dam, 
since  the  gum  usually  begins  to  be  pained  at  130°  F.  In  all  cases  in 
Avhich  the  cementum  is  exposed  isolation  is  required,  since  the  cemen- 
tum  may  react  at  slight  variations  from  blood  heat.  To  secure  exact- 
ness in  any  case  isolation  is  better  than  an  open  test. 

When  disturbance  of  the  pulp  occurs  from  the  extended  progress 
of  caries  the  reaction  of  the  pulp  to  changes  of  temperature  is  usually 
marked,  and  the  variation  from  the  normal  rate  is  indicative  of  the 
degree  of  disorder  of  this  organ.  The  response  occurs  to  temperatures 
both  below  and  above  the  normal  rate.  When  the  irritation  of  the 
pulp  consequent  upon  its  exposure  is  slight,  the  reaction  is  principally 
to  cold,  the  degree  apparently  depending  upon  the  extent  of  the  hyper- 
emia. When  the  reaction  to  heat  is  marked,  congestion  of  the  organ 
is  threatening. 

Disorders  of  the  pulp  appear  to  excite  other  anatomical  elements  of 
the  teeth,  as  is  indicated  by  reaction  to  cold  and  heat  being  more 
immediate  than  is  the  case  with  the  sound  teeth.  A  more  exact 
degree  of  temperature  reaction  may  also  be  secured  when  this  condi- 
tion exists. 

It  is  essential  in  making  tests  that  a  carious  cavity  be  closed  by  a 
pledget  of  wet  cotton.  This  is  sufficient  to  exclude  the  disturbing  effect 
of  the  hypersensitive  dentin,  since  water  is  a  nearly  absolute  non-con- 
ductor. 

Examples  from  practice  to  illustrate  :  1.  Cavity  rate,  +  110°  —  80°, 
when  protected  as  above  +  130°  -  60°.  Here  the  normal  rate  was 
+  131°  -  58°.  2.  Cavity  rate,  +  108°  -  90°  ;  normal  rate,  +  134° 
-65°.     3.  Cavity,  4  120°  -  50°  ;  normal,  128°  -48°. 

The  following  table  of  normal  rates  shows  the  relation  between  the 
point  of  heat  reaction  of  the  pulp  and  the  degree  of  its  reaction  upon 
the  abstraction  of  heat : 


+  152°  —  41° 
+  150°  —  40° 
+  144°  _  48° 
+  144°  —  32° 
-f-  140°  —  48° 
+  140°  —  46° 
+  140°  —  46° 
+  140°  — 32° 
+  140°  — 56° 
+  134°  —  58° 
+  134°  —  65° 
+  134°  —  60° 


+  133°  —  66° 
+  131°  —  63° 
+  130°  —  55° 
+  130°  —  72° 
+  128°  —  48° 
+  126°  —  64° 
+  124°  —  76° 
+  124°  —  60° 
+  122°  —  75° 
+  120°  —72" 
+  118°  — 74° 


408  CONSERVATIVE  TREATMENT  OF  THE  PULP. 

The  normal  averages  of  table — 

9  cases  from  +  152°  to  +  140° 

average  +  143.3°  —  43.2°  =  100°  range  of  tolerance  ; 
7  cases  from  +  140°  to  ^   130° 

average  +  132.3°  —  62.7°  =  69.6°  range  of  tolerance ; 
7  cases  from  +  130°  to  +  118° 

average  +  123°  —  07°  =  56°  range  of  tolerance. 

Occult   Cases  of  Reflected  Pain. 

Cases  difficult  of  diagnosis  sometimes  appear  in  which  the  question 
arises  whether  tlie  pain  is  caused  by  a  hyperesthetic  pulp,  by  tlie  influ- 
ence of  malarial  poisoning,  or  by  a  gouty  condition.  When  the  origin 
depends  upon  the  two  causes  last  named  the  teeth  are  not  subject  to 
thermal  irritation  ;  also  from  these  causes  the  occurrences  of  pain  are 
not  confined  to  the  evening,  as  usually  is  the  case  with  teeth  in  the 
early  stages  of  disturbance. 

The  stages  of  pulp  exposure  are  divisible  into  three  periods — (1)  of 
quiescence  ;   (2)  of  subjective  symptoms,  and  (3)  of  ohjecfive  manifestations. 

(1)  Quiescence  may  continue  in  many  instances  for  a  considerable 
period  after  caries  has  reached  the  pulp  where  the  situation  is  such 
that  the  force  of  mastication  cannot  cause  compression  of  the  contents 
of  the  cavity.  Notwithstanding  constant  saturation  of  the  gelatinous 
covering,  and  the  presence  of  the  micrococci  concei'ued  in  producing 
the  caries  of  the  dentin,  excitement  of  the  pulp  may  not  occur.  The 
fact  should  not  be  overlooked  that  some  persons  escape  odontalgic 
symptoms  notwithstanding  such  progressive  alteration  of  the  pulp  tissue 
takes  place  as  to  result  in  gangrene  of  the  organ. 

(2)  Usually,  however,  after  a  period  of  quiescence  of  a  longer  or  shorter 
duration  there  arises  a  train  of  subjective  disturbances  brought  on  by 
the  continuance  of  chemical  irritation  and  by  the  presence  of  fluids  in 
the  cavity,  these  influences  becoming  accelerated  as  the  area  of  exposure 
becomes  increased.  The  pain  which  occurs  in  this  stage  is  reflected  to 
one  or  more  branches  of  the  fifth  pair  of  nerves.  Flashes  of  pain 
occur  to  the  teeth  of  the  other  maxilla,  to  the  eye,  or  the  supraorbital 
region,  the  most  common  region  affected  being  the  nerves  of  the  ear, 
pain  in  this  organ  being  probably  the  most  general  form  of  reflection 
which  occurs.  The  exacerbations  take  place  usually  in  the  evening  and 
at  first  entirely  remit  in  the  daytime.  The  pain  in  this  stage  will  fre- 
quently pass  away  as  the  pulp  is  relieved  from  pressure  and  chemical 
irritation. 

In  this  stage  the  surface  of  the  pulp  does  not  present  indications  of 
being  inflamed.  From  the  lack  of  continuity  of  the  symptoms  it  is 
a  reasonable  inference  that  the  hyperesthesia  observed  in  this  condition 
is  due  to  impressions  made  upon  the  point  of  encroachment  and  is  con- 


TECHNICAL   TREATMENT  OF  THE   UNCOVERED  PULP.       409 

fined  to  the  nerve  fibrils  distributed  about  the  capillary  loops  involved, 
and  thereby  induces  the  reflected  manifestations,  the  nerve  fibrils  being 
in  this  stage  the  anatomical  element  chiefly  implicated. 

(3)  Objective  symptoms  comprise  those  manifestations  which,  after 
the  subjective  ones  have  continued  for  some  time,  become  localized  in 
and  about  the  aflPected  tooth.  These  are  :  some  soreness  of  the  peri- 
dental membrane;  extreme  sensitiveness  to  heat,  accompanied  through- 
out with  dull,  heavy  pain  in  the  tooth,  and  at  length  pulsat-ive 
throbs. 

This  order  of  statement  is  the  usual  sequence  in  which  these  indica- 
tions appear.  They  are  the  result  of  the  extension  of  the  disturbance 
to  the  deeper  circulatory  elements  of  the  tissue.  When  this  condition 
appears  on  the  presentation  of  a  case,  or  when  in  the  course  of  the 
treatment  it  becomes  apparent,  the  prognosis  usually  is  rendered 
unfavoral)le  to  recui)eration. 

The  Technical  Treatment  of  the  Uncovered  Pulp. 

Accidental  Exposures. — These,  wdiich  happen  in  the  preparation 
of  cavities,  if  ]>roduced  by  clean  (aseptic)  instruments  where  compres- 
sion has  been  avoided,  require  but  simple  treatment.  The  pain  is 
relieved  by  the  application  of  tincture  of  calendula  one  part,  to  four  of 
water.  When  the  bleeding  ceases,  the  point  of  exposure  should  be 
antiseptically  dressed  and  capped  in  the  manner  to  be  described. 

If  the  injury  has  been  slight,  the  cavity  may  be  at  once  filled  with 
a  metal,  having  regard  to  the  strength,  the  placement,  and  the  fixation 
of  the  cap  used  to  defend  the  part  from  compression.  Here  the  fixa- 
tion may  be  made  by  covering  the  cap  with  a  broad  block  of  gold  foil ; 
after  adapting  this  to  the  margins  of  the  pulp  wall  of  the  cavity  the 
filling  may  be  proceeded  with.  In  case  of  doubt  a  metal  of  less  con- 
ductivity may  be  used,  such  as  tin  or  amalgam.  A  metal  filling  is 
better  in  these  cases,  since  the  slight  thermal  irritation  tends  to  the 
ultimate  recovery.     (See  Chapter  VII.) 

Treatment  of  Recent  Exposures. — When  the  pulp  has  been  fully 
uncovered,  as  previously  described,  the  cavity  should  be  w^ashed  clean 
with  tepid  water,  be  securely  protected  from  the  fluids  of  the  mouth 
Avith  rubber  dam,  dried,  and  lightly  filled  with  a  pledget  of  lint  sat- 
urated with  a  mild  disinfectant.  On  account  of  the  invasion  of  the 
zone  of  dentin  immediately  beneath  the  caries  by  bacteria  and  micro- 
cocci, it  is  recognized  that  some  means  of  sterilization  must  be  adopted. 
This  being  necessary  in  the  treatment  of  ordinary  cavities,  it  is  evidently 
here  more  demanded.  On  account  of  the  impatience  of  the  pulp  to 
medication  it  is  important  to  be  careful  in  the  selection  of  the  sterilizing 
agent.     The  choice  should  be  between   hydronaphthol,  acetanilid,  and 


410  CONSERVATIVE  TREATMENT  OF  THE  PULP. 

formalin  :  tlie  first  in  the  strength  of  1  to  .'^OO  parts  water ;  the  second, 
1  to  200  parts  ;  tlie  tliird,  not  stronger  tlian   3  per  cent. 

Tlie  saturated  })ledget  of  cotton  may  remain  in  the  cavity  during  the 
procedures  of  the  preparation  of  the  dressing  paste,  the  selection  of  the 
<iap,  etc. 

When  these  preparations  are  complete  the  cavity  should  be  again 
dried,  the  drying  being  finished  by  a  few  puifs  of  warmed  air.  The 
point  of  exposure  and  the  adjacent  dentin  are  now  touched  with  lint, 
filled  with  carbolic  acid  and  oil  of  cloves,  equal  parts.  The  effect 
of  tliis  is  to  coagulate  to  a  superficial  degree  the  point  of  exposure. 
This  practice  is  largely  empirical.  It  may  be  avoided  in  cases  where 
no  disturbance  has  previously  existed  ;  but  where  there  are  evidences 
of  irritation  it  seems  indispensable. 

The  application  of  carbolic  acid  in  this  manner  should  be  for  a 
moment  only.  As  carbolic  acid  has  a  very  feeble  affinity  for  water  and 
as  the  topical  touch  is  but  momentary,  it  probably  does  not  invade  the 
tissue  to  an  appreciable  degree.  It  will  also  be  observed  that  the  com- 
bination possesses  anesthetic  properties. 

The  student  will  not  fail  to  hold  in  view  that  the  treatment  is  appli- 
cable to  cases  in  which  it  is  evident  the  pnlp  tissue  is  not  under  much 
irritation.  The  condition  should  be  one  of  hyperemia  of  the  organ  and 
gives  indications  of  this  by  the  existing  hyperesthesia.  Congestion 
should  not  have  taken  place,  neither  should  inflammatory  indications 
exist.  Therefore  the  inference  is  that  after  the  carious  matter  is  removed 
the  surface  of  the  dentin  and  the  point  of  exposure  may  be  sterilized 
and  the  vital  force  of  the  pnlp  be  given  the  opportunity  to  overcome 
whatever  slight  bacterial  invasion  may  have  reached  that  organ.  Here 
the  case  must  rest  upon  the  well-established  fact  that  the  tissues  have 
considerable  power  of  mastering  the  influence  of  non-pathogenic  germs 
as  a  factor  in  the  process  of  recuperation. 

Treatment  of  Old  Exposures. — In  the  conditions  which  exist 
where  denudation  has  taken  place  to  a  considerable  degree  and  where 
irritation  has  long  continued,  the  disturbances  which  have  arisen  in 
consequence  of  the  extension  of  the  disorder  to  the  larger  bloodvessels 
and  the  attendant  alteration  of  most  of  the  anatomical  elements  of  the 
pulp,  the  chances  of  establishing  quiescence  are  slight. 

In  the  earliest  stages  of  objective  disturbances  when  the  constitu- 
tional conditions  are  favorable  an  attempt  may  be  made  at  conservative 
treatment  after  the  inflammatory  conditions  are  subdued  by  antiseptic 
treatment,  accompanied  by  the  use  of  resorbents  and  counter-irritation 
upon  the  gum. 


CAPPING   THE  PULP.  411 

Capping  the  Pulp. 

A  prominent  feature  in  the  conservative  treatment  of  the  pulp  is  the 
means  to  protect  it  from  pressure,  in  agreement  with  the  established 
fact  that  there  is  no  irritation  so  fatal  to  the  normal  functions  of  the 
pulp  as  compression,  and  no  condition  from  Avhich  it  recovers  with  so 
much  difficulty  as  this.  Therefore  all  means  directed  toward  its  con- 
servation must  conform  to  the  necessity  of  preventing  the  least  degree 
of  compression.  The  means  employed  to  prevent  this  form  of  disturb- 
ance have  given  this  method  of  treatment  the  common  appellation  of 
^'  capping  the  pulp." 

Another  principle  of  equal  importance  connected  with  the  foregoing 
is  that  the  capping  material  should  be  brought  into  immediate  apposi- 
tion with  the  pulp.  This  is  for  the  reason  that  if  the  least  space  be 
permitted  to  exist  between  the  capping  and  the  exposed  point  this  space 
will  fill  with  eflFused  fluids,  and  the  putrefactive  changes  which  take 
place  in  these  fluids  induce  the  formation  of  gases  with  consequent 
•compression. 

METHOD    OF    CAPPING. 

Various  methods  of  capping  are  practised,  such  as  laying  on  the  part 
■disks  of  paper  or  asbestos  rendered  antiseptic  in  various  ways  ;  using 
disks  of  paper  coated  on  the  side  to  be  placed  next  the  pulp  with 
^^  chloro-percha "  or  other  plastic  matter;  flowing  over  the  exposed 
point  a  coating  of  oxysulfate  or  oxychlorid  of  zinc,  being  careful  with 
the  latter  to  use  a  formula  of  the  fluid  element  in  which  the  zinc 
chlorid  is  only  in  sufficient  proportion  in  relation  with  the  water  that 
the  union  with  the  zinc  oxid  is  not  active.  In  connection  with  this 
method  it  has  been  common  to  mistakenly  employ  the  strength  of  the 
fluid  wliicli  is  used  when  the  formula  is  adapted  for  temporary  fillings. 
When  this  method  is  used  the  coating  is  flowed  over  or  laid  in  a  cap  on 
the  pulp,  and  when  somewhat  "  set "  the  cavity  is  temporarily  filled 
with  a  more  resistant  material  laid  upon  it  with  great  care. 

AVith    all    the    precautions    which    may    be    taken    these   dressings 
are  somewhat  complicated  and  are  not  applicable  to  small  cavities  or 
those  difficult  of  access.     In  these  cases  the 
writer  has  generally  depended  upon  the  use  Fig.  391. 

of  a  dressing  composed  of  carbolic  acid  and 
oil  of  cloves  equal  parts  combined  with  zinc 
oxid   to   form  a  plastic    paste  of  such   consist-         Weston's  dental  cavity  caps. 
ence  that  when  it  is  laid  upon  the  pulp  it  will 

yield  as  it  is  adapted  to  the  part,  without  producing  pressure,  and  will 
flow  out  around  the  margins  of  the  metal  cap  when  this  is  used  to  con- 
vev  the  dressinsj. 


412 


CONSERVATIVE  TREATMENT  OF  THE  PULP. 


The  composition  of  the  dressing  is  based  ujwn  the  considerations 
that  the  nienstrunin  is  antisc])tic,  and  })ossesses  some  anesthetic  value. 
It  also  remains  unchanged  within  the  space  and  in  time  becomes,  from 
the  dissipation  of  the  menstruum,  somewhat  tirm  in  its  character.  The 
therapeutic  action  of  the  menstruum  when  combined  with  the  zinc  oxid 
is  mild,  and  is  employed  for  the  reason  that  it  is  slowly  given  up  by  the 
oxid,  and  therefore  makes  an  acceptable  dressing. 

The  Cap. — In  all  cases  where  metal  fillings  are  selected  it  is  essential 
to  use  a  metal  cap.  The  methods  where  this  is  used  are  simpler  and 
better  under  control  than  when  dressings  are  made  without  this  appli- 
ance. The  reason  for  this  is  that  the  avoidance  of  compression  is  more 
certain. 

The  caps  are  best  when  made  of  platinum,  for  the  reasons  that  this 
metal  is  a  resistant  material  and  the  caps  are  easily  formed. 

AVhen  the  outer  tilling  is  to  be  of  gutta-percha  or  of  the  mineral 
cements,  caps  may  be  formed  of  concave  disks  of  pure  tin.  The  tin 
and  platinum  caps  are  stamped  from  the  plate  by  the  hollow  punches 
of  the  hardware  shops,  by  Avhich  means  various  sizes  of  round  and 
elliptical  ones  may  be  made.  The  effect  of  punching  them  upon  the 
end  of  a  block  of  wood  gives  the  suitable  concavity  to  meet  the  require- 
ments. For  ordinary  purposes  they  should  be  quite  thin,  but  when 
gold  fillings  are  made  over  them  the  thickness  and  the  concavity  should 
be  such  as  to  enable  them  to  sustain  the  force  applied.  In  cases  where 
there  are  indications  of  approaching  congestion,  or  where  it  is  probable 
that  the  exposure  is  not  recent,  the  dressing  should  have  added  to  it  a 
portion  of  guaiacocain. 

Placing  the  Cap  in  Position. — Placing  the  cap  in  position  is  a  step 
in  the  treatment  requiring  care.  It  should  be  assured  that  it  is  of  suf- 
ficient size  to  pass  well  beyond  the  borders  of  the  ex- 
posed organ,  and  in  the  approximal  cavities  it  should. 
cover  the  pulp  wall  of  the  cavity  without  intruding 
upon  the  marginal  walls.  If  there  is  a  single  exposure 
it  should  be  round ;  if  two  cornua  are  exposed,  either 
two  caps  should  be  laid  or  one  oval  one  employed,  as 
may  best  suit  the  case.  In  molars,  usually,  where  two 
points  are  exposed,  two  caps  are  generally  best ;  in  the 
bicuspid,  one  oval  one  under  the  same  circumstances. 
The  cap  should  be  inserted  edgewise  in  such  manner 
that  as  it  is  laid  in  place  the  excess  of  dressing  may  flow 
out  at  the  margin  toward  the  operator.  This  is  to  prevent  undue 
pressure,  and  to  avoid  air  being  included  beneath  the  dressing,  which 
would  prevent  complete  apposition  of  the  dressing  with  the  pulp. 
In  cases  of  easy  access  the  cap  may  be  laid  in  place  with  fine-pointed 


Fig.  392. 


CAPPING   THE  PULP.  413 

pliers — notably  the  Bogiie  pliers  ;  but  in  the  majority  of  instances  it  is 
preferable  to  previously  coat  the  convex  side  of  the  metal  with  wax, 
when,  with  an  instrument  adapted  to  the  case,  it  may  be  carried  into 
position  and  then  placed  in  tlie  manner  described.  It  should  next 
be  pressed  into  position  with  sufficient  force  to  bring  the  margins  in 
contact  with  the  dentin.  Any  excess  of  dressing  should  be  taken  away 
by  light  touches  of  an  excavator,  and  when  the  cavity  is  to  be  filled 
temporarily  it  is  better  to  fix  the  cap  in  place  by  flowing  over  it  a  little 
chloro-pereha,  which,  when  dried,  prevents  disturbance  of  its  position 
in  the  filling  procedure. 

Care  should  be  taken  that  when  the  pulp  is  found  exposed  in  a  de- 
pression, as  occurs  sometimes  in  the  molars,  this  depression  should  be 
filled  nearly  or  quite  to  a  level  with  the  floor  of  the  cavity  by  taking  a 
little  of  the  dressing  upon  a  sviitable  instrument  and  carefully  filling 
this  point  ;  otherwise,  when  the  cap  is  placed,  the  paste  may  not  find  its 
way  into  contact  with  the  ])ulp. 

At  the  moment  of  placing  the  cap,  as  the  paste  is  yielding  under  the 
gentle  pressure  of  forcing  the  edges  of  the  cap  into  contact  with  the 
dentin,  a  little  pain  will  sometimes  be  observed  ;  but 
unless  the  paste  is  too  stiff  no  compression  of  the  pulp  ^'  ^^-  ^^■^• 

should  be  caused. 

Pilling-  the  Cavity. — Whether  the  cavity  shall  be 
filled   temporarily  or   ])ermanently  depends   upon   the 
prognosis.     This,  as  will  be  perceived,  is  based  upon 
the  constitutional  conditions  and  the  state  of  the  pulp       ^,,^^  .^^  position. 
at  the  time  of  treatment. 

For  those  of  small  experience  in  this  line  of  treatment  it  would  not 
be  safe  to  attempt  the  permanent  stopping  of  the  cavity,  except  in  acci- 
dental exposures  and  in  cases  where  the  history  of  no  previous  dis- 
turbance can  be  elicited  and  where  the  thermal  reaction  is  slight.  Even 
in  the  latter  class  it  is  generally  best  to  delay  permanent  closure  by  a 
conductor  of  heat  until  after  an  experience  of  a  year  or  more  with  a 
non-conducting  stopjnng.  At  the  end  of  this  time  the  filling  may  be 
nearly  all  removed,  care  being  taken  not  to  disturb  the  cap,  when  with 
suitable  precaution  a  metallic  filling  may  be  inserted. 

In  the  majority  of  instances  it  is  safest  to  fill  the  cervical  part  wdth 
gutta-percha  stopping,  carrying  the  material  over  the  cap,  and  then  to 
complete  the  filling  with  zinc  phosphate.  In  this  way,  with  an  occa- 
sional renewal  of  this  temporary  work,  cases  may  be  carried  forward 
from  ten  to  fifteen   years. 

They   may,   however,   be    closed    permanently  and   safely  after    an 
experimental  trial  of  five  years  where   no  irritation  has  ai)peared. 
In   many  instances  recovery  takes  place  by  secondary  deposits  of 


414  CONSERVATIVE  TREATMENT  OF  THE  PULP. 

dentimil  tissue  the  exact  character  of  which  lias  nut  been  made  out. 
The  writer  has  observed  a  multitude  of  cases  in  practice  when  the  open- 
ing at  the  point  of  exposure  has  become  occluded  by  bony  tissue.  In 
some  instances  this  has  occurred  in  two  years,  in  others  after  longer 
periods.  In  one  instance  a  lateral  incisor  became  protected  by  this 
formation,  but  in  consequence  of  mistaken  diagnosis  of  another  condi- 
tion causing  pericementitis,  a  drill  was  passed  through  the  new  tissue 
to  the  living  j)ulp.  This  new  opening  healed  again.  In  the  same  mouth 
another  incisor  also  recuperated  in  the  same  manner. 

In  some  cases  when  entire  quiescence  has  been  maintained  for  many 
years  the  pulp  will  be  found  not  to  have  undergone  any  protective 
changes. 

It  is  not  remarkable,  however,  that  pulps  may  remain  in  a  state  of 
quiescence  for  a  long  period,  when  it  is  considered  that  in  slowly- 
advancing  caries  the  pulp  will  often  be  exposed  for  a  long  time  Avithout 
the  occurrence  of  any  signs  of  irritation,  unless,  by  the  position  of  the 
mouth  of  the  cavity,  the  pulp  has  been  subjected  to  the  pressure  of 
food. 

It  maybe  concluded' that,  whether  the  pulp  becomes  protected  by 
secondary  deposits  or  acquires  complete  quiescence,  conservative  treat- 
ment in  these  cases  has  considerable  advantage  over  immediate  devital- 
ization. Still,  in  this  connection  in  order  to  avoid  embarrassments  the 
necessity  exists  for  careful  selection  of  subjects  to  be  treated  in  this 
manner,  and  also  for  proper  analysis  of  the  apparent  condition  of  the 
pulp  itself.  To  aid  in  this  discrimination  the  following  summary  of 
conditions  should  be  held  in  mind  : 

(a)  Where  no  previous  observable  disturbances  can  be  elicited. 

(6)  Where  the  tooth  has  been  impressed  only  by  the  application  of 
low  temperature. 

(c)  Where,  in  addition,  reflected  pain  in  related  parts  has  been 
observed. 

(d)  Where  the  tooth  has  become  much  subject  to  impressions  by 
heat. 

(c)  Where  continued  objective  disturbances  appear,  such  as  soreness 
to  touch,  or  local  pain  of  spontaneous  character  accompanied  by  pulsa- 
tion. 

Classes  a,  b,  and  c  may  be  considered  as  amenable  to  treatment,  and 
also,  problematically,  class  d  if  taken  early.  Class  e  must,  in  view  of 
the  principles  stated  in  this  section,  be  eliminated  from  the  field  of  con- 
servative treatment ;  and  where  cases  in  the  other  divisions  apparently 
amenable  subsequently  take  on  disorders  coming  within  this  classi- 
fication they  usually  have  passed  beyond  the  reach  of  palliative  treat- 
ment. 


CAPPISG   THE  PULP.  415- 

It  is  important  here  to  consider  the  influence  of  the  physical  endow- 
ments of  the  patient  upon  the  conservative  treatment  of  the  pulp.  For 
some  persons  this  treatment  is  followed  by  the  happiest  results ;  no- 
intolerance  of  the  operation  appearing,  and  even  cases  somewhat  un- 
promising doing  well.  Again,  with  others,  any  case,  however  simple,, 
■goes  down  the  scale  to  class  e  in  spite  of  every  care. 

The  first  constitutional  condition  favorable  to  success  is  that  of 
soundness.  As  to  what  are  called  temperamental  indications,  when  the 
subject  is  of  good  health,  the  lymphatic  should  alone  be  excluded  and 
more  particularly  the  bilio-lymphatic.  These  latter  do  not  respond  to 
pulp  treatment  in  any  conditions  which  occur  to  them  ;  and  in  reference 
to  their  exposed  pulps  the  probabilities  are  that  in  the  sluggish  condi- 
tion of  the  parts  involved  the  organ  is  early  invaded  by  bacteria,  and 
such  changes  have  quickly  taken  place  in  the  anatomical  elements  of 
the  pulp  as  to  render  all  chances  of  successful  treatment  valueless.  The 
most  promising  cases  are  those  for  persons  of  active  temperaments,  with 
good  circulation,  thin  skins,  healthy  gums,  and  limpid  oral  secretions. 

After-treatment. — It  is  not  unusual  for  classes  a,  b,  and  c  to  require 
after-treatment.  For  this  reason  close  observation  for  some  time  should 
be  maintained.  It  is  presumed  that  the  judicious  operator  has  made 
careful  selection  of  the  cases  to  be  conservatively  treated  and  that  he 
will  early  decide  from  an  analysis  of  the  evident  conditions  whether  the 
prognosis  is  promising  or  not.  As  previously  indicated,  some  of  the 
apparently  favorable  cases  will  not  yield  to  treatment  for  the  reason 
that  the  actual  condition  of  the  pulp  may  not  be  made  out.  Part  of 
the  difficulty  here  is  occasioned  by  the  indefinite  character  of  the  state- 
ments of  the  patient,  who  should  in  all  cases  be  instructed  to  return  for 
consultation  if  painful  response  to  cold  appears  or  if  reflected  pain 
should  occur.  If  these  conditions  supervene,  it  is  a  sign  of  needed  care 
to  avert  increasing  disturbance. 

A  most  marked  form  of  reflected  pain  is  felt  in  the  ear,  and  this 
frequently  occurs  previous  to  the  aggravation  of  the  temperature  reac- 
tions. So  much  importance  should  be  attached  to  this  symptom  of 
pulp  disturbance  that  the  first  question  asked  a  patient  appearing  with, 
pain,  or  on  approaching  a  suspected  pulp,  is.  Have  you  had  any  pain 
in  the  ear  of  that  side?  As  reflection  to  the  ear  often  occurs  in  advance 
of  similar  pain  in  other  branches  of  the  fifth  pair,  it  becomes  important 
to  maintain  close  observation  of  this  indication.  In  this  state,  sedation 
combined  with  counter-irritation  is  required. 

In  any  case  where  tlie  tooth  has  been  impressed  by  cold,  either  before 
the  treatment  or  afterward,  an  application  should  be  made  to  the  gum 
over  the  tooth,  of  tincture  of  aconite  root  two  parts,  chloroform  one 
part.     The  mode  of  application  is  important.     A  pledget  of  cotton  or 


416  CONSERVATIVE  TREATMENT  OF  THE  PULP. 

nmsliii  to  cover  an  areii  of  one-half  by  three-fourths  of  an  inch  should 
be  tilled  with  the  prescription,  then  squeezed  out  nearly  to  dryness  between 
folds  of  a  napkin  to  prevent  an  excess  flowing  over  the  mouth  and  with 
the  saliva  entering  the  fauces,  to  which  it  is  extremely  irritating  as  well 
as  unnecessarily  medicating  the  patient.  Before  the  pledget  is  applied 
the  surface  of  the  gum  should  be  cleansed  of  the  coat  of  mucus  cover- 
ing it,  otherwise  the  remedy  will  fail  to  come  in  contact  with  the  mem- 
brane. It  is  equally  important  that  dryness  of  the  surface  be  secured. 
This  application  should  be  maintained  for  from  twelve  to  fifteen  seconds. 
If  allowed  to  remain  too  long  upon  the  j)art,  vesication  takes  place. 
The  general  after-treatment  consists  in  the  repeated  application  of  aco- 
nitum  as  above  directed,  the  repetitions  not  being  made  at  the  same  point 
more  frequently  than  at  intervals  of  forty-eight  hours.  When  it  is 
desired  to  increase  the  counter-irritation,  the  gum  may  be  scarified  very 
superficially  by  quick,  light  movements  of  a  small  scalpel.  The  patient 
should  be  instructed  to  avoid  subjecting  the  tooth  to  extremes  of  tem- 
perature in  either  direction.  The  control  period  of  conservatively 
treated  cases  is  usually  within  the  first  fortnight  after  the  capping. 

It  is  important  that  treatment  be  given  at  the  beginning  of  the  dis- 
turbance, when  a  few  applications  may  suffice.  Neglected  cases,  from 
the  tendency  to  pulp  disorders,  are  liable  to  pass  beyond  the  curative 
stage. 

The  interesting  phenomenon  is  frequently  observed  that  when  the 
heat  rate  rises  the  pulp  at  first  becomes  more  intolerant  of  cold.  In 
case  the  pulp  continues  to  respond  to  the  remedy  the  range  of  tolera- 
tion should  increase  in  both  directions. 

Examples:  No.  1,  W.  H.  J.,  +  108°--73°  ;  112^-76°;  +120° 
—  74°  ;  124°  -  74°  ;  128°  -  67°  ;  +  130°  -  66°.  No.  2,  I.  A.  W., 
+  120°  -84°;  +120°  -86°;  128° -86°;  +  124°-76°  ;  +  134°-70°  ; 
+  140° -67°;  +142° -66°;  +142° -64°. 

It  sometimes  becomes  necessary  to  open  the  cases  and  recap.  This 
iisuallv  occurs  when  in  reviewing  the  case  it  is  considered  that  some 
oversight  has  befallen.  There  may  have  been  two  exposures.  The 
cap  may  not  have  completely  covered  the  exposed  part.  There  may 
have  been  some  compression  from  forcing  the  cap,  or  it  may  have  been 
displaced  during  the  after-procedures. 

Most  careful  records  of  all  cases  should  be  kept,  with  a  relation  of 
the  condition  and  of  the  controlling  symptoms.  These  records  should 
be  methodically  preserved  in  a  book  kept  for  this  purpose.  Should  sub- 
sequent irritation  occur,  a  new  diagnosis  may  be  formed  from  the  recorded 
facts  and  the  new  conditions.  The  record  of  conservatively  treated  pulps 
should  be  carried  forward  to  the  examination  chart  at  each  recurring 
periodic  examination  of  the  teeth.     It  is  better  that  they  be  marked  in 


CALCIFIC  CHANGES  IN  THE  PULP. 


417 


symbol  with  red  ink,  to  prevent  the  unnecessary  removal  of  temporary 
fillings  and  to  explain  the  reason  for  their  presence  and  thus  avoid  the 
accident  of  unnecessarily  uncovering  the  pulp  in  such  cases. 


Oalcific  Changes  in  the  Pulp  as  related  to  the  Operation 

OF  Pulp  Capping. 

When  loss  of  substance  takes  place  slowly,  either  by  carious  action 
or  by  attrition,  a  notable  calcific  growth  takes  place  in  the  pulp  cham- 
ber opposite  to  the  point  of  waste  in  the  direction  of  the  radiant  course 

Fig.  394. 


Secondary  dentin,  resulting  from  irritation  of  the  dentinal  fibrils  by  caries  (Black).  A,  Diagram 
of  an  incisor  having  a  decay  in  the  hibial  surface,  a,  and  a  deposit  of  secondary  dentin  at  b. 
The  point  from  which  tlie  illustration  B  is  talien  is  shown  by  c.  B,  Illustration  of  the  tissue 
of  the  secondary  deposit  in  A :  a,  primary  dentin  :  h,  secondary  dentin :  c,  seems  to  be  a  blood- 
vessel that  has  become  calcified ;  d,  an  irregular  fault  having  some  resemblance  to  the  laeunse 
of  bone ;  e,  pulp  chamber.  It  will  be  noted  that  there  are  irregular  deposits  of  granular  matter 
in  the  substance  of  the  secondary  dentin,  and  that  the  tubules  wind  about  them. 

of  the  tubules  (see  Fig.  394).  If  the  loss  of  substance  from  the  ex- 
terior progresses  with  sufficient  slowness  encroachment  upon  the  pulp 
does  not  take  place.  The  pulp  chamber  may  become  obliterated  by  the 
progressive  deposition  of  calcific  matter,  which  has  the  designation  of 
secondary  dentin. 

The  morphological  character  of  the  secondary  deposit  is  histologically 
irregular,  being  frequently  of  mixed  character,  presenting  some  of  the 
characteristics  of  dentin  and  also  containing  cemental  cells  with  radiant 
and  anastomosing  canaliculi.  For  this  reason  deposits  have  been 
designated  as  osteo-dentin. 

In  the  earlier  years  of  life  opportunity  does  not  offer  to  study  these 
changes  of  structure,  as  the  usual  progress  of  caries  is  too  rapid,  but  in 
advanced  life  they  are  common,  it  being  not  infrequent  to  find  complete 

27 


418 


CONSERVATIVE  TREATMENT  OF  THE  PULP. 


obliteration  of  tlie  ])ulp  cavity  as  well  as  of  the  canal  of  the  root  (see 
Fig.  395).     In  some  instances  nodnles  of  calcific  material  appear  nn- 

FiG.  39o. 


Calcification  of  the  dental  pulp  (Black).  At  A  is  shown  the  outline  of  a  lower  molar  with  a  cavity 
at  b.  The  pulp  chamber  is  much  reduced  iu  size  and  filled  with  calcific  material,  as  shown  in 
B.  a,  a  large  granular  mass  of  calcific  material,  which  is  very  transparent  but  finely  granular. 
A  very  few  irregular  lines  are  seen  in  the  centre,  which  slightly  resemble  dentinal  tubes  ;  6, 
an  erratic  growth  of  irregularly  formed  and  unusually  transparent  dentin ;  c,  line  of  the 
growth  of  dentin  from  the  floor  of  the  pulp  chamber :  the  growth  from  other  directions  is  so 
perfectly  regular  as  to  leave  no  markings;  d,  margin  of  the  cavity  of  decay;  c,  a  bundle  of 
cylindrical  forms  of  calcific  material  extending  down  into  the  root  canal.  These  extended  to 
the  apex  of  the  root. 

attached  to  the  walls  of  the  pnlp  cavity  (Fig.  .396).     These  increase 
sometimes  by  external  development  and  in  other  cases  by  the  coalescence 

Fig.  396. 

A 


A,  Outline  of  a  lower  molar,  with  a  large  carious  cavity  at  o;  b,  pulp  chamber.  The  shaded  por- 
tion, c,  was  occupied  by  cylindrical  calcifications.  B,  Illustration  of  the  cylindrical  calcifica- 
tions.   X  100.    (Black.) 

of  several  contiguous  nodules.     Again,  several  nodules  inhabiting  the 
pulp  chamber  may  increase  in  size  without  becoming  fused,  and,  accom- 


CALCIFIC  CHANGES  IN  THE  PULP.  419 

modating  themselves  to  each  otlier  as  development  progresses,  they  at 
length  completely  fill  the  cavity,  from  Avhich  tliey  are  severally  removed 
with  great  difficulty. 

It  is  remarkable  that  while  in  some  instances  pul])  nodules  become 
the  cause  of  producing  violent  pain  by  their  pressure  upon  the  nerves 
of  the  pulp,  in  the  majority  of  cases  substitution  of  the  normal  tissue 
takes  place  until  nearly  complete  occlusion  of  the  pulp  cavity  is  affected 
without  the  occurrence  of  pain. 

Small  pulp  nodules  are  not  infrequently  found  in  pulps  otherwise 
perfectly  normal,  but  generally  they  are  evidence  of  continued  irritation 
of  a  mild  form  usually  attending  the  progressive  slow  advancement  of 
caries  of  the  tooth.  But  this  is  not  necessarily  the  case,  since  some  of 
the  most  violent  attacks  of  dental  neuralgia  have  arisen  from  the  pres- 
ence of  nodules  in  perfectly  sound  teeth. 

The  diagnosis  of  the  existence  of  pulp  nodules  as  the  cause  of  pulp 
irritation  is  not  easily  made  out.  The  determination  of  the  condition 
usually  can  be  reached  only  by  the  process  of  exclusion.  As  they  do 
not  occur  early  in  life  while  the  teeth  are  undergoing  ordinary  develop- 
ment, they  may  be  looked  for  only  after  middle  life.  The  pain  is  dull 
and  reflected,  and  the  paroxysms  are  frequent.  There  is  sensibilitv  to 
cold,  and  rarely  pain  appears  on  percussion.  AVhen  the  teeth  are 
sound,  the  disturbing  one  will  usually  be  determined  by  the  tem- 
perature tests. 

An  important  differentiation  from  the  usual  irritation  of  ordinary 
pulp  disturbance  from  exposure  or  the  thermal  irritation  caused  by  the 
approximation  to  the  pulp  of  large  metal  fillings,  is  that  the  disturbance 
from  nodular  irritation  is  not  rapidly  progressive  and  that  the  irritation 
may  continue  without  marked  exacerbations  or  subsidence  for  consider- 
able periods. 

Treatment  is  useless  which  does  not  include  drilling  to  the  pulji  and 
devitalizing  it.  The  difficulties  involved  in  treatment  by  devitalization 
are  liable  to  be  attended  by  great  pain,  since  when  the  pulp  chamber  is 
much  occupied  by  nodules  the  action  of  the  devitalizing  agent  has  not 
free  course.  In  these  cases  tlie  remains  of  the  pulp  between  the  nodules 
and  the  walls  of  the  chamber  are  attenuated,  and  wlien  irritated  by  the 
arsenous  acid  give  expression  to  an  excessive  degree  of  pain.' 

The  Influence  of  Pulp  Exposure,  and  the  Effect  of  Conservative  Treat- 
ment of  the  Pulp  upon  Calcific  Pepof^itions. — Allusion  has  been  made 
to  calcific  deposits  occurring  on  the  walls  of  the  pulp  chamber  as  the 
result  of  peripheral  irritation.  Here,  as  stated,  these  accretions  only 
occur  when  the  degree  of  irritation  is  slight  and  of  long  continuance. 
The  examples  of  this  which  have  been  given  in  dental  literature  are 

^  For  the  form  and  extent  of  nodular  calcification  see  American  System  of  iJentisiry. 


420  CONSERVATIVE  TREATMENT  OF  THE  PULP. 

conclusive  as  to  the  ability  of  the  pulp  at  all  stages  of  its  existence  to 
take  on  this  action  when  the  conditions  are  as  stated.  On  the  contrary, 
when  the  disturbances  are  active  the  formation  of  calcific  deposits  on 
the  walls  of  the  pulp  chamber  do  not  take  })lacc,  or  if  in  the  earlier 
progress  of  decay  they  have  commenced,  as  the  j)rogress  of  the  destruc- 
tive action  ap})roaches  the  pulp  this  (change  is  suspended,  and  in  some 
instances  resorption  of  the  secondary  deposit  takes  j)lace. 

It  is  apparently  in  this  manner  that  the  pulp  becomes  denuded  under 
the  influence  of  thermal  or  traumatic  irritation  in  cases  in  which  there 
was  no  evidence  of  exposure  at  the  time  of  the  preparation  and  filling 
of  the  cavity.  This  result  would  appear  to  be  related  to  the  principle 
that  secondary  structures  and  tissue  of  repair  are  liable  to  resorption  as 
the  result  of  irritation  or  disturbances  of  nutrition. 

The  frequent  occurrence  of  secondary  dentin  following  the  conserva- 
tive treatment  of  the  pulp  and  in  some  instances  occurring  spontaneously 
over  exposed  pulps,  raises  imjmrtant  considerations  connected  with  the 
subject.  The  writer  has  had  many  instances  come  under  his  observation 
in  which  secondary  dentin  has  obliterated  exposures,  both  in  his  own 
cases  and  in  those  of  others. 

The  influence  of  the  tendency  to  nodular  deposits  upon  the  results 
of  conservative  treatment  does  not  appear  to  be  detrimental  unless  the 
pulp  chamber  becomes  largely  filled  with  them.  The  pulp  at  the  period 
of  life  when  calcific  deposits  usually  take  place  is  not  so  sensitive  as  it 
is  at  an  earlier  age,  and  therefore,  unless  senile  conditions  appear  to  be 
present  or  imminent,  the  existence  of  such  deposits  should  not  be  inim- 
ical to  the  preservation  of  the  pulp.  The  writer,  who  has  had  frequent 
cases  of  pulp  devitalization  after  conservative  treatment,  has  rarely  ob- 
served "  pulp  stones  "  in  these  cases. 

It  is  an  important  consideration  that  when  calcific  deposits  take 
place  beneath  fillings  where  the  pul])  has  been  nearly  exposed,  or  where 
they  have  followed  conservative  treatment  of  the  pulp,  they  arc  liable 
to  resorption  on  the  occurrence  of  irritation  of  the  pulp  from  any  cause 
which  brings  on  an  increased  blood  supply.  This  is  more  remarkable 
since  there  are  no  lymphatic  vessels  in  the  pulp.  This  change  can  occur 
only  by  the  development  of  osteoclasts  on  the  surface  of  the  pulp. 
Of  this  development  there  have  been  several  recorded  instances 
where  the  dentin  has  suffered  resorption  until  the  enamel  has  been 
encroached  upon  by  the  process  of  denudation,  and  when  favorable 
conditions  were  established  a  deposition  or  formation  of  secondary 
dentin    has    occurred. 


DEVITALIZATION  AND  EXTIRPATION  OF  THE  PULP.        421 


Devitalization  and  Extirpation  of  the  Dental  Pulp. 

When  the  existing  conditions  are  snch  as  to  require  the  devitalization 
of  the  pulp  there  are  several  requirements  essential  to  secure  a  satis- 
factory result : 

(i)  That  little  pain  be  inflicted. 

(2)  That  the  destruction  be  quickly  effected. 

(3)  That  precaution  be  taken  to  prevent  discoloration  of  the  dentin. 
The  first  requirement  is  the  most  important,  since,  if  the  means  used 

to  effect  the  devitalization  are  painless  or  nearly  so,  the  pulp  promptly 
yields  to  the  devitalizing  agent  and  there  is  little  danger  of  discoloration 
of  the  dentin. 

At  present  there  are  three  general  methods  of  procedure  :  by  chemi- 
cal means,  by  extirpation  with  suitable  instruments,  and  by  narcotization 
of  the  tissue. 

Reliance  has  usually  been  placed  upon  chemical  agents,  these  being 
— 1.  Zinc  chlorid  ;  2.  Caustic  potassa ;  3.  Chromic  acid;  4.  Arsenous 
acid  ;  5.  Arsenical  ore  (cobalt). 

The  agents  1,  2,  3  are  usually  painful,  of  slow  progress,  difficult  of 
application,  and  uncertain.  Hence  arsenous  acid  has  usually  been 
depended  on.  This  substance,  notwithstanding  certain  objections,  is  the 
most  available  and  most  reliable  of  the  substances  above  named.  It 
has  generally  been  combined  with  acetate  of  morphin  in  variable  pro- 
portions, to  which  has  been  added  in  the  formation  of  this  paste  a  suf- 
ficient quantity  of  creosote,  carbolic  acid,  or  one  of  the  essential  oils,  to 
give  the  combination  the  consistence  of  cream.' 

In  making  this  formula  it  is  important  that  the  ingredients  be 
thoroughly  ground  together  to  effect  the  comminution  of  the  arsenic 
and  the  morphin  as  well  as  to  intimately  mix  the  components.  The 
morphin  is  used  as  a  sedative  to  counteract  the  excessive  irritation  fre- 
quently caused  by  the  action  of  the  arsenous  acid,  which  is  also  modified 
by  the  anesthetic  influence  of  the  creosote.  Carbolic  acid  has  been  fre- 
quently substituted  for  creosote  as  being  of  less  disagreeable  odor,  and 
as,  from  its  coagulatlve  action  upon  the  surface  of  the  pulp,  it  prepares 
the  tissue  to  absorb  the  arsenic  and  markedly  lessens  the  time  of  absorp- 
tion. It  is  a  well-known  fact  that  with  great  frequency  the  application 
of  arsenous  acid  to  the  pulp  is  so  greatly  irritating  to  it  that  much  pain 

*  Of  late  cocain  has  largely  superseded  the  morphin  salt  as  an  ingredient  of  these  pre- 
scriptions.    As — 

B  Acid,  arsenosi, 

Cocainre  hydrochl.,  da.  pars  aeq. 

Ol.  caryopliylli,  q.  s. 

M.  et  ft.  pasta. 


422  CONSERVATIVE  TREATMENT  OF  THE  PULP. 

is  excited,  which  brings  about  congestion  of  tlie  surface  of  tlie  pulp  to 
such  a  degree  as  to  delay  absor})tion  of  this  agent. 

When  the  above-stated  combination  is  applied  to  a  living  pulp  which 
has  not  been  in  a  state  of  disturban(;e,  and  therefore  is  in  the  condition 
of  quiescence  considered  in  the  section  on  conservative  treatment  of  the 
pulp,  little  or  no  excitement  of  the  organ  takes  place.  If  the  paste  be 
carefully  a})j)licd  in  such  a  manner  as  to  avoid  pressure  the  pulp  does 
not  usually  become  excited  and  promptly  succumbs  to  the  chemical  force 
of  the  arsenic.  When  on  the  contrary  the  pulp  is  in  a  condition  of 
active  congestion,  such  as  is  presented  by  cases  of  prolonged  exposure, 
and  where  congestion  has  supervened  as  the  consequence  of  futile 
attempts  at  conservation,  violent  further  excitement  of  the  pulp  is 
nearly  certain.  In  this  condition  the  pulp  resists  the  absorption  of  the 
arsenic  and  repeated  applications  are  likely  to  produce  no  better  results. 
The  failure  to  discriminate  between  the  different  conditions  of  the  pulp 
accounts  largely  for  the  variation  in  the  action  of  the  same  formula 
upon  the  exposed  pulp. 

It  becomes  important,  therefore,  to  reduce  the  state  of  hyperesthesia 
of  the  pulp  and  to  relieve  the  congestion  in  many  instances  before 
commencing  the  devitalization. 

The  7'clief  of  conf/e.stion  requires,  first,  the  disinfection  of  the  surface 
of  the  pulp'  and  of  the  dentin  contiguous  to  it.  The  most  efficient 
agent  for  this  purpose,  generally,  is  formalin,  which  after  the  first  slight 
pain  produced  by  it  is  almost  immediately  soothing.  Formalin  owes 
its  value  as  a  disinfectant  to  its  extreme  diffusibilityand  in  the  strength 
applicable  does  not  appear  to  be  coagulative  in  its  action.  The  strength 
should  for  this  purpose  not  be  greater  than  2^-  per  cent.  As  formalin  is 
composed  of  40  volumes  of  formaldehycl  with  60  of  water,  the  above- 
stated  percentage  of  formaldehyd  is  produced  by  adding  1  volume  of 
formalin  to  14  volumes  of  water. 

When  violent  congestion  is  manifest  and  when  the  pain  attending 
the  removal  of  the  carious  matter  forbids  the  complete  baring  of  the 
pulp,  a  paste  composed  of  tannic  acid  and  oil  of  cloves  sealed  in  the 
cavity  will  so  far  subdue  the  conditions  as  to  permit  complete  removal 
of  the  caries.  This  application  should  be  allowed  to  remain  for  several 
days.  This  ])aste  should  be  contained  in  a  large  concave  cap  and 
secured  with  one  of  the  plastic  cements. 

For  the  relief  of  ordinary  congestion  of  the  pulp  cocain  offers  the 
best  means,  since  it  has  direct  and  positive  action  over  the  capillaries, 
which  has  generally  been  adduced  to  account  in  part  for  its  anesthetic 
influence,  as  by  lessening  the  supply  of  blood  in  the  capillaries  it  there- 
by reduces  the  stimulation  of  the  nerve  fibrils.  In  cases  of  known  con- 
gestion as  determined  by  the  symptomatology  when  there  is  no  effusion 


DEVITALIZATION  AND  EXTIRPATION  OF  THE  PULP.         423 

of  lymph  or  pus  from  the  exposed  surface,  the  pulp  is  bathed  with  a 
strong  solution  of  cocain  and  is  then  covered  with  a  deep  cap  filled  with 
a  paste  of  cocain  and  oil  of  cloves  hermetically  sealed  in  for  several 
days,  when  usually  the  arsenical  paste  may  be  used  with  much-lessened 
danger  of  irritation. 

In  these  cases,  and  indeed  in  all  cases,  an  excellent  formula  for  de- 
vitalization will  be  found  in  the  combination  of  10  grams  of  arsenous 
acid  ground  well  with  20  grams  of  cocain.  This  is  taken  upon  a  minute 
pledget  of  cotton  previously  charged  with  oil  of  cloves  or  carbolic  acid, 
which  is  laid  upon  the  exposed  point  and  then  sealed  in  hermetically, 
care  being  taken  to  avoid  compression  by  arching  over  the  dressing  a 
suitable  cap,  or  by  fiowing  over  the  dressing  a  soft  paste  of  one  of  the 
mineral  cements.  Too  much  care  cannot  be  taken  concerniup:  the 
protection  of  the  gum  from  escape  of  the  arsenical  preparation,  since 
serious  destruction  of  the  gum  and  alveolus  may  be  produced  by  the 
exuding  of  the  arsenic. 

When  there  is  evidence  of  the  exudation  of  pus,  this  is  checked  by 
the  application  of  deliquescent  zinc  chlorid  or  by  washing  with  pyrozone. 
Usually  in  such  cases  the  surface  of  the  pulp  has  become  necrotic  by 
the  suppurative  process  and  will  not  be  so  repellant  of  the  arsenic  as  in 
ordinary  cases. 

The  time  usually  required  for  the  action  of  the  arsenic  to  reach  well 
toward  the  apex  of  the  roots  is  from  four  to  six  days.  This,  however, 
depends  upon  the  quantity  of  the  preparation  applied  and  the  resistance 
of  the  pulp  tissue.  As  the  aim  should  be  to  procure  the  nearly  com- 
plete death  of  the  pulp  l)y  one  a})plication,  the  longer  period  is  preferable 
as  entailing  less  difficulty  and  the  expenditure  of  less  time  than  when 
shorter  intervals  arc  allowed. 

When  the  application  is  made  to  an  entirely  quiescent  pulp  it  will 
often  be  found  that  at  the  end  of  one  or  two  days  a  broach  may  be 
passed  to  the  end  of  single-rooted  teeth,  when  the  pulp  may  sometimes 
be  removed.  In  these  cases,  if  the  pulp  be  not  then  extracted,  it  will 
be  found  in  some  instances  that  at  a  subsequent  period  the  organ  has 
apparently  recovered  its  sensitivity.  The  explanation  of  this  is  that  the 
arsenic  apparently  paralyzes  the  nerves  of  the  pulj)  without  having  acted 
deeper  than  the  surface.  In  this  case  the  application  should  be  repeated 
for  a  lengthened  period  without  disturbing  the  tissue.  On  removing 
the  dressings  if  the  broach  cannot  be  passed  to  the  end  of  the  canal 
either  of  two  courses  may  be  pursued  ;  the  application  may  be  repeated 
without  removing  the  devitalized  portion,  or  a  strong  solution  of  cocain 
may  be  carefully  instillated  until  it  is  conveyed  to  the  apex  of  the  canal 
by  means  of  a  broach.  This  procedure  is  best  effected  by  isolating  the 
tooth  with  rubber  dam  and  then  filling  the  pulp  chamber  with  the  solu- 


424  CONSERVATIVE  TREATMENT  OF  THE  PULP. 

tion  of  cocain,  which  may  be  conveniently  conveyed  forward  by  gentle 
advancements  and  withdrawals  of  this  instrument.  The  best  form  of 
instrument  for  this  purpose  is  the  Swiss  broach  tempered  a  little  beyond 
a  spring  temper. 

A  matter  of  considerable  importance  in  connection  with  the  instru- 
ments used  in  these  manipulations  is  that  they  be  either  such  as  have 
not  been  previously  used  or  that  they  be  thoroughly  disinfected  previous 
to  use.  If  an  instrument  of  this  kind  is  indiscriminately  used,  having 
probably  been  infected  by  some  purulent  case,  septic  disturbance  of  the 
tissues  at  the  apex  is  brought  about.  The  safest  course  is  to  use  a  new 
broach  suited  in  size  and  stiffness  to  the  case  in  hand. 

Since  cataphoresis  has  been  employed  in  dentistry  it  has  been  fre- 
quently used  to  effect  the  anesthetization  of  the  pulp  by  cocain.  This 
method  has  certain  advantages.  The  time  expended  in  the  procedure 
is  from  ten  to  thirty  minutes.  The  requirements  are  that  insulation  be 
perfectly  secured ;  that  the  selected  voltage  be  low  at  the  commence- 
ment— in  most  instances  from  5  to  10  volts — and  be  gradually  increased 
as  the  pain  limit  will  permit. 

The  impediments  are  the  usual  small  size  of  the  foramina  and  the 
density  of  the  pulp  walls.  When  the  foramen  is  large  the  resistance  is 
less  and  the  action  prompt. 

Cocain  may  be  employed  in  this  manner  to  obtund  the  parietes  of  the 
cavity  and  the  surface  of  the  pulp,  when  after  the  removal  of  the  carious 
matter  the  pulp  may  be  uncovered.  The  application  can  then  be 
renewed  to  complete  the  anesthetization  of  the  pulp. 

This  procedure  saves  much  time  and  discomfort  and  also  avoids 
pain  as  compared  with  devitalization  by  chemical  means.  It  is  indi- 
cated in  cases  of  severe  congestion  of  the  pulj),  in  M'hich  arsenic  usually 
produces  great  pain  and  often  is  without  satisfactory  result. 

In  some  instances  complete  obtundation  is  not  effected  throughout 
the  extent  of  the  pulp.  Here,  after  removal  of  the  part  anesthetized 
the  remainder  may  be  devitalized  easily  by  "  White's  fiber,"  which  is 
the  safest  arsenical  preparation  to  use  under  these  conditions. 

Instillation  of  cocain  by  means  of  a  broach  may  also  be  efficacious. 

A  further  advantage  in  this  method  of  treatment  is  that  when  the 
anesthesia  is  completed  the  pulp  may  be  entirely  removed  and  the 
canal  be  filled  at  the  same  sitting. 

It  is  sometimes  observed,  as  the  result  of  forcing  the  current  beyond 
reasonable  limits,  that  soreness  of  the  peridental  membrane  follows. 
AVhat  effect  has  been  produced  in  this  instance  is  not  clearly  apparent. 
AVhether  it  is  a  result  of  undue  pressure  of  the  current  upon  the  apical 
tissues  or  is  caused  by  the  interference  of  cocain  with  the  nutrition  of 
the  parts  has  not  been  determined.     This  effect  is  mentioned  to  induce 


PRECAUTIONS  TO  PREVENT  DENTINAL  DISCOLORATION    425 

the  degree  of  caution  which  is  the  accompaniment  of  an  intelligent  use 
of  a  force  of  signal  service  when  carefully  applied,  but  which  recklessly 
pushed  may  do  injury.^ 

The  Pressure  Method  of  Obtunding  the  Pulp. 

A  method  of  applying  cocain  to  the  pulp  under  pressure  has  recently 
come  into  use.  It  consists  of  laying  over  the  exposed  surface,  after 
the  pulp  is  carefully  and  broadly  uncovered,  a  small  piece  of  amadou 
(punk)  filled  with  a  saturated  solution  of  cocain  in  absolute  alcohol  or 
chloroform.  The  cavity  is  then  filled  with  a  piece  of  unvulcanized 
caoutchouc.  Pressure  is  effected  directly  upon  the  rubber  Avith  a  broad 
rounded  instrument,  so  adapted  in  size  that  it  will  not  meet  with 
impediment  and  yet  not  small  enough  to  exert  force  directly  upon  the 
point  of  exposure.  The  degree  of  pressure  should  at  first  be  slight,  and 
be  gradually  increased  as  the  cocain  exerts  its  effect  upon  the  pulp. 
The  force  is  exerted  by  successive  steps,  terminating  when  pain  follows, 
but  maintained  until  the  sensation  ceases.  At  length  when  no  pain  is 
produced  by  excessive  pressure  the  rubber  and  punk  are  removed,  when 
the  pulp  is  immediately  removed  by  the  usual  means.  This  operation 
is  done  quickly,  to  avoid  the  return  of  sensitivity. 

Those  who  pursue  this  plan  state  that  it  produces  nearly  uniform 
results  and  enables  the  canal  and  pulp  chamber  to  be  filled  immediately. 

The  indications  are  that  the  cocain  overcomes  the  sensitivity  of  the 
surface  of  the  pulp,  and  that  pressure  paralyzes  the  tissue  by  the  com- 
pression to  which  it  is  subjected.  Were  the  cocain  conveyed  to  the 
apex,  as  when  it  is  instillated,  pain  would  not  so  soon  return. 


Precautions  required  to  Prevent  Discoloration  of  the 

Dentin. 

It  sometimes  occurs  where  arsenous  acid  produces  much  irritation 
of  the  pulp  that  the  violent  congestion  occasions  disorganization  of  the 
blood  corpuscles,  resulting  in  the  distribution  of  the  hcmatin  throughout 
the  dentin.  This  most  unfortunate  result  is  liable  to  follow  the  applica- 
tion to  an  already  congested  pulp  when  the  application  is  made  without 
first  subduing  this  condition.  It  is  also  more  liable  to  happen  when 
under  these  circumstances  the  pulp  has  not  been  completely  denuded  of 
the  carious  matter. 

The  removal  of  the  ultimate  layers  of  carious  matter  is  important  to 
permit  the  pulp  to  bleed  and  thus  to  deplete  the  engorged  vessels.  It 
is  also  necessary  to  avoid   making  an  arsenical  application  until  the 

'  The  student  will  find  much  instruction  in  Price's  "Foundation  Principles  of  Den- 
tal Cataphoresis,"  Items  of  Interest,  vol.  xx.  p.  345  et  seq. 


426  CONSERVATIVE  TREATMENT  OF  THE  PULP. 

assurance  is  reached  that  the  bkn'ding  has  completely  ceased,  else  subse- 
quent bleeding  may  induce  discoloration.  In  addition  the  bleeding  or 
any  other  kind  of  eflPusion  prevents  direct  contact  between  the  pulj)  and 
the  arsenical  paste. 

These  general  directions  apply  also  to  the  employment  of  pow- 
dered cobalt  as  a  devitalizer.  The  difference  between  the  action  of 
cobalt  and  arsenous  acid  is  due  to  the  variations  in  their  respective 
solubility  in  the  fluids  of  the  pulp — cobalt  having  a  low  rate  of  solu- 
bility. For  this  reason  this  substance  requires  a  longer  interval,  at 
least  a  week  being  necessary  for  its  action  to  extend  into  the  canals.  In 
anterior  teeth  a  shorter  period  should  be  chosen.  With  this  substance 
it  is  of  extreme  importance  that  the  application  be  made  directly  to  the 
pulp.     The  method  is  as  follows  : 

A  pellet  of  cotton  the  size  of  a  pinhead  is  saturated  -with  any  of  the 
essential  oils  ;  it  is  then  dipped  in  the  powder  and  laid  upon  the  pulp. 
The  previously  stated  precautions  are  taken  to  prevent  pressure  of  the 
pellet  of  cotton  upon  the  pulp  and  to  protect  the  cavity  from  the  ingress 
of  moisture. 

In  these  procedures  connected  with  the  removal  of  the  pulp  the  use 
of  alcohol  is  an  important  aid,  since  on  account  of  its  affinity  for  water 
it  much  aids,  in  addition  to  its  cleansing  properties,  in  the  procurement 
of  dryness  of  the  parts.  Desiccation  of  the  pulp  chamber  materially 
assists  in  all  the  delicate  procedures  connected  with  the  treatment  of 
this  class  of  cases.  It  lessens  the  pain  of  the  remaining  living  portion 
of  the  pulp,  and  by  giving  firmness  to  the  devitalized  part  makes  more 
easy  the  removal  of  the  dead  tissue.  It  also  facilitates  the  action  of  the 
disinfectants  which  may  be  employed  to  prevent  rapid  changes  in  the 
organic  contents  of  the  canal.  The  process  of  desiccation  may  be  much 
facilitated  by  the  concurrent  injection  of  warmed  air. 

It  should  be  emphasized  that  in  all  procedures  connected  with 
the  treatment  of  pulps  undergoing  devitalization  the  teeth  should  be 
isolated  by  the  use  of  rubber  dam.  This  is  necessary  not  only  to 
facilitate  observation  and  secure  dryness  but  to  protect  from  mouth 
infection. 

The  removal  of  the  dead  pulp  tissue  is  effected  by  small  barbed 
broaches  which  are  passed  between  the  pulj)  and  the  walls  of  the  canal. 
When  these  reach  the  apex  the  pulp  may  in  most  instances  be  wound 
upon  the  instruments  by  a  gentle  rotation.  When  this  does  not  take 
place  because  of  the  loss  of  consistence  of  the  tissue,  it  is  broken  up  by 
constant  rotation  of  the  instrument  and  removed  piecemeal.  The  dis- 
placement of  the  shreds  is  best  effected  by  wrapping  the  broach  with  a 
few  fibers  of  cotton  dipped  in  alcohol. 

Previously  to  this,  free  communication  must  be  established  between 


PRECAUTIONS  TO  PREVENT  DENTINAL  DISCOLORATION.    427 

the  cavity  and  the  pulp  chamber,  as  well  as  such  a  formation  of  the 
lines  of  approach  to  the  canals  of  the  root  as  Avill  give  free  access,  not 
only  for  the  removal  of  the  dead  tissue,  but  as  well  to  facilitate  the 
complete  closure  of  the  root  canals  to  the  apices  to  prevent  the  ingress 
of  organic  matter  from  the  adjacent  tissues. 

Minute  directions  for  the  form  of  approach  to  the  various  canals  and 
the  related  procedures  will  be  found  in  the  next  chapter. 


CHAPTER   XVII. 

THE  TREATMENT  AND  FILLING  OF  ROOT  CANALS. 

By  Henry  H.  Burchard,  M.  D.,  D.  D.  S. 


Pathological  Conditions. 

The  modes  of  treatment  of  the  pulp  chambers  and  canals  of  teeth 
containing  non-vital  pulps,  or  those  in  which  the  pulp  is  absent,  are 
determined  and  governed  by  the  pathological  conditions  present.  These 
conditions  may  be  broadly  divided  into  aseptic  and  septic ;  i.  e.  those 
which  have  not  been  invaded  by  micro-organisms,  the  others  those  in 
which  the  pulp  or  its  remnants  furnish  the  soil  in  which  the  develop- 
ment of  micro-organisms  has  taken  place. 

The  first  class  includes  those  cases  in  which  the  pulp  has  been  inten- 
tionally devitalized  en  masse,  and  also  those  in  which  the  organ  has 
undergone  a  process  known  as  mummification,  or  dry  gangrene.  This 
latter  condition  is  occasionally  found  as  a  consequence  of  traumatic 
death  of  the  pulp  without  exposure,  and  sometimes  as  a  sequel  of 
attempts  at  conservation  of  exposed  pulps  by  capping  them  with  zinc 
oxychlorid. 

The  septic  cases  may  be  divided  into  classes  according  to  the  depth 
of  invasion  of  septic  organisms  ;  they  range  from  superficial  ulceration 
of  the  pulp,  to  its  disorganization  through  the  agency  of  ])utrefaction, 
and   the  infection  of  the  tissues  beyond  the  apex  of  the  root. 

Immediately  upon  or  even  before  exposure  of  the  dental  pulp, 
its  surface,  and  subsequently  its  substance,  is  invaded  by  several 
of  the  many  forms  of  organisms  which  find  a  habitat  in  the  human 
mouth. 

The  first  of  the  septic  cases  are  those  in  which  organisms  have 
invaded  the  coronal  portion  of  the  pulp  and  destroyed  part  of  its  sub- 
stance— through  a  process  of  ulceration.  Such  cases  become  aseptic 
through  the  removal  of  the  pulp  en  masse,  provided  no  organisms  be 
carried   into   the   canal   during  or   subsequent   to   the   removal  of  the 

pulp. 

The  second  class  of  cases  comprises  those  in  which  septic  organisms 
have  invaded  the  pulp  along  the  direction  of  its  veins  and  destroyed 
the  mass  of  the  organ  through  a  process  of  suppuration.     In  these  cases 

429 


430 


THE  TREATMENT  AND  FILLING   OF  ROOT  CANALS. 


it  is  not  uncommon  to  find  the  tissues  of  the  apical  region  affected  in 
some  degree  presumably  by  infection  with  the  waste  products  of  the 
organisms,  a  transitory  pericementitis  occurring  which  ceases  when  the 
dead  pulp  sloughs  from  its  vital  connection  at  the  apex.  The  succeed- 
ing stages  of  the  infection  are  those  of  moist  gangrene  and  putrefactive 
decomposition  of  the  pulp  tissues,  and  later  of  the  contents  of  the 
tubules.  Following  upon  these  conditions  are  affections  of  the  cemen- 
tnm  and  the  pericementum  in  the  apical  region,  resulting  in  an  inflam- 
matory process  in  these  parts. 

All  of  these  stages  of  infection  and  decomposition  may  be  found  in 
the  pulp  at  one  time,  the  suppurative  process  preceding  that  of  putre- 
faction.    Cultures  made  from  a  gangrenous  pulp  (see  Fig.  397)^  showed 


Fig.  397. 


--> 


Micro-organisms  found  in  cultures  from  a  gangrenous  pulp. 

the  smaller  cocci  and  diplococci  (5)  nearest  the  apex  of  the  root  (c,  Fig. 
397,  1)  where  suppuration  was  in  progress  ;  the  larger  forms  and  more 
varieties  were  found  in  the  necrosed  and  decomposing  portions  of  the 

'  Miller,  Dental  Cosmos,  July,  1894. 


PATHOLOGICAL   CONDITIONS.  431 

pulp  (4,  3,  2).     The  cases  of  gangrenous  pulps  exhibit  a  mixed  infec- 
tion, several  varieties  of  cocci,  bacilli,  and  spirochc^etes  being  found.' 

Cases  are  occasionally  seen  in  which  the  pulp  of  a  non-carious  tooth 
has  been  devitalized  in  consequence  of  a  blow,  injuring  the  vessels  as 
they  enter  the  apex  of  the  root ;  the  same  effect  is  not  rare  as  a  conse- 
quence of  too  rapid  or  extensive  movement  of  teeth  in  regulating.  The 
pulps  in  such  cases  are  probably  destroyed  by  thrombosis  of  the  vessels 
at  the  root  apex.  The  death  of  the  pulp  may  not  be  detected  for  years  ; 
when  evidences  of  albuminous  decomposition  are  discovered,  a  growing 
opacity  and  changing  color  of  the  tooth  may  be  detected.  In  other 
cases  alveolar  abscesses  may  form  and  discharge  at  some  point  near  the 
tooth,  or  it  may  be  at  some  distance  from  it.  It  is  presumed  that  the 
organisms  which  have  effected  this  decomposition  of  the  pulp  resulting 
in  the  suppurative  process  have  found  their  way  to  it  via  the  blood 
current. 

It  is  within  the  experience  of  every  dentist  that  the  products  of 
decomposition  occurring  under  these  conditions  afford  a  suitable  soil  for 
the  development  of  virulent  micro-organisms  as  soon  as  the  tooth  is 
opened  to  the  air. 

The  several  conditions  described  are  to  be  regarded,  for  purposes  of 
treatment,  as  definite  pathological  states.  The  treatment  is  to  be 
directed  to  the  attaining  of  such  conditions  as  shall  insure  the  retention 
of  the  tooth  with  an  entire  absence  of  pathological  manifestations. 
Rational  therapeutics  should  govern  each  procedure. 

Cases  in  ivhich  the  Pulp  has  been  Intentionally  Destroyed  and  Re- 
moved en  masse. — As  this  procedure  usually  has  been  determined  upon 
in  consequence  of  suppuration  or  inflammation  of  the  pulp,  the  septic 
organisms,  the  staphylococci,  streptococci,  and  bacilli,  have  followed 
the  course  of  the  inflammation,  /.  e.  along  the  veins.  The  organisms  of 
putrefaction,  if  present,  have  affected  but  in  very  limited  degree  the 
most  external  portions  of  the  pulp,  so  that  the  color  of  the  dentin  is 
unaltered  except  to  a  very  slight  depth.  After  the  removal  of  the  pulp 
the  contents  of  the  tubules  are  chemically  unchanged,  and  the  canals 
contain  no  organic  matter,  except  the  blood  which  may  have  escaped  in 
consequence  of  tearing  away  the  pulp.  There  may  also  remain  odonto- 
blasts which  have  become  mechanically  detached  during  the  operation. 
Provided  no  organisms  have  been  introduced  during  or  subsequent  to 
the  operation  of  extirpation,  the  canals  are  aseptic.  If  proper  anti- 
septic precautions  have  been  taken,  sterilizing  and  isolating  the  tooth  to 
be  operated  on  and  also  the  instruments  employed,  no  infection  occurs. 
These  are  the  cases  in  which  immediate  root  filling  has  been  recom- 
mended and  practised  with  success. 

'  See  Fig.  397. 


432 


THE  TREATMENT  AND  FILLING   OF  ROOT  CANALS. 


Pigment. 


Fici.  398. 
S  -I-  hemoglobin. 


COo.NHa; 
H2O  and  HjS 


Aromatic  and 
fatty  prod- 
ucts. 


If  the   septic   process   has   invaded  the   l)ulp   extensively  the   pulp 

tissue,  as  its  destmu^tion  progresses,  be- 
comes the  seat  and  soil  of  putrefactive 
decomposition  involving  also  to  a  vari- 
able extent  the  contents  of  the  dentinal 
tubules,  and  the  color  of  the  dentin  un- 
dergoes a  series  of  changes.'  The  ap- 
pended figure  (Fig.  398)  gives  a  graphic 
diagrammatic  representation  of  the  serial 
decomposition  of  an  infected  pulp.  The 
albuminous  constituents  of  the  pulp  un- 
dergo fatty  transformation ;  next  putre- 
factive decomposition  attended  by  the 
evolution  of  hydrogen  sulfid,  ammonia, 
and  other  end  products.  According  to  the 
extent  of  invasion  and  its  variety,  waste 
products  are  formed  (ptomains  and  al- 
lied substances)  by  the  organisms  Avhich 
act  as  irritants  to  the  vital  tissues,  until, 
when  the  apical  hut  still  vital  portions 
of  the  pulp  become  the  soil  for  the  de- 
velopment of  pyogenic  organisms,  the 
tissues  of  the  apical  region  are  affected. 
Usually  in  the  later  stages  of  pulp  sup- 
puration the  tooth  becomes  sensitive  upon  percussion.  Succeeding  this 
state  of  affairs  is  a  period  of  delusive  quiet,  during  which  the  apical 
tissues,  although  doubtless  aifected  by  the  toxic  substances  present, 
exhibit  but  slight  subjective  symptoms.  The  remnants  of  the  pulp  are 
undergoing  progressive  decomposition,  as  are  also  the  contents  of  the 
dentinal  tubules.  After  a  variable  period,  governed  by  the  virulence 
of  the  organisms  present  and  the  inherent  resistance  of  the  vital  tissues 
of  the  ajneal  region,  these  latter  succumb,  poisoned  by  the  toxic  sub- 
stances formed  in  contact  with  them,  and  an  inflammatory  action  arises ; 
this  may  be  sul)acute,  evidenced  by  sensitiveness  upon  percussion  and  a 
deepening  of  the  gum  color  overlying  the  apex  of  the  root,  constituting 
a  condition  known  as  subacute  pericementitis  ;  or,  if  the  attack  be  more 
severe,  or  the  resistance  lessened,  the  symptoms  are  more  violent ;  there 
is  a  pronounced  hyperemia,  quickly  succeeded  by  the  evidences  of 
marked  inflammatory  action.  The  tooth,  owing  to  the  eflPusions  in  the 
pericementum,  becomes  elevated  and  exquisitely  sensitive  to  touch  ; 
the  color  of  the  gum  deepens,  and  heavy  throbbing  pain  is  complained 
of;  acute  pericementitis  is  in  progress.  In  more  severe  cases  marked 
^  See  Chapter  XX.  on  Bleaching. 


THERAPEUTIC  AGENTS.  433 

oedema  of  the  gum  and  it  may  be  of  the  face  arises  ;  tlie  pulse  increases 
in  volume,  tension  and  frequency  ;  febrile  action,  with  a  temperature  as 
high  as  103°  or  104°  may  occur ;  in  other  cases  distinct  evidences  of 
septic  intoxication  may  appear,  and  indeed  even  septicemia  or  pyemia  ^ 
may  result  at  a  later  stage. 

The  severity  of  the  inflammatory  action  is  no  doubt  governed  in  part 
by  the  variety  of  the  infecting  organisms,  and  again  by  the  physical 
condition  of  the  individual  attacked.  Judging  from  the  mode  of  prog- 
ress and  attack,  the  staphylococci  are  the  offenders  where  the  inflam- 
matory action  is  circumscribed,  and  the  streptococci  in  cases  which 
exhibit  a  tendency  to  spread  along  the  course  of  the  fascia  and  produce 
phlegmonous  inflammation.^  Schreier  has  found  the  almost  invariable 
presence  of  a  diplococcus  in  this  condition,  probably  the  diplococcus 
pneumonice. 

Individuals  presenting  any  of  the  several  manifestations  of  struma, 
inherited  or  acquired,  suffer  from  a  debility  of  general  vital  processes, 
and  may  have  the  inflammatory  action  run  a  riotous  course  (see 
Alveolar  Abscess,  Chapter  XVIII.).  As  a  rule,  when  a  tooth  has  been 
the  seat  of  subacute  pericementitis  for  a  lengthened  period,  or  of  acute 
septic  pericementitis  for  from  twenty-four  to  forty-eight  hours,  there  is 
more  or  less  death  of  cellular  elements  in  the  inflammatory  effusion, 
pus  forms,  and  alveolar  abscess  is  established  (see  Chapter  XVIII.). 

In  cases  of  subacute  pericementitis,  even  those  in  which  pus  forma- 
tion is  not  evident,  the  tissues  of  the  apical  region  are  assailed  by  the 
products  of  putrefactive  decomposition,  which  latter  process  may  prove 
difficult  to  overcome,  the  tissues  rebelling  at  each  attempt  to  close  the 
outlet  to  the  escape  of  gases  Avhich  irritate  them. 

Each  phenomenon  mentioned  as  accompanying  the  stages  of  septic 
infection  and  albuminous  decomposition  forms  an  item  for  consideration 
in  the  therapeutic  measures  to  be  applied. 

Therapeutic  Agents. 

The  natural  and  true  inference  from  w4iat  has  been  stated  is  that  the 
class  of  therapeutic  agents  to  be  locally  employed  in  any  of  these  condi- 
tions are  all  included  under  the  general  order  of  germicides,  antisejitics, 
and  disinfedaiifs. 

The  one  distinguishing  feature  that  all  of  these  substances  have  in 
common  is  the  power — differing  in  degree  in  each — of  destroying  patho- 
genic organisms  or  rendering  innocuous  their  waste  products ;  their 
other  properties  differ  widely,  so  that  the  agent  for  application  to  spe- 

^  See  case  of  Dr.  E.  T.  Darby,  Proc.  Odontological  Society  of  Pennsylvania,  1892. 
^  See  case  reported  by  Dr.  E.  C.  Kirk,  Proc.  Odontological  Society  of  Pennsylvania, 
1892. 

28 


434  THE  TREATMENT  AND  FILLING   OF  ROOT  CANALS. 

cific  disease  conditions  is  selected  with  a  regard  to  which  shall  best  and 
most  completely  attain  a  definite  end.  According  to  the  effects  prodnced 
n])()n  ali)umin  the  agents  under  consideration  may  be  placed  in  two 
classes,  coagulants  and  non-coagulants.  In  the  former  class  are  in- 
cluded salts  of  the  metals  and  alcohols ;  in  the  latter,  many  of  the 
essential  oils. 

Mineral  acids  and  the  alkalies  act  by  chemically  destroying  the 
albumin.  The  metallic  salts  which  have  been  employed  or  tested  as 
germicides  in  pulp  canals  are  the  chlorids  of  zinc  and  of  aluminum,  the 
bichlorid  of  mercury,  the  bichlorid  of  gold  and  sodium,  the  sulfate  of 
copper,  and  the  nitrate  of  silver.  The  salts  of  copper,  silver,  and  gold 
are  not  adapted  on  account  of  the  discolorations  produced  by  them. 
Mercuric  chlorid  is  open  to  the  same  objection  ;  thus  the  only  metallic 
salt  having  general  application  is  zinc  chlorid. 

The  alcohols  employed  are  the  ethylic  (commercial)  alcohol ;  phenylic 
alcohol,  i.  e.  carbolic  acid,  and  creosote,  with  the  coal-tar  derivatives, 
the  cresols.  In  this  connection  formalin — a  40  per  cent,  solution  of  the 
gas  formaldehyd  in  water  should  be  mentioned  very  favorably ;  in 
dental  practice  it  is  reduced  to  a  strength  of  3  to  5  per  cent. 

Preparations  of  iodin,  bromin,  and  chlorin  are  all  powerful  anti- 
septics and  disinfectants.  Bromin  is  inapplicable  owing  to  its  irritat- 
ing effects  and  offensive  odor ;  chlorin  is  employed  in  the  form  of 
hypochlorites ;  usually  in  the  solutions  called  electrozone  and  mcditrina, 
electrolytic  products  of  sea-water.  Labarraque's  solution  of  sodium 
hypochlorite  appears  to  have  fallen  into  general  disuse,  as  have  also  the 
hyposulfites.  The  usual  form  in  which  iodin  is  applied  is  as  the 
tincture.  Iodin  trichlorid  is  said  ^  to  be  five  times  as  strong  as  mercuric 
chlorid  as  an  antiseptic. 

The  essential  oils  recommended  as  antiseptics  for  employment  in 
canal  and  dentin  sterilization  are  those  of  thyme,  cinnamon,  cassia, 
myrtle,  and  eucalyptus. 

The  alkalies  employed  as  sterilizing  agents  are  Schreier's  alloy  of  po- 
tassium and  sodium,  called  Kalium-natrium  ;  sodium  carbonate  and  so- 
dium dioxid.  The  mineral  acids  which  have  been  recommended  are  hydro- 
chloric and  sulfuric,  the  latter  by  the  method  described  by  Dr.  Callahan.^ 

The  gases  oxygen  and  chlorin,  in  statu  nascendi,  are  employed  as 
sterilizing  agents,  the  former  extensively.  When  these  are  applied  as 
bleaching  agents,  the  sterilization  is  coineidently  accomplished,  as 
pointed  out  in  the  chapter  on  Bleaching. 

Oxvgen  is  liberated  from  aqueous  and  ethereal  solutions  of  hydrogen 
dioxid  and  solutions  of  sodium  dioxid. 

^  Langenbach,  quoted  by  Miller,  Dental  Cosmos,  vol.  xxxiii.  p.  342. 
2  Proc.  Ohio  State  Dental  Society,  1894. 


THERAPEUTIC  AGENTS.  435 

lodol,  iodoform,  and  kindred  substances  are  not  employed  as  germi- 
cides per  se,  but  for  other  therapeutic  properties  possessed  by  them,  e.  g. 
their  supposed  capability  of  maintaining  sterilization  after  the  more 
powerful  antiseptics  have  been  employed  as  germicides. 

Aristol,  dithymol  biniodid,  is  another  member  of  this  group,  which 
owing  to  its  chemical  composition  is  theoretically  preferable  to  the 
others.  It  contains  twice  the  quantity  of  iodin  in  loose  combination, 
and  in  addition  has  as  its  base  a  powerful  antiseptic,  thymol. 

These  agents  are  supposed  to  act  as  antiseptics  in  consequence 
of  setting  free  iodin  when  brought  in  contact  with  albuminous 
substances. 

It  has  been  demonstrated  that  iodoform  is  not  a  germicide  (organ- 
isms growing  about  it),  but  it  appears  to  lessen  or  destroy  the  eifects 
of  toxic  substances  generated  about  it  as  the  result  of  albuminous  de- 
composition. 

The  final  antiseptic  to  be  mentioned  is  the  mechanical  removal  of 
infected  tissues. 

Zinc  chlorid  forms,  when  brought  in  contact  with  albumin,  a  dense 
and  almost  colorless  coagulum  of  zinc  albuminate.  Placed  at  one  end 
of  a  capillary  tube  containing  albumin,  it  diffuses  rapidly  through  the 
solution,  coagulating  it  throughout. ' 

Carbolic  acid  forms  less  dense  coagula,  and  creosote  still  less. 
Mercuric  chlorid  and  silver  nitrate  form  complete  coagula  also.  It  may 
be  well  in  this  connection  to  call  attention  to  an  observation  made  by 
Dr.  Kirk,  in  an  essay  read  before  the  First  District  Dental  Society  of 
New  York,  that  coagulation  is  a  chemical  process,  as  illustrated  in  the 
union  of  mercuric  chlorid  with  albumin.  The  metallic  salt  does  not 
act  by  catalysis,  but  there  is  a  distinct  quantitative  relation  between  the 
coagulant  and  the  coagulable  material,  the  process  ceasing  when  the 
quantitative  relation  of  these  bodies  is  chemically  satisfied ;  if  an  excess  of 
HgClo  be  employed,  a  definite  amount  of  the  salt  combines  with  albumin 
to  form  an  albuminate  of  mercury  suspended  in  a  solution  of  the  cliemical 
excess  of  HgCU.  If  an  excess  of  the  albumin  be  employed,  an  albumin- 
ate of  mercury  is  formed  suspended  in  a  solution  of  albumin.  The  albu- 
minate of  mercury  when  brought  in  contact  with  an  easily  decomposable 
sulfur  compound  may  be  reduced  by  the  formation  of  mercury  sulfid 
and  the  albumin  be  restored  to  its  primary  condition,^  which  would 
seem  to  indicate  that  HgCla  is  an  unreliable  germicide  where  putrefac- 
tive decomposition  is  in  progress  giving  rise  to  HjS. 

Formalin  readily  and  quickly  aifects  both  albumin  and  gelatin,  con- 
verting them  into  a   tough  coagulum   which    maintains   its   form   and 

^  Prof.  James  Truman,  Proc.  Academy  of  Stomatology  of  Philadelphia,  Dec.  1894. 
'^Abbott,  Principles  of  Bacteriology,  3d  ed.,  1896. 


436  THE  TREATMENT  AND  FILLING   OF  ROOT  CANALS. 

appears  to  be  persistently  antiseptic  for  certain  varieties  of  micro- 
organisms. 

The  essential  oils  act  as  antiseptics  without  coagulation,  having 
markedly  less  germicidal  action  than  the  agents  above  mentioned. 
Placed  in  root  canals  they  diffuse  througli  the  dentin,  maintaining  a 
prolonged  antiseptic  influence  ;  their  absorption  into  the  dentin  pro- 
duces some  degree  of  discoloration  in  that  tissue.  These  oils  differ  in 
antiseptic  power.  Oil  of  thyme  and  oil  of  cinnamon  stand  at  tlu;  head 
of  the  list,  oil  of  cloves  and  eucalyptus  being  far  below  them  in  the 
antiseptic  scale. 

The  alkalies  employed  as  antiseptics  saponify  the  fatty  matters  formed 
in  the  course  of  albuminous  decomposition,  and  dissolve  albuminous 
substances  with  which  they  are  brought  in  contact.  The  first  of  these, 
the  alloy  of  potassium  and  sodium,  when  placed  in  contact  with  decom- 
posing pulp  tissue,  abstracts  the  elements  of  water  from  it,  and  sodium 
and  potassium  hydroxids  are  formed,  which  have  the  power  of  saponi- 
fying fats  and  dissolving  all^umins.  Sodium  carbonate  has  similar 
properties,  but  acts  less  energetically.  Sodium  dioxid  under  the  same 
conditions  forms  sodium  hydroxid,  nascent  oxygen  being  set  free,  which 
acts  as  a  germicide  and  also  decomposes  the  coloring  substances  in  the 
dentinal  tubules,  acting  as  a  bleaching  agent  to  the  dentin.  Solutions 
of  hydrogen  dioxid  are  decomposed  into  water  and  nascent  oxygen  in 
contact  with  the  putrescent  canal  contents  ;  the  liberated  oxygen  acting 
as  an  oxidizer. 

Tiie  mineral  acids  when  employed  subserve  a  double  office.  Sul- 
furic acid  placed  at  the  mouth  of  fine  canals  unites  with  and  decom- 
poses the  calcium  salts  of  the  dentin,  forming  calcium  sulfate,  easily 
removable  with  the  fine  canal  scrapers  ;  its  second  office  is  that  of  an 
effective  germicide,  destroying  all  organisms  with  which  it  is  brought 
in  contact. 

Materials  for  Filling  the  Root  Canal. 

The  materials  employed  to  hermetically  seal  the  apical  foramina  of 
sterilized  canals  are  in  the  condition  of  solids  inserted  en  masse  or  in 
successive  portions ;  or  they  are  pastes  applied  alone,  or  upon  some 
medium  which  acts  as  a  vehicle.  Another  class  are  ordinarily  solid,  but 
are  brought  to  a  condition  of  fluidity  before  inserting  them. 

The  properties  which  should  be  possessed  by  a  satisfactory  canal  filling 
are  as  follows  :  Impermeability — it  should  hermetically  seal  the  apical 
foramen,  effectually  preventing  the  egress  of  pathogenic  organisms  or 
their  waste  products  from  the  canals  to  the  tissues  of  the  apical  region 
and  vice  versa,  and  it  should  prevent  transudations  from  the  apical 
tissues  into  the  pulp  canals.     It  should  be  unchanged  by  the  influences 


MATERIALS  FOR  FILLING   THE  ROOT  CANAL.  437 

about  it ;  be  iinirritating  to  the  soft  tissues ;  and  possess  sufficient 
plasticity  to  permit  of  its  ready  adaptation  to  the  walls  of  the  space  it  is 
desitjned  to  till.  It  should  be  at  least  aseptic  when  applied,  and  pref- 
erably antiseptic  :  it  is  to  be  esteemed  in  the  degree  that  it  maintains 
this  latter  quality  in  combination  with  the  other  desiderata  stated. 

The  solid  materials  which  have  been  employed  for  this  purpose  are 
gold  foil,  shredded  tin  foil,  gold,  copper  and  lead  points  ;  wood  points 
dipped  in  creosote  have  been  used  for  this  purpose.  The  readily  oxi- 
dizable  metals  have  not  found  favor  owing  to  the  possibility  of  dentinal 
staining  following  their  employment.  The  plastic  materials  employed 
are  softened  gutta-percha  cones  and  the  zinc  oxychlorid  cement.  The 
latter  and  also  other  pastes  are  frequently  employed  to  fill  the  meshes 
of  a  wisp  of  crude  cotton  wool  or  asbestos  fiber,  these  latter  being  the 
vehicle  for  carrying  the  paste  into  position.  It  is  to  be  remembered 
that  when  cotton  fiber  is  kept  in  prolonged  contact  with  zinc  chlorid, 
the  cellulose  undergoes  a  chemical  change  :  it  is  converted  into  a  pectous 
substance  called  amyloid,  which  is  a  colorless  colloid,  unchangeable  in 
the  conditions  existing  at  the  apex  of  a  pulp  canal. 

Cotton  itself  may  be  included  among  the  plastic  root  fillings. 

The  fluid  substances  employed  are  solutions  of  red  gutta-percha 
base  plate  in  chloroform,  the  solution  called  chloro-percha,  which  con- 
tains in  this  case  vermilion  ;  if  made  of  white  gutta-percha  it  contains 
zinc  oxid  and  a  variable  amount  of  other  mineral  substances.  The 
other  members  of  this  class  are  salol  and  paraffin,  made  fluid  by  heat 
before  insertion  and  becoming  hard  when  cool. 

Gold  was  the  first  material  adopted  for  the  purpose  of  canal  filling, 
being  introduced  in  this  connection  by  Dr.  Maynard  over  fifty  years 
ago.  Properly  adapted  it  may  be  made  to  hermetically  seal  the  apical 
foramen.  It  is  difficult  to  manipulate,  and  its  removal  after  the  type  of 
adaptation  required  is  wellnigh  impossible.  Tin  has  the  same  virtues 
and  is  open  to  the  same  objection,  which  in  fact  obtains  when  any  metal 
is  forcibly  driven  into  the  apical  portion  of  the  canal.  It  is  held,  how- 
ever, and  with  a  measure  of  good  reason,  by  those  who  advocate  the 
em})loymcnt  of  metal  for  this  purpose,  that  when  a  pulp  canal  has  been 
thoroughly  sterilized  and  filled,  the  necessity  for  the  removal  of  the  root 
filling  will  never  arise.  The  degree  of  confidence  expressed  in  this  opinion 
has  not  yet  served  to  override  the  caution  of  the  conservative  operator, 
so  that  metals  have  an  extremely  limited  employment  in  this  connection. 

The  plastic  materials  most  frequently  recommended  and  which  sta- 
tistics and  general  experience  demonstrate  to  serve  most  acceptably  as 
canal  fillings,  are  the  oxychlorid  of  zinc  and  gutta-percha. 

The  zinc  cement  when  in  paste  form  may  be  readily  adapted  to  any 
accessible  canals,  and  it  maintains  during  and  for  some  time  after  set- 


438  THE  TREATMENT  AND  FILLING    OF  ROOT  CANALS. 

ting  an  antiseptic  action.  The  pecnliar  and  specific  inflncnce  exerted 
by  this  niatenal  npon  the  alhnminons  constituents  of  the  tooth  may  be 
seen  as  a  not  infrequent  sequel  to  its  emph)ynient  as  a  pidp  capj)ing. 
Many  of  sucli  teeth  whose  pulp  chambers  have  been  opened  some  years 
after  the  capjnng  operation  are  found  to  have  had  their  pulps  changed 
to  a  dry  tough  mass  which  has  not  been  the  seat  of  septic  invasion  ; 
moreover,  the  normal  color  of  the  dentin  of  such  teeth  has  been  main- 
tained, showing  that  no  extensive  chemical  decomposition  has  occurred 
in  the  contents  of  the  tubules.  As  a  canal  filling  it  becomes  very  hard, 
remains  white,  and  when  freshly  mixed  is  markedly  irritating  to  vital 
tissue  with  which  it  is  brought  in  contact.  Its  removal  Avhen  indicated 
may  be  accomplished  by  repeated  applications  of  sulfuric  acid  after  the 
Callahan  method  of  opening  canals. 

When  the  meshes  of  cotton  are  filled  with  the  paste  made  thin,  the 
zinc  chlorid  acts  upon  the  cotton,  converting  it  into  amyloid  ;  so  that 
if  a  pellet  of  cotton  moistened  with  a  sedative  antiseptic  be  placed  in 
the  apical  portion  of  a  root  canal  and  the  thin  paste  placed  over  it,  the 
filling  of  the  apex  after  the  chemical  action  noted  consists  of  the  un- 
changeable impervious  amyloid  and  not  of  cotton. 

Long  thin  gutta-percha  cones  are  readily  made  plastic,  but  the 
adaptation  of  the  material  to  the  walls  of  the  canal  is  less  intimate  than 
is  that  of  the  oxychlorid  of  zinc.  It  is  unchangeable  in  the  conditions 
under  which  it  is  placed,  and  is  the  most  bland  and  unirritating  of 
filling  materials.  Its  removal  after  proper  placement  is  difficult  but  by 
no  means  impossible.  The  gutta-percha  compound  known  as  temporary 
stopping  has  similar  properties,  but  is  less  tough  in  texture. 

The  last  of  the  plastics  introduced  is  a  resinous  substance  called  the 
bahamo  del  descrto.  It  is  probably  an  exudation  from  one  of  the 
varieties  of  pine  or  fir.  Its  virtues  and  employment  were  first  described 
by  Dr.  W.  H.  White  of  Silver  City,  N.  M.  His  experiments  indicate 
that  the  resin  has  a  ])ronounced  antiseptic  action  ;  it  adheres  to  wet 
surfaces,  and  is  perfectly  non-irritating  to  soft  tissues  with  which  it  is 
brought  in  contact.  It  remains  unchanged  when  employed  as  a  canal 
dressing.  He  finds  that  the  roots  of  temporary  teeth  which  have  been 
filled  with  the  material  suffer  no  interference  with  the  resorption  process 
because  of  its  presence. 

Thin  solutions  of  gutta-percha  in  chloroform  (chloro-percha)  have 
wide  employment  as  fillings  for  fine  and  tortuous  root  canals.  These 
solutions  may  be  carried  into  any  canal  which  will  admit  the  finest 
broach.  They  shrink  in  hardening,  so  that  a  canal  filling  of  such  a 
solution  does  not  hermetically  seal  the  cavity  when  the  material  is 
hardened. 

The  solution  is  usually  employed   in   combination  with  the  gutta- 


MUMMJFICATION  OF  THE  PULP.  439 

percha  cones.  Dr.  K.  Ottolengui "  recommends  a  method  which  may 
be  followed  with  advantage  :  A  number  of  piews  of  floss  silk  about  an 
inch  long  are  saturated  with  chloro-percha  and  dried  ;  these  are  then 
thrust  in  a  chloro-percha  canal  filling  while  it  is  fluid.  Should  it  ever 
become  necessary  to  remove  the  filling,  the  projecting  end  of  one  of  the 
pieces  of  silk  is  caught,  and  the  entire  filling  may  be  withdrawn. 

The  use  of  salol  in  this  connection  was  first  described  and  advocated 
by  Dr.  Mascort  of  Paris.-  Salol,  the  salicylate  of  phenol,  is  mildly 
antiseptic.  When  brought  into  contact  with  alkalies  it  is  decomposed 
into  carbolic  and  salicylic  acids,  two  powerful  antiseptics.  It  melts  at 
40°C.  (104°r.),  and  if  fused  at  or  but  little  above  this  heat  it  crys- 
tallizes in  a  few  minutes  ;  if  the  heat  be  raised  to  a  higher  point  crystal- 
lization is  delayed  for  some  time  after  the  mass  has  cooled  far  below  its 
normal  melting-point.  The  melted  salol  may  be  readily  carried  into  anv 
canal  which  will  admit  the  finest  broach.  P<u*tions  of  the  material  which 
may  be  carried  beyond  the  apical  foramen  appear  to  be  unirritating. 

Reports  as  to  the  permanence  and  value  of  this  material  vary  from 
enthusiastic  endorsement  to  unqualified  condemnation.  Many  of  those 
who  have  used  salol  have  found,  upon  reopening  canals  which  have 
been  filled  with  it,  an  absence  of  the  salol ;  however,  where  the  practice 
has  been  to  employ  a  central  canal  filling  of  gutta-percha,  a  cone  of 
which  material  is  thrust  into  the  melted  salol,  in  such  cases  its  absence 
has  not  been  observed.  Salol  has  been  found  to  suffer  rapid  decomposi^ 
tion  in  canals  which  have  been  treated  with  one  of  the  fixed  alkalies 
just  before  the  salol  was  inserted. 

Paraffin  has  been  employed  for  a  canal  filling,'made  fluid  by  heat  and 
carried  into  the  canals  ;  it  is  bland,  unirritating,  unchangeable,  and  easily 
removable.^     It  may  be  used,  mixed  with  aristol,  in  sterilized  canals.* 

Before  discussing  the  cleansing  of  pulp  canals,  certain  means  and 
methods  suggested  for  avoiding  the  necessity  for  the  toil  and  care 
necessary  to  mechanically  cleanse  the  more  inaccessible  canals  require 
consideration.     These  agents  are  preservative  pastes. 

Mummification  of  the  Pulp. — As  early  as  the  introduction  of 
arsenous  oxid  as  a  devitalizing  agent  it  was  noted  that  a  certain  per- 
centage— or  rather,  an  uncertain  percentage — of  cases  gave  evidence  of 
little  or  no  disease  after  the  application  of  arsenic  and  its  sealing  in  a 
cavity  by  a  filling.  Later,  it  was  found  that  applications  of  powerful 
antiseptics  to  exposed  pulps  not  infrequently  were  followed  by  a  long- 
continued  quiet  of  that  organ  ;  still  later,  when  more  definite  knowledge 
was  possessed  of  the  pathological  results  which  might  follow  the  leaving 
of  portions  of  pulp  substance  in  the  canals  of  teeth  after  devitalization 

1  Methods  of  FiUinxj  Teeth.  2  Dental  CUmos.  1S94,  p.  352. 

^  Ibid.  *  Ibid.,  June  181)7. 


440  THE  TREATMENT  AND  FILLING   OF  ROOT  CANALS. 

by  arsenic,  it  was  ol^scrvcd  that  after  saturatino;  the  canals  with  creosote 
or  zinc  chh)ri(l  sohitions,  many  cases  gave  little  or  no  evidence  of  peri- 
cemental distnrbance  thereafter. 

While  it  is  unquestionably  preferable  to  always  thoroughly  remove 
the  last  vestige  of  devitalized  pulps,  the  time,  care,  skill,  and  expense 
involved  in  perfect  cleansing  are  detriments  to  its  universal  practice. 
The  only  other  possible  solution  of  the  difficulty  is  to  so  alter  the  tissue 
not  removed  that  it  shall  remain  permanently  aseptic,  and,  if  possible 
to  make  it  so,  antiseptic. 

Observations  derived  from  clinical  experience,  although  undoubtedly 
of  great  and  permanent  value,  are  indeterminate,  and  our  truly  scientific 
knowledge  of  this  matter  dates  from  Dr.  W.  1).  Miller's  experiments.^ 
He  credits  Dr.  Witzel  with  the  first  systematic  observations  in  this 
direction.  Dr.  Witzel  in  1874,  "devitalized  the  crown  portion  of  pulps 
by  means  of  arsenic,  extirpated  that  portion  leaving  the  pulp  in  the 
canals  undisturbed,  their  exposed  ends  being  treated  as  freshly  exposed 
pulps."  This  is  the  method  followed  by  Herbst,  who  employs  cobalt 
(which  is  native  arsenic  sulfid  or  metallic  arsenic)  instead  of  arsenic 
trioxid. 

Dr.  Miller's  experiments  have  shown  that  none  but  the  most  power- 
ful and  penetrating  antiseptics  have  value  as  permanent  sterilizers. 
These  are  :  The  cyanid,  bichlorid,  and  salicylate  of  mercury,  sulfate 
of  copper,  and  oil  of  cinnamon.  Orthocresol,  carbolic  acid,  trichlor- 
phenolj  and  zinc  chlorid  penetrate  the  pulp  tissue  rapidly,  but  are  too 
difiusible,  disappearing  in  a  few  weeks. 

He  classifies  salicylic  acid,  eugenol,  campho-phenique,  hydronaphthol, 
a-  and  ^5-naplithol,  acetico-tartrate  of  aluminum,  and  some  essential  oils, 
resorcin,  thallin,  sulpho-carbolate  of  zinc,  etc.,  as  being  of  doubtful 
value. 

Those  nearly  or  quite  w^orthless  are  iodoform,  basic  anilin  coloring 
matters,  borax,  boric  acid,  dermatol,  europhen,  calcium  chlorid,  hydro- 
gen dioxid,  sozoiodol  salts,  tincture  of  iodin,  spirit  of  camphor,  and 
naphthalin. 

The  preparation  giving  the  best  results  consisted  of — ^Mercuric  chlo- 
rid, 0.0075  gram  ;  thymol,  0.0075  gram,  in  tablet  form. 

The  pulp  is  devitalized  ;  the  crown  portion  and  all  the  root  portion 
readily  accessible  is  removed  ;  one  of  the  tablets  is  placed  in  the  pulp 
chamber,  crushed  by  means  of  an  amalgam  plugger,  and  covered  with 
gold  foil.  The  mercury  salt  tends  to  discolor  the  crown  of  the  to(jth, 
so  that  its  employment  should  be  restricted  to  the  posterior  teetli ; 
indeed,  the  necessity  for  its  use  would  be,  as  a  rule,  found  with  these 
teeth,  being  those  from  which  it  is  most  difficult  to  extract  pulp  rem- 

^  Proc.  Columbian  Dental  Congress,  1893. 


MUMMIFICATION  OF  THE  PULP. 


441 


nants.  Dr.  Miller  expresses  faith  in  the  power  of  oil  of  cinnamon  to 
permanently  sterilize  pulp  fragments.  He  suggests  the  experimental 
application  of  the  sterilizing  tablets  to  such  teeth  as  are  readily  sal- 
vable  yet  which  are  for  various  reasons  "  consigned  to  the  forceps." 
Dr.  Theodore  Soderberg  of  Sydney,  X.  S.  AV.,  reports  excellent 
results  from  a  continuous  practice  of  this  variety  of  pulp  sterilization. 
He  employs  a  paste  composed  of — 


^.  Alum  exsic, 
Thymol, 
Glycerol, 
Zinc  oxid. 


da.  3j  ; 
q.  s.  to  make  stiff  paste. — M. 


It  will  be  noted  that  he  substitutes  dried  alum  for  tannin,  originally 
used  by  him  as  the  hardening  agent :  his  experiments  showed  the 
tannin  to  be  productive  of  discoloration.  INIercuric  chlorid  is  set  aside 
for  the  same  reason.  Oil  of  cassia  employed  in  the  paste  also  caused 
discoloration.  At  present  Dr.  Soderberg  adds  a  small  quantity  of 
cocain  to  the  paste  to  prevent  the  pain  arising  from  the  action  of  the 
dried  alum.  He  states  (Nov.  1895)  that  he  has  in  a  year  applied  the 
paste  in  97  cases  and  has  had  no  untoward  results.  The  method  of 
jslacing  the  material  is  shown  in  Figs.  399,  400. 


Fig.  399. 


Fig.  400. 


a,  Caries  exposing  a  horn  of  the  pulp. 


a,  Root  portion  of  pulp  ;  b,  mummifying  paste ; 
c,  zinc  phosphate  ;  d,  gold  or  amalgam. 


C.  A.  Firth  of  Queenleyan,  N.  S.  W.,^  advises  the  omission  of 
zinc  oxid  from  the  paste,  to  avoid  the  formation  of  the  brown  tannate 
of  zinc.  He  suggests  the  use  of  a  mixture  of  tannic  acid  and  thymol 
equal  parts,  made  into  a  paste  with  glycerol  and  ajiplied  with  ivory 
instruments,  to  avoid  di.^colorations.  He  expresses  him.'^clf  as  gratified 
at  the  results  obtained.    Another  formula  suuirosted  bv  the  same  gentle- 


man is- 


1  Lental  Cosmos,  Mav,  1896. 


442  THE  TBEATMEyT  AND  FILLING   OF  BOOT  CANALS. 


DESCRIPTION  OF  FIGS.   401,  402,  AND  408.^ 

Fig.  401.— Fig.  3  gives  in  contrast  a  sectional  view  of  deciduous  and  permanent  upper  teeth 
divided  tlirough  their  lateral  diameters. 

Fig.  4,  a  sectional  view  of  the  corresponding  lower  teeth  divided  through  their  antero-posterior 
diameters,  a,  b,  c  represent,  respectively,  the  deciduous  and  permanent  front  incisors  in  con- 
trast: d,  e,f,  the  lateral  incisors  ;  g,  h,  i,  the  canines;  k,  deciduous  molars,  upper  and  lower;  and 
l,m,  the  successors  to  the  deciduous  molars,  the  bicuspids;  n,  n  represent  permanent  molars, 
c,/,  i,  m,  o  have  dotted  lines  indicating  the  thickness  of  enamel  removed  by  wear,  atrophy  of  the 
cementum,  and  reduction  in  the  size  of  the  pulp  due  to  progressive  calcification,  these  changes 
being  incident  to  old  age. 

Fig.  402  represents  in  Fig.  1,  letters  a  to  h  and  a  to^,  the  longitudinal  or  vertical  sections  of 
the  sixteen  upper  teeth,  showing  the  labio-palatal  diameter  of  the  pulp  chamber  and  canal  in 
crown  and  roots,  the  section  of  the  molars  being  through  the  anterior  buccal  and  palatal  roots, 
while  the  bicusjiids  d  e  and  d_e  illustrate  the  result  of  such  a  compression  of  the  root  as  to 
divide  the  pulp  chamber  into  two  canals— a  condition  which  so  frequently  exists  in  these  flattened 
roots.  The  double-lettered  series,  d  d  to  h  h  and  d  d  to  hh,  represent  in  the  molars  a  section 
through  the  posterior  buccal  and  the  palatal  roots,  from  whicla  is  quite  readily  recognized  the 
slightly  greater  lateral  diameter  of  the  pulp  chamber  in  the  crown  and  the  larger  canal  in  the  poste- 
rior buccal  root  over  that  in  the  anterior  buccal  root,  while  the  bicuspids  lettered  eedd  and  ddee 
illustrate  a  modified  pulp  chamber  and  canal,  with  bifurcation  of  the  root  in  one,  these  being  cut 
tlirough  a  different  axis  or  plane  from  the  single-lettered  series. 

Fig.  2,  letters  a  to  h  and  a_  to  h_,  represent  the  sixteen  lower  teeth  with  the  section  through 
their  long  diameters,  as  in  the  upper  series.  These  incisors  illustrate  the  compressed  or  flat- 
tened condition  of  their  roots  in  contrast  with  the  cylindrical  character  of  the  roots  of  the  upper 
incisors,  while  the  bicuspids  d  e  and  d_e  illustrate  the  singleness  of  their  pulp  chamber  and  the 
cylindrical  condition  of  their  roots  as  in  contrast  with  the  flattened  or  compressed  condition  of 
the  roots  of  the  upper  bicuspids.  The  molars  /,  g,  h  and  f,  g.  h  represent  sections  through  the 
anterior  root,  illustrating  its  compressed  condition  and  divided  pulp  chamber  in  the  first  and 
second  molar,  and  a  somewhat  flattened  one  in  the  anterior  root  of  the  third  molar ;  //,  g  g  ,  h  h 
and  //,  g  g,  h  h  represent  the  single  and  cylindrical  pulp  chamber  in  the  posterior  root  of  the 
lower  molars,  while  bb,  ce  and  aa.bb  represent  the  incisors  and  canines  of  the  same  series,  with 
modified  pulp  chambers  arising  from  modified  development. 

Fig.  403.— Fig.  1,  from  a  to  h  and  a,  to _^  represents  the  upper  teeth,  with  transverse  or  horizon- 
tal section  through  the  base  of  the  pulp  chamber  in  the  crown,  viewing  the  entrance  to  the  canals 
of  the  several  roots,  while  the  same  letters  in  Fig.  2  represent  the  lower  series  in  the  same 
manner. 

Fig.  3  represents  the  upper  teeth,  with  the  transverse  or  horizontal  section  made  below  the 
largest  diameter  of  the  pulp  chamber  and  through  the  canals  after  they  have  diverged  from  the 
central  chamber,  but  before  the  roots  into  which  they  run  have  in  the  molars  bifurcated. 

Fig.  4  in  like  manner  represents  the  lower  series,  well  illustrating  the  flattened  or  compressed 
condition  of  the  canal  in  anterior  roots  of  the  molars  and  the  division  of  the  chamber,  as  is  fre- 
quently found  in  the  roots  of  the  lower  incisors. 

The  letters  aa,bb,cc,d  d,ff,  dd.  and^  (Fig.  3)  represent  the  relative  shapes,  whether  circu- 
lar, oval,  or  flattened,  of  the  pulp  canal  in  the  roots  of  the  upper  central  and  lateral  incisors, 
the  canines,  the  first  and  second  bicuspids,  and  the  first,  second,  and  third  molars,  while  the 
same  letters  in  Fig.  4  represent  the  relative  shapes  of  the  pulp  canal  in  similar  teeth  in  the 
lower  series. 

1  These  figures  are  taken  from  v.  Carabelli's  Anatomie  des  Mundes. 


Fig.  401. 
(For  description,  see  page  442.) 


443 


Fig.  402. 
(For  description,  see  page  442.) 


444 


Fig.  403. 
(For  description,  see  page  412.) 


""Vi 


dL 


.// 


^^ 


^j^ 


^^ 


D^ 


&^    £*. 


// 


tc 


IftJ^^* 


V 


i^\ 


£«■ 


445 


446  THE  TREATMENT  AND  FILLING    OF  ROOT  CANALS. 

I^.  Mercuric  chlorid,  ^ 

Thymol,  V  da.  2.0  grams ; 

Acid,  carbolic,      j 

Acid,  tannic,         \ 

T\T       1  I  «''•  l-'5  gram  ; 

Morph.  mur.,         J  ^         ' 

Ol.  menth.,  I  ,        .«> 

^,  .  >  aa.  q.s.  to  make  stin  paste. — M. 

Ol.  cassise,  j  ^  ' 

"A  tannate  of  mercury  is  formed;  it  is  insoluble,  and  but  little  pain 
is  caused  by  its  absorption." 

It  is  to  be  understood  that  these  preparations  and  this  method  of 
pulp  preservation  are  only  to  be  utilized  when  reasons  exist  which 
would  preclude  the  perfect  cleansing  and  filling  of  canals.  These 
reasons  may  be  economic  or  the  impracticability  of  thoroughly  extir- 
pating all  pulp  remnants.  Failing  in  perfect  extirpation,  the  paste  is 
to  be  packed  into  parts  where  the  irremovable  pulp  remnants  exist. 

Quite  recently  formalin  and  its  isomeric  modification  paraform 
have  been  suggested  for  use  as  mummifying  agents,  with  some  promise 
of  satisfactory  results,  but  these  substances  are  still  in  the  stage  of  ex- 
perimental study.  The  irritating  nature  of  formalin  suggests  caution  in 
its  permanent  application  to  pulps  or  pulp  canals,  as  several  cases  of 
chemical  necrosis  of  tissues  about  the  teeth  have  been  reported  from  the 
injudicious  use  of  the  drug  in  question. 

Topographical  Anatomy  of  the  Pulp  Chambers  and  Canals. 

A  familiarity  with  the  topographical  anatomy  of  pulp  chambers  and 
canals  is  an  essential  preliminary  to  their  proper  opening  and  cleansing. 
Figs.  401,  402,  and  403  (see  pp.  443-445)  illustrate  the  average  pulp- 
chamber  forms. 

The  following  outline  figures  (Figs.  404-439)  are  exact  reproductions 

Fig.  404.  Fig.  405. 


s 


Tpper  central  incisor.  Upper  lateral  incisor. 

of  sections  made  of  typical  teeth  which  have  been  shown  by  comparison 

with  numerous  other  sections  to  be  about  the  average  anatomical  forms. 

The  Ujiper  Central  Incisor. — The  pulp  chamber  (Fig.  404)  approxi- 


FORMS  OF  PULP  CHAMBERS  AND   CANALS 


447 


mates  in  form  that  of  the  tooth  itself.     The  opening  of  the  canal  is 
seen  to  be  almost  circular,  and  in  the  central  axis  of  the  tooth. 

Upper  Lateral  Incifor. — The  chamber  of  the  lateral  incisor  (Fig.  405) 
has  a  similar  form  ;  the  canal  exhibits  a  tendency  to  diverge  from   the 


Fig.  406. 


Fig.  407. 


Fig.  408. 


Upper  lateral  incisors  (Ottolengui). 

straight  line  toward  the  apical  end  (see  Figs.  406-408).     The  entrance 
to  the  canal  is  nearly  oval. 

Upper  Canine. — The  chamber  of  the  upper  canine  is  large  and  open 
and  has  an  elliptical  canal  entrance  (Fig.  409j.     The  root  of  this  tooth 


Fig.  409. 


Fig.  410. 


Fig.  411. 


Upper  canines. 


may  also  deflect  from  the  line  of  the  general  axis.     In  rare  cases  a 
bifurcation  of  the  root  is  seen  (Figs.  410,  411). 


Fig.  414. 


Upper  first  bicuspids. 

The  upper  first  bicuspid  very  commonly  exhibits  a  bifurcation  of 
the  roots  which  may  extend  to  any  distance  toward  the  crown  (Fig.  412). 
At  its  entrance  the  pulp  canal  has  a  dumb-bell  form,  the  handle  of  the 
dumb-bell  being  much  attenuated.  The  distinct  canals  may  begin 
almost  at  the  base  of  the  chamber,  or  be  evident  only  near  the  apices 


448 


THE  TREATMENT  AND  FILLING   OF  ROOT  CANALS. 


of  the  roots.  Two  distinct  canals  may  be  present  even  in  the  absence 
of  l)if iircation  of  the  root.  The  roots  of  this  tooth  may  be  much  curved. 
Fig.  413  presents  a  condition  occasionally  seen  :  a  triiurcation  of  the 
root  of  a  bicuspid.  Fig.  414  represents  a  section  through  the  buccal 
roots;  Fig.  414  also  shows  the  neck  section  of  the  tooth.  In  the  same 
mouth  Mere  found  three  bicuspids  exhibiting  the  same  condition.  The 
bifurcated  cuspid,  Fig.  411,  was  from  the  same  denture. 

Upper  Second  Bicuspid. — Sections  of  two  typical  forms  of  upper 
second  bicuspid  are  shown  in  Fig.  415,  a  and  h.  In  such  a  case  as  b — 
far  from  uncommon — it  will  readily  be  seen  what  dangers  exist  as  to 
the  difficulty  of  perfectly  filling  the  flat  general  canal  beyond  the  ellip- 
tical obstruction.     The  neck  section  in  both  types  is  almost  alike. 

Upper  First  Molar. — The  neck   section  of  the   up})er  first  molar 


Fig.  415. 


Fig.  416. 


Upper  second  bicuspid. 


Upper  first  molar. 


(Fig.  416,  a)  shows  a  free  entrance  to  the  palatal  root;  the  anterior 
buccal  root  has  a  triangular  entrance,  near  the  mesio-buccal  angle  of 
the  tooth.  The  entrance  to  the  disto-buccal  root  is  very  small;  h,  Fig. 
416,  shows  a  section  through  the  buccal  roots  of  the  tooth.  Cases  are 
occasionally  seen  where  a  short  crown  is  associated  with  very  long  and 
divergent  roots  (Fig.  417). 


Fig.  418. 


Fig.  419. 


Upper  molar. 


Upper  second  molars. 


Upper  Second  3IoIar. — The  arrangement  of  canals  in  the*  second 
upper  molar  (Fig.  418,  a)  is  much  like  that  in  the  first;  except  that 
the  tooth  has  a  compressed  form  which  brings  the  canal  entrances  closer 
together.  A  section  through  the  buccal  roots  is  seen  in  Fig.  418,  6. 
This  tooth  occasionally  presents  marked  aberrations  in  the  location  and 


FOBMS  OF  PULP  CHAMBERS  AND   CANALS. 


449 


distribution  of  pulp  canals.  Fig.  419  illustrates  a  case  in  which  there 
was  a  trifurcation  of  the  palatal  root.  Other  abnormalities  of  the  canals 
of  upper  molars  are  shown  in  Figs.  420-425  (Ottolengui  ^). 


Fig.  420. 


Fig.  421. 


Fig.  422. 


Fig.  423. 


Fig.  424. 


Fig.  425. 


Upper  molars  (Ottolengui). 


Zipper  Third  MoJar. — The  three  roots  of  the  upper  third  molar  are 
frequently  compressed  together,  giving  the  external  appearance  of  a 


Fig.  426. 


Q 


Upper  third  molars. 


single  round  conical  root.     In  many  instances  there  will  be  found  but 
a  single  large  canal,  as  in  Fig.  426,  a.     The  rule  is  three  canals,  as 


Fig.  428. 


Fig.  429. 


Lower  incisors  and  canine. 


shown  in  Fig.  426,  b,  which  shows  also  a  section  through  the  buccal 
roots.     The  root  is  generally  curved  backward  more  or  less. 

1  Methods  of  Filling  Teeth. 
29 


450 


THE  TREATMENT  AND  FILLING   OF  ROOT  CANALS. 


Lower  Anterhr  Teeth. — The  forms  of  the  canals  and  canal  entrances 
to  the  lower  anterior  teeth  are  shown  in  Figs.  427-429.  The  form 
of  })artial  canal  bifurcation  shown  in  Figs.  428  and  429  is  noted 
frecjnently  in  longitudinal  secttions  of  typical  teeth. 

Lover  Bicuxjiiih. — The  forms  of  the  canals  in  the  lower  bicuspids 
are  mucli  alike;  the  canal  of  the  first,  however,  exhibits  a  tendency  to 
the  dund)-bell  form  of  entrance  (Figs.  430,  431).     Tortuosities  of  the 


Fig.  430. 


Fig.  431. 


Lower  first  bicuspid. 


Lower  second  bicuspid. 


canal  are  far  from  uncommon,  many  of  them  of  such  nature  as  to  ren- 
der full  and  complete  entrance  to  their  ends  next  to  impossible ;  in 


Fig.  432. 


Fig.  433. 


Fig.  434. 


Lower  bicuspids. 


Fig.  432  the  root  was  of  corkscrew  form,  in  Fig.  433  bent  at  right 
angles,  and  in  Fig.  434  a  short  crown  is  associated  with  an  extremely 
long  and  bent  root. 


Fig.  435. 


Lower  first  molars. 


Lower  First  Molar. — The  lower  first  molar  usually  presents  two 
canals  :  a  large  open  canal  for  the  posterior  root,  as  seen  in  Fig.  435, 
a  and  b,  while  the  anterior  root  presents  a  flat  ribbon-like  canal  very 


F0B3fS  OF  PULP  CHAMBERS  AND  CANALS. 


451 


difficult  of  fiitranee.  A  transverse  longitudinal  section  of  the  ante- 
rior root  is  shown  in  Fig.  435,  c.  In  order  to  effect  an  entrance  to 
the  majority  of  these  canals  it  is  absolutely  essential  that  the  rubber 
dam  be  :)])plied  and  the  tooth  well  dried.  A  section  through  both  roots 
is  shown  in  Fig.  435,  b.  Not  uncommonly  two  distinct  anterior  canals 
are  found,  and  in  rare  instances  two  distal  roots  may  be  present,  as 
shown  in  Fig.  435,  d.  The  roots  of  this  tooth,  as  those  of  the  other 
lower  molars,  as  a  rule,  bend  backward.  Fig.  436  (from  Ottolengui) 
shows  an  exaggeration  of  this  bending. 

This  tooth  not  infrequently  requires  canal  treatment  before  the  roots 
are  fully  formed.     A  section  through  the  anterior  half  of  an  immature 


Fig.  436. 


Fig.  437. 


Lower  finst  molar. 


Lower  lirst  molar,  immature. 


tooth  is  shown  in  Fig.  437,  «;  through  the  posterior  half.  Fig.  437,  6. 

Loiver  /Second  Molar. — A  section  of  the  lower  second  molar  resem- 
bles that  of  the  first,  but  distinct  double  canals  in  the  anterior  root  are 
more  frequently  seen,  as  shown  in  the  section  of  the  anterior  half  in 
Fig.  438,  6. 

Lower  Third  Molar. — In  the  lower  third  molar  the  roots  are  fre- 
quently compressed  together,  exhibiting  bifurcation  toward  their  apices 
(Fig.  439). 


Fig.  438. 


Fig.  439. 


a  0 

Lower  second  molar. 


Lower  third  molar. 


The  canals  of  any  tooth  may  exhibit  constrictions  or  flexions  at  any 
points  of  their  lengths.  Although  there  is  no  absolute  indication  as  to 
the  presence  of  flexions  or  abnormal  lengths,  an  examination  of  the 
overlying  gum  should  always  be  made,  when  lengths  and  irregularities 
may  possibly  be  determined  if  the  gum  tissue  and  alveolar  wall  be  very 


45*2  THE  TREATMENT  AND  FILLING   OF  ROOT  CANALS. 

thin.  If  any  of  those  irreo;ularities  be  present  it  is  important  that  they 
be  discovered  and  additional  care  be  taken  to  eliect  a  complete  entrance 
to  the  canals. 

Instruments  for  Canal  Treatment. 

The  description  thus  far  has  included  the  territory  to  be  operated 
upon  and  its  condition  as  regards  sepsis,  the  agents  commonly  employed 
to  produce  asepsis  and  antisepsis,  and  those  applied  to  maintain  these 
conditions.  The  first,  the  condition  of  the  root  canals  and  dentin  ;  the 
second,  the  various  antiseptics  employed  therein ;  the  third,  the  several 
materials  used  as  canal  fillings.  The  next  study  includes  the  instru- 
ments employed  and  their  specific  applications. 

The  first  are  enamel  chisels.  These  are  employed  to  cut  down  weak 
unsupported  enamel  walls  and  those  portions  of  enamel  removable  by 
such  instruments,  which  interfere  with  direct  access  to  the  pulp  canals. 
The  next,  burs,  of  several  forms ;  the  first,  that  known  as  the  "  dentate 
fissure  bur,"  for  cutting  enamel ;  next  rose,  inverted  cone,  and  oval  forms 
for  enlarging  cavities  and  removing  infected  dentin.  Next,  several 
forms  of  broaches,  canal  cleansei^s,  and  jwohes,  Gates-Glidden  7'eamers 
for  enlarging  canals  ;  syringes,  pluggers,  and  finally  rubber  dam  and  the 
appropriate  selection  of  clamps. 

In  relation  with  this  latter  device,  it  is  to  be  recalled  that  demon- 
strations have  shown  the  saliva  to  be  a  highly  infective  fluid,  for  the 
reason  that  it  contains  a  variety  of  pathogenic  organisms  which  must  be 
excluded  from  pulp  canals  if  asepsis  of  these  passages  is  hoped  for.  No 
other  single  means  serves  so  effectively  as  isolation  by  the  rubber  dam. 

A  variety  of  syringes  will  be  required,  a  large  instrument  for  irriga- 
tion (Fig.  440),  to  wash  away  loose  debris  which  may  be  present  in  the 
cavities ;  smaller  syringes  will  be  required  to  accurately  place  definite 
quantities  of  medicaments  in  canals  (Figs.  441,  442,  and  443). 

Dentate  fissure  burs  are  invaluable  instruments  for  removing  por- 
tions of  sound  enamel  walls  which  interfere  with  direct  access  to  the 
root  canals.  Cutting  from  within  outward,  giving  the  bur  a  sawing 
motion,  a  groove  may  in  a  few  minutes  be  extended  across  the  occlusal 
face  of  a  molar  from  a  distal  cavity  to  a  point  directly  over  the  ante- 
rior root. 

Large  rose,  inverted  cone,  and  oval  burs  are  employed  to  remove 
the  dentin  which  may  obstruct  direct  entrance  to  the  canals ;  these  are 
as  a  rule  to  be  used  with  a  draw-cut,  placed  first  in  the  deepest  portion 
of  the  cavity,  and  while  revolving  drawn  toward  the  operator.  Care  is 
to  be  exercised  that  no  more  than  necessary  of  the  walls,  particularly 
the  floor  of  the  pulp  chamber,  is  to  be  burred  away,  to  avoid  mechan- 
ically weakening  the  tooth. 


INSTRUMENTS  FOB  CANAL   TREATMENT. 


453 


The  broaches  employed  are  of  several  forms.     A  broach  is,  accurately 
speaking,   an  instrument    designed    to    enlarge    openings;    so  that  the 


Fig.  440. 


Fig.  441. 


Fig.  442. 


Dental  syringe. 


Minim  syringe. 


J.  X.  Farrar's  alveolar  abscess  syringe. 


barbed  nerve  broach  is  not  employed  as  a  broach  but  as  a  pulp-extrac- 
tor (Fig.  444).  They  and  other  forms  of  extractors  (Fig.  445)  are  used 
to  loosen  and  remove  debris  from  canals. 


454  THE  TREATMENT  AND  FILLING   OF  ROOT  CANALS. 

Fig.  443. 


Bulb  syringe. 


The  toughness  of  these  instruments  is  remarkable.  They  are  so  tem- 
pered that  they  can  be  bent  in  any  desired  direction  and  when  properly 
manipulated  will  readily  follow  a  small  and  crooked  canal  to  the  apex 
without  danger  of  breaking  off.     Two  forms  :  with  sharp  hooks,  for 


Fig.  444. 


Barbed  puli)-extractors  and  holder. 

removing  the  pulp  ;  and  straight,  with  the  ends  slightly  roughened, 
for  carrying  a  shred  of  cotton  in  cleansing  out  the  canal  or  treat- 
ing; alveolar  abscess. 

The  next  instruments  employed  in  this  connection  are  what  are 
known  as  Donaldson's  pulp-canal  cleansers  (Fig.  446).  The  points  of 
these  pulp-canal  cleansers  are  reduced  so  as  to  enter  the  canal  readily, 
and  the  barbs,  which  are  cut  of  just  sufficient  depth  to  accompli.-^h 
their  work,  are  arranged  spirally  around  the  shaft,  in  effect  forming  a 
screw,  so  that  no  two  cuts  are  exactly  opposite  each  other  (see  enlarged 
view,  a,  Fig.  446).  With  ordinarily  careful  usage  these  cleansers  will 
remove  the  pulp  substance  perfectly,  without  liability  to  be  broken  or 
to  become  fastened  in  the  canal.  If  at  any  time  the  instrument  does 
not  withdraw  readily  from  the  root,  a  turn  or  two  to  the  left  (unscrew- 
ing) will  at  once  release  it. 

Made  of  tough  steel  piano-wire,  with  polished  rubber  handles ;  also 
without  handles,  to  be  used  in  broach-holder. 

The  enlarged  view  of  the  Gates-Glidden  nerve-canal  drill  (Fig. 
447)  shows  the  peculiarity  of  the  safety  Glidden  point,  which  will  not 


INSTRUMENTS  FOB  CANAL  TREATMENT. 
Fig.  445.  Fig.  446. 


455 


Dr.  Donaldson's  spring- 


Dr.  Donaldson's  pulp-canal  cleansers. 

enlarge  the  canal,  but  will  merely  guide 
the  drill  into  a  canal  no  wider  than  itself, 
until  it  reaches  tlie  root-apex,  through 
which  only  the  sharp  point  will  pass,  and 
produce  a  sensation  of  pain  that  gives 
notice  of  its  protrusion  ;  yet,  unless  the 
foramen  is  wider  than  the  base  of  the 
guide,  the  Gates  drill  will  not  cut 
through  the  end  of  the  root — a  danger 
that  the  improved  drill  is  specially 
designed  to  avoid.  The  reamers  are 
made  with  their  thinnest  part  near  the 
junction  of  shaft  and  stem,  so  that 
should   fracture  of  the  tool  occur,  a  long       l: 

tempered  nerve-bristles,    piecc    will    be  left    protruding   from    the 
tooth   and   may  be  readily  withdrawn. 
Using  the  series,  one  after  the  other,  with  care  and  judgment,  even 

a  tortuous  canal  may  be  suitably  enlarged ;  but  it  should  be  kept  in 

mind    that    many    roots    are    thin    at    their 

apical    portions,    and    their    canals,    if   much 

enlarged,    may    be    cut    through     laterally ; 

hence    the    advisability    of    employing    usu- 
ally the  smaller  sizes   of  drills,   and  always 

the  smallest  first  when  the  canal  is   narrow. 
There  is  a  diversity  of  opinion  as  to  the 

wisdom  and  propriety  of  using   reamers   of     improved  oates-Giidden  nerve- 

\  1  canal  drill  for  engine  work. 

any   kind    in   pulp    canals.       They    are    con- 
demned in  toto   by  some  operators ;   others  advise  their   employment 
in  all  cases. 


P'lG.  447. 


456  THE  TREATMENT  AND  FILLING   OF  ROOT  CANALS. 

The  Cleansing  of  Canals. 

The  student  has  been  made  familiar  with  the  pathological  conditions 
he  is  called  upon  to  treat,  and  with  his  armamentarium,  including  the 
medicinal  agents  employed  in  their  correction,  and  is  now  prepared  to 
apply  the  one  to  the  other. 

It  is  most  apropos  at  this  juncture  that  the  arguments  for  and  against 
the  reaming  of  root  canals  should  be  reviewed.  The  valid  objections 
urged  against  reaming  as  a  routine  practice  are,  iirst,  the  danger  of 
encroachment  upon  the  cementum  by  the  reamer ;  second,  the  l)reaking 
of  the  delicate  reamers  in  the  canal  and  the  difficulty  and  often  impos- 
sibility of  removing  the  fragment  when  such  accident  occurs  ;  third,  the 
liability  of  forming  false  canals  by  inability  to  confine  the  drill  to  the 
anatomical  canal.  The  argument  advanced  in  support  of  the  practice  is 
the  direct  and  ready  access  attained  by  it  to  the  length  of  the  canal. 
Owing  to  the  fineness  and  tortuosity  of  many  canals  it  is  impossible  for 
the  operator  to  assure  himself  that  he  has  thoroughly  cleansed  and  filled 
them  ;  by  accurately  and  properly  reaming  the  canals  directly  accessible 
to  fine  reamers  they  are  given  such  form  that  a  filling  may  be  placed 
with  a  reasonable  assurance  that  the  apex  is  hermetically  sealed.  It  is 
urged  that  as  many  roots — notably  the  anterior  roots  of  lower  molars, 
the  anterior  buccal  roots  of  upper  molars,  the  roots  of  upper  bicuspids 
and  of  lower  incisors — have  a  flattened  form,  their  pulp  canals  have  a 
ribbon  form.  In  reaming  such  canals  there  is  danger  of  the  reamer 
impinging  upon  the  cementum  at  the  thin  portion  of  the  root.  The 
advocate  of  root  reaming,  therefore,  advises  in  such  cases  the  employ- 
ment of  Donaldson's  canal  cleansers  to  scrape  away  the  canal  walls, 
enlarging  them  uniformly. 

The  danger  of  breaking  reamers  is  always  an  imminent  one,  al- 
though such  accidents  are  commonly  due  either  to  poorly  made  or 
imperfectly  tempered  instruments,  or  to  carelessness  upon  the  part  of 
the  operator.  Even  the  most  skilful  must  be  ever  on  the  alert  to  detect 
any  unusual  resistance  oifered  to  the  advance  of  the  reamer.  This 
danger  increases  if  the  direction  of  the  canal  diverges  from  a  straight 
line.  It  is  obvious  that  with  any  instrument  which  is  being  rotated,  its 
point  must  be  kept  in  line  with  its  shaft  to  minimize  the  strain  on  the 
part  immediately  above  the  cutting  portion. 

The  employment  of  reamers  is  therefore  advised  only  in  nearly  straight 
and  rounded  roots  ;  the  central  idea  to  keep  in  mind  is  that  reamers  are 
employed  merely  to  uniformly  enlarge  canals  which  already  exist,  never 
to  form  new  ones.  Root  canals  which  have  a  flattened  form  are  en- 
larged by  means  of  the  cleansers,  using  progressively  increasing  sizes, 
and  supplementing  their  action  where  and  when  necessary  with  sulfuric 


THE  CLEANSING   OF  CANALS. 


457 


Fig.  448. 


acid,  as  advised  bv  Dr.  J.  E.  Callahan.^  This  method  is  of  great  value  ; 
it  furnishes  a  means  for  entering  and  thoroughly  cleansing  and  enlarg- 
ing canals  which  before  its  introduction  were  regarded  as  impossible  of 
entry. 

It  has  no  doubt  been  observed  by  every  operator,  how  seldom  roots 
which  have  been  well  prepared  for  artificial  crowns  of  the  post  variety 
become  the  seat  of  pericementitis.  This  fact  sug- 
o-ests  that  the  mechanical  removal  of  the  existing 
boundary  walls  of  the  root  canals,  by  removing 
those  portions  of  dentin  invaded  by  septic  organ- 
isms may  lessen  the  opportunity  of  sepsis.  Miller 
has  shown-  that  this  infection  of  dentin  about 
canals  is,  as  a  rule,  superficial  (Fig.  448).  The 
observations  made  in  the  essay  of  Dr.  Miller 
show  also  that  any  danger  to  the  lateral  peri- 
cementum by  invasion  of  the  dentinal  tubules 
leading  from  the  root  canal  is  remote  in  the 
extreme.  Infection  to  some  depth  does  occur, 
however  (Fig.  449).  It  is  undisputed  that  the 
source  of  septic  infection  of  the  pericementum 
is  from  the  canals  by  way  of  the  apical  foramen. 


II 


Fig.  449. 


■  i:ii  ■if! 


V\ 


Fig.  448.— Sector  of  a  cross  section  from  a  diseased  root:  a,  cement;  h,  stratum  granulosum  : 
.c,  very  narrow  and  finely  branched  tubules  ;  d,  infected  district.  (X  150.) 

Fi".  449.— Dentin  from  the  root  of  an  abscessed  tooth,  showing  the  penetration  of  cocci  to  a 
depth  "of  about  ^^  mm.  (jjs  in.).    The  side  a-b  bordered  upon  the  canal.  (X  1000.) 

1  Proc.  Ohio  State  Denial  Society,  1894.  ^  Dental  Cosmos,  1890,  p.  353. 


458  THE  TREATMENT  AND  FILLING   OF  ROOT  CANALS. 

and  if  the  tract  there  represented  be  made  aseptic  no  trouble  need  be 
feared. 

As  the  object  in  all  succeeding  operations  is  to  remove  and  not  to 
institute  a  septic  condition,  care  must  be  exercised  that  no  septic  organ- 
isms be  introduced  by  the  operator  into  the  field  of  operation.  The 
first  step  is  therefore  the  rendering  aseptic  of  this  field.  The  teeth 
should  be  cleansed  first  with  a  brush  and  soap,  then  the  mouth  be  rinsed 
with  an  antiseptic,  as  3  per  cent,  pyrozone,  10  per  cent,  solution  of 
nieditrina,  or  a  lilac-colored  solution  of  potassium  permanganate.  The 
instruments  are  to  be  sterilized,  and  to  effect  this  object  an  excellent 
means  is  by  dipping  the  mechanically  cleansed  instruments  in  strong 
ammonia  water.^  If  any  food  or  pulp  debris  occupy  the  pulp  chamber  it 
is  to  be  washed  away  with  the  antiseptic  employed  to  sterilize  the  mouth. 
The  rubber  dam  is  adjusted,  and  direct  sterilization  of  the  canals,  and, 
when  indicated,  of  the  tissues  at  the  apex  of  the  root,  is  to  be  attained. 

Method  of  Entrance  to  Canals. — The  first  step  or  stage  of  the 
operation  is  the  gaining  of  direct  and  free  access  to  every  canal  of  the 
tooth.  This  may  at  times  appear  to  involve  the  removal  of  an  undue 
amount  of  the  crown  of  the  tooth.  Unfortunately  this  is  true,  but 
efforts  at  the  conservation  of  too  much  of  the  crown  structures  and 
form  are  frequently  followed  by  incomplete  cleansing  and  filling  of  the 
canals.  This  latter  is  the  greater  evil  of  the  two,  so  the  cutting  away 
of  the  crown  is  always  to  be  done  when  necessary  to  accomplish  the 
end  in  view. 

In  the  vast  majority  of  cases  in  which  it  is  necessary  to  remove  a 
putrescent  or  septic  pulp  the  carious  process  has  invaded  the  crown  of 
the  tooth  extensively  ;  the  cavity  of  decay  is  therefore  excavated  until 
perfectly  free  from  carious  dentin  ;  weak  enamel  walls  are  dressed 
away  by  means  of  enamel  chisels,  and  usually  direct  access  to  the  pulp 
chamber  is  gained.  This  is  still  insufficient ;  the  cavity  must  be 
opened  so  that  the  finest  size  of  canal  bristle  can  be  carried  directly  to 
the  apex  of  the  root  without  danger  of  fracturing  the  instrument. 

In  central  incisors,  as  the  carious  cavities  usually  open  upon  the 
approximal  surfaces,  entrance  is  gained  to  the  pulp  chamber  by  extend- 
ing at  the  palatal  aspect  of  the  cavity  a  groove  from  the  cavity  to 
over  the  entrance  of  the  pulp  chamber  (a,  Fig,  450). 

The  same  rule  is  observed  with  the  lateral  incisors  and  canines. 
Should  the  pulp  have  died  subsequently  to  the  insertion  of  fillings 
which  are  mechanically  faultless,  entrance  to  the  pulp  canal  is  made  in 
the  basilar  pit  (b,  Fig.  451).  For  canines  the  opening  is  made  at  a 
higher  point,  about  one-third  the  way  toward  the  cutting  edge.  These 
openings,  while  they  should  be  large  enough  to  afibrd  free  access  to  the 

'  See  also  Cha[)ter  IV. 


THE  CLEANSING   OF  CANALS. 


459 


canals,  should  not  be  made  so  large  as  to  weaken  the  crown,  or  there  is 
danger  of  fracturing  it  when  in  physiological  use. 

Cavities  in  bicuspids  invading  the  pulp  are  usually  upon  the  ap- 
proximal  surfaces  ;  they  are  to  be  extended  over  the  occlusal  face  of 
the  tooth  until  access  to  the  canals  may  be  had  (see  Fig.  452). 


Fig.  453. 


Fig.  450.      Fig.  451. 


Fig.  452. 


Cavity  in  bicuspid. 


The  same  procedures  are  to  be  followed  in  molar  teeth.  In  lower 
molars  if  the  carious  cavity  be  upon  the  distal  wall,  it  is  to  be  artificially 
lengthened  across  the  occlusal  face  until  the  probe  may  be  carried 
directly  into  each  canal  (Fig.  453,  a) ;  the  same  method  is  pursued  if 
for  a  mesial  cavity.  In  upper  molars,  especial  care  is  required  to  gain 
primary  access  to  the  anterior  buccal  root,  and  tooth  structure  must  be 
cut  away  until  this  access  is  secured  (Fig.  453,  b).  Should  the  carious 
cavities  open  upon  the  buccal  faces  of  the  posterior  or  lingual  faces  of 
the  anterior  teeth,  the  upper  cavity  edge,  that  farthest  from  the  gum, 
must  be  extended  toward  the  cutting  edge  of  the  tooth  until  a  bent 
probe  may  be  readily  passed  to  the  apex  of  each  root  (Fig.  453,  c).  In 
operating  upon  many,  or  most,  of  the  canals  of  the  posterior  teeth  it  is 
necessary  to  bend  the  pulp  extractor  or  canal  cleanser  until  it  is  almost 
or  quite  at  a  right  angle  with  the  instrument  carrier. 

In  the  six  anterior  lower  teeth  where  openings  are  to  be  made  in 
them  in  the  absence  of  large  cavities  of  decay,  entrance  is  effected 
through  the  lingual  wall. 

The  advice  of  Dr.  J.  Foster  Flagg  is  appended,  as  to  the  position 
of  tap  openings  to  be  made  in  the  several  teeth,  when  the  teeth  if 
carious  have  not  the  carious  cavity  in  such  position  as  to  afford  access, 
to  the  pulp  chamber  : 

"  By  means  of  a  diamond  drill  or  an  inverted  cone  bur,  a  rough 
spot  is  made  in  the  centre  of  the  face  to  be  perforated ;  this  prevents 
slipping  of  the  spear-pointed  drill  which  is  then  employed  to  enter  the 
pulp  chamber.  The  outlines  of  the  chamber  are  to  be  obliterated  with 
burs."  The  dentate  bur  is  a  most  effective  means  of  enlarging  such 
openings.     "  The  opening  is  to  be  enlarged  until  a  fine  probe  may  be 


4G0  THE  TREATMENT  AND  FILLING   OF  ROOT  CANALS. 

passed   into  each  canal  ;   the  teeth   are  tapped  in   the   following   sit- 
uations : 

Upper  Teeth. — Centrals  and  laterals  :    On  the  lingual  face. 

Canines  :  On  the  tuberosity,  or  disto-labially. 

First  or  second  bicuspids  :  On  occlusal  or  buccal  face. 

First  molars  :  On  occlusal,  or,  as  a  second  choice,  on  buccal  face. 

Second  molars  :  On  occlusal,  mesio-occlusal,  or  buccal  face. 

Third  molars  :  On  mesio-occlusal  face. 

Loirer  Teeth. — Centrals  and  laterals  :  On  lingual  face  just  posterior 
to  cutting  edge. 

Canines  :  On  disto-labial  portion  near  the  gum. 

Bicuspids  :  On  mosio-buccal  face. 

First,  second,  and  third  molars  :  On  mesial,  buccal,  or  mesio-occlu- 
sal face." 

Treatment  of  Canals. 

The  tooth  and  adjacent  teeth  being  isolated  by  the  rubber  dam, 
direct  access  to  each  canal  having  been  gained,  the  tooth  having  its 
walls  sterilized  and  each  instrument  which  has  been  or  is  to  be  used 
being  sterilized,  the  subsequent  procedures  depend  entirely  upon  the 
condition  of  the  pulp  chamber,  canals,  and  dentin  (and  perhaps  the  peri- 
cementum), as  regards  sepsis.  One  of  the  several  conditions  described 
in  the  opening  of  the  chapter  is  present ;  which  of  these  it  is,  governs 
the  therapeusis. 

First :  A  case  in  which  the  pulp  has  been  intentionally  devitalized  and 
extirpated.  The  pulp  having  been  removed  en  masse  it  has  carried  with 
it,  provided  of  course  no  organisms  have  been  introduced  during  or  subse- 
quent to  its  extirpation,  all  of  the  sources  of  infection.  The  remote 
danger  is  now  the  existence  of  small  fragments  of  pulp  tissue  which 
if  unremoved  might  form  a  soil  for  the  development  of  organisms  ob- 
taining entrance  to  them  ;  or  blood  may  have  escaped  into  the  canals 
where  the  dead  pulp  was  torn  from  its  connection  at  the  apex.  These 
must  both  be  removed. 

Hydrogen  dioxid,  being  the  agent  which  will  most  quickly  and 
effectively  disorganize  the  blood  corpuscles,  is  carried  into  the  canals 
and  permitted  to  act  for  a  few  minutes,  when  it  is  absorbed  by  means  of 
cotton,  or  taper  twists  of  bibulous  paper  ;  then  canal  cleansers,  beginning 
with  the  smaller  sizes,  are  employed  to  scrape  the  walls  of  the  canals  free 
of  anv  adherent  pulp  shreds  or  odontoblasts  which  may  have  been  torn 
oif  when  the  pulp  was  removed.  Larger  sizes  are  to  succeed  these 
until  the  caliber  of  the  canal  is  made  larger  and  smooth.  If  it  be  a 
round  root  and  there  be  any  interference  with  the  passage  of  these 
instruments  to  the  apex  of  the  root,  it  is  evident  that  the  same  difficulty 
would  be  found  in  carrying  filling  material  to  its  apex.     A  judicious 


TREATMENT  OF  CANALS. 


461 


Fig.  454. 


reaming  of  the  root  removes  this  difficuhy  and  is  therefore  done.  That 
size  of  the  Gates-Ghdden  reamer  Avhich  will  enter  the  canal  readily  is 
revolved  by  hand,  or,  if  in  the  engine,  is  revolved  very  slowly,  stopping 
the  moment  any  resistance  is  felt.  The  reamer  is  frequently  withdrawn 
to  remove  the  debris  which  collects  behind  it.  As  soon  as  resistance 
is  felt,  a  fine  canal  cleanser  is  passed  beyond  the  point  and  the  Malls 
scraped,  when  the  reamer  is  reapplied  ;  this  alternation  of  instruments 
is  continued  until  sensitivity  shows  that  the  point  of  the  reamer  has 
reached  the  pericementum.  The  next  size  of  reamer  is  then  employed 
to  enlarge  the  canal  uniformly.  As  soon  as  a  canal  is  reamed  a  tem- 
porary dressing  of  alcohol  on  cotton  is  placed  in  it  to  prevent  the  ingress 
of  debris  from  other  canals — that  is,  if  it  be  a  tooth  having  two  or  more 
roots.  In  upper  molars,  the  palatal,  and  in  lower  molars  the  distal, 
root  is  to  be  first  cleansed  and  dressed.  If  the  subject  of  operation  be 
a  single-rooted  tooth,  preparation  is  now  made  for  hermetically  sealing 
the  apex  and  filling  the  canal ;  if  a  multi-rooted  tooth,  the  canal  next  in 
size  is  entered  if  the  root  be  round  as  evidenced 
by  the  general  shape  of  the  canal.  For  example, 
the  anterior  roots  of  lower  molars,  the  buccal  roots 
of  upper  molars  or  of  bicuspids,  which  exhibit  a 
round  opening,  have  usually  but  not  always  a 
rounded  body  ;  those  showing  a  ribbon-like  out- 
line are  likely  to  have  a  corresponding  outward 
form.  Any  eflPorts  at  reaming  such  canals  should 
be  confined  to  that  portion  showing  a  rounded 
opening ;  thus,  if  a  lower  molar,  the  finest  reamer, 
rotated  by  hand,  the  device  of  Dr.  AV.  AV.  Walker 
(Fig.  454),  is  employed  to  enter  and  enlarge  the 
buccal  and  lingual  extremities  of  the  ribbon-like  canals.  Any  further 
enlarging  should  be  done  with  the  canal  cleansers.  The  same  rule 
applies  to  the  buccal  roots  of  npper  molars  and  to  bicuspids.  When 
any  doubt  exists,  the  enlarging  should  always  be  done  with  the  cleansers 
instead  of  the  reamers. 

Not  infrequently  cases  are  found  in  which  the  root  canals,  or  one 
of  them,  may  have  such  contracted  caliber  as  to  refuse  entrance  to  the 
finest  canal  cleansers.  As  a  rule,  such  canals  will  be  found  in  the  buc- 
cal roots  of  upper  molars  and  the  anterior  root  or  roots  of  lower  molars  ; 
occasionally  the  bicuspids,  particularly  the  upper  first  bicuspids,  will 
exhibit  this  condition.  It  is  in  such  cases  that  the  method  of  cleansing 
and  enlarging  introduced  by  Dr.  Callahan  will  be  found  eifective.  A 
rose  bur  is  employed  to  form  a  small  pit  of  which  the  entrance  of  the 
pulp  canal  is  the  centre.  In  this  pit  a  drop  of  sulfuric  acid,  50  per 
cent,  solution,  is  placed  ;    immediately  npon  the  contact  of  the  acid  the 


Walker  pulp-canal 
reamers. 


462  THE  TREATMENT  AND   FILLING   OF  BOOT  CANALS. 

finest  size  of  Donaldson  canal  cleanser  is  passed  as  far  as  it  will  go  into 
the  canal,  the  cleanser  is  inserted  and  partially  withdrawn,  scraping 
away  the  calcinm  sulfate  formed  by  the  action  of  the  acid  upon  the  cal- 
cium salts  of  the  tooth.  The  acid  is  quickly  neutralized  and  fresh 
applications  are  made  drop  by  drop,  the  scraping  ;ind  pumping  with  the 
cleanser  being  contiuued  until  the  point  of  the  instrument  is  felt  to 
reach  or  pass  the  aj)i('al  foramen.  Any  organic  matter,  such  as  filaments 
or  minute  fragments  of  pulj)  tissue,  which  may  luive  been  present  in  the 
canal  is  destroyed.  This  applies  also  to  organic  matter  undergoing  de- 
composition or  to  organisms  which  may  be  present.  As  there  is  no 
marked  degree  of  force  required  in  the  operation  it  may  be  pursued 
even  in  cases  of  pericementitis  or  acute  abscess,  to  gain  direct  and  free 
entrance  to  the  seat  of  morbid  action,  the  focus  of  germ  development. 

In  the  event  of  the  operator  being  unable  to  detect  through  instru- 
mental means  the  openings  of  minute  canals.  Dr.  Callahan  advises  that 
a  pellet  of  cotton  containing  a  minute  portion  of  acid  be  placed  over  the 
]n-obal)le  situation  of  each  canal  and  sealed  in  over  night.  The  follow- 
ing day,  when  the  rubber  dam  is  applied  and  the  cavity  dried,  the  spot 
of  application  of  acid  will  be  represented  by  a  small  white  area,  in 
wdiich,  if  a  canal  entrance  exist,  it  will  be  represented  by  a  black  dot. 
A  pit  is  made  at  this  point  and  acid  is  applied,  when  entrance  by  cleansers 
is  attempted  ;  should  failure  to  gain  entrance  result,  it  is  most  probable 
that  the  canal  is  almost  or  quite  obliterated  with  secondary  deposits 
formed  by  a  receding  pulp,  hence  no  future  sepsis  is  probable.  As 
soon  as  the  cleanser  is  felt  to  touch  or  pass  the  apical  foramen  the 
canals  are  syringed  out  with  a  saturated  solution  of  sodium  bicarbonate. 
Carbon  dioxid  is  disengaged,  which  drives  the  debris  left  in  the  canals 
into  the  pulp  chamber,  and  the  acid  is  neutralized. 

Thus  far  has  been  described  the  entrance  to  and  thorough  cleansing 
and  uniform  enlarging  of  canals  of  a  tooth  from  which  the  intentionally 
devitalized  pulp  has  been  extracted  ;  the  immediate  question  is,  What 
treatment  shall  now  be  pursued  ?  Owing  to  the  method  of  pulp  with- 
drawal, the  contents  of  the  dentinal  tubules  are  as  yet  chemically  un- 
changed ;  and  it  scarcely  requires  argument  to  demonstrate  that,  can 
they  be  kept  in  a  stable  condition,  they  constitute  the  best  material  for 
occupancy  of  the  tubules.  Examining  the  list  of  medicaments  applica- 
ble as  preservatives  zinc  chlorid  is  the  agent  fixed  upon  as  the  one 
which  will  best  procure  an  unchangeable  condition  of  the  contents  of 
the  tubules.  The  experiments  of  Prof.  Jas.  Truman  ^  have  shown  that 
this  agent  quickly  diffuses  through  a  capillary  tube  containing  albumin, 
converting  it  into  a  whitish  coagulum,  an  albuminate  of  zinc,  which 
every  anatomist  knows  to  be  one  of  the  most  efficient  of  all  preserva- 
^  Proc.  Academy  of  Stomatolor/y,  Philadelphia,  1894. 


THE  EOOT-CAXAL  FILLING.  463 

tives.  Anatomical  specimens  of  parts  injected  with  a  zinc  chloric! 
solution,  and  which  have  been  subjected  to  all  the  conditions  known  to 
favor  the  development  of  putrefaction,  remained  unchanged  after  the 
lapse  of  years.  It  is  advised,  therefore — advice  endorsed  by  a  majority 
percentage  of  operators — that  a  solution  of  zinc  chlorid  be  now  placed 
in  each  canal.  A  twist  of  absorbent  cotton  is  dipped  in  a  solution  of 
the  salt.  Should  the  apical  foramen  be  large,  a  weak  solution,  about 
10  per  cent.,  is  employed  ;  if  fine,  the  strength  of  the  solution  may  be 
40  per  cent.  Unless  carelessly  manipulated  or  too  great  an  excess  of 
the  coagulant  be  employed  there  is  but  little  danger  of  forcing  the  solu- 
tion beyond  the  apex  of  the  root.  After  about  ten  or  fifteen  minutes 
the  application  is  withdrawn  and  cotton  or  paper  cones  passed  in  the 
canal  to  absorb  any  excess  of  the  chlorid  which  may  be  present,  and  the 
canals  are  now  ready  for  filling. 

The  Root-canal  Filling. 

AVhen  oxychlorid  of  zinc  has  been  determined  upon  as  the  perma- 
nent canal  filling,  the  preliminary  treatment  of  the  canal  with  zinc 
chlorid  solution  is  superfluous,  as  the  coagulating  and  antiseptic  action 
of  the  zinc  chlorid  nsed  in  making  the  oxychlorid  cement  fully  answers 
the  purpose  in  the  short  period  of  time  elapsing  before  chemical  com- 
bination of  the  fluid  and  powder  results  in  a  hardened  body. 

Examining  the  available  statistics  regarding  the  several  materials 
which  have  been  employed  for  canal  filling  in  such  cases,  there  is  found 
a  greater  percentage  of  success — that  is,  a  fewer  number  of  cases  pres- 
ent subsequent  evidences  of  sepsis — when  zinc  oxychlorid  has  been  used. 
This  is  quite  in  accord  with  rational  therapeusis  ;  the  material  is  capable 
of  hermetically  sealing  the  apex  and  is  unchangeable  in  the  conditions 
surrounding  it.  Its  antiseptic  action  probably  jjlays  little  or  no  con- 
tinued ]iart,  disappearing  shortly  after  the  material  sets  ;  it  is,  however, 
indisputable  that  when  this  material  has  been  employed  as  a  pulp  caj)- 
ping  it  has  not  infrequently  converted  the  entire  pulp  into  a  hyaline 
coagulum  which  has  remained  permanently  aseptic. 

This  material  is  mentioned  first  on  account  of  the  ease,  readiness,  and 
certainty  with  which  it  may  be  placed. 

Gutta-percha  ranks  second  in  point  of  favor  as  a  canal  filling ;  this 
not  on  account  of  any  deficiency  of  specific  properties  contraindicating 
its  use,  but  there  is  not  the  same  certainty  of  accurate  placement  and 
hermetic  sealing  as  with  the  oxychlorid.  Gold  and  tin,  the  remain- 
ing materials  which  have  found  any  extensive  employment  in  such 
cases,  are  open  to  the  same  common  objection,  viz.  difficulty  of  manipu- 
lation. 


464  THE  TREATMENT  AND  FILLING    OF  ROOT  CANALS. 

These  are  the  practically  irremovable  materials.  The  removable 
materials  whieli   hav(>  been  recommciKled  ar(>,  first — 

Cotton. —  It  is  (hie  to  Proi'.  J.  Foster  Flat^tr  tiiat  this  substam-e  has 
been  extensively  emj)l()ye(l,  not  as  a  filling  material  per  xc,  but  as  a 
medium  holding  an  antiseptic.  The  variety  of  cotton  employed  is  the 
crude  unearded  cotton  wool.  Dr.  Flagg-  cites  as  a  proof  of  the  imper- 
meability of  this  material  when  properly  packed,  that  bales  of  cotton 
which  have  floated  in  sea-water  for  long  periods,  when  opened  show  no 
evidences  of  moisture  in  their   interior. 

Evidence  regarding  the  value  and  danger  of  this  material  is  con- 
flicting. It  is  asserted  by  the  advocates  of  cotton  canal  fillings  that, 
properly  inserted,  they  remain  unchanged  for  long  periods,  are  readily- 
packed  into  position,  and  if  necessity  demand  may  be  readily  removed.. 
Those  who  oppose  the  use  of  cotton  assert  that  it  soon  becomes  filled 
with  products  of  decomposition,  and  that  after  some  years  the  texture 
of  the  material  is  destroyed,  rendering  its  removal  very  difficult.  In 
consequence  of  these  conflicting  opinions,  the  weight  of  evidence  being 
w'ith  those  who  oppose  its  use,  cotton  has  found  but  limited  endorsement. 

The  other  removable  materials,  salol  and  paraffin,  are  innovations 
too  recent  to  determine  their  value  and  position  as  canal  fillings.  The 
reports  regarding  salol  are  sufficiently  conflicting  to  warrant  advising 
its  use  only  in  conjunction  with  a  central  mass  of  gutta-percha  or  tin 
points ;  the  salol  filling  the  space  between  the  gutta-percha  or  metal 
point  and  the  walls  of  the  canal. 

These  ai'e  the  arguments  for  and  against  the  several  materials ;  the 
weight  of  evidence  being  largely  in  favor  of,  first,  the  oxychlorid  of 
zinc ;  and  second,  gutta-percha. 

The  question  is,  now.  When  shall  the  canals  be  filled  ?  Shall  it  be 
done  immediately,  or  shall  a  period  be  permitted  to  elapse  for  assurance 
that  no  inflammatory  action  shall  arise  and  the  filling  be  a  bar  to  its 
prompt  reduction  ?  There  are  two  causes  which  might  be  productive 
of  inflammatory  action  :  First,  the  dental  manipulations  of  removing 
the  pulp  and  cleansing  the  canals  might  be  productive  of  sufficient 
irritation  to  give  rise  to  inflammatory  reaction  ;  in  that  event  the  open 
canal  would  afford  an  escape  for  inflammatory  effusions.  The  second 
danger  would  depend  upon  wdiether  septic  organisms  had  been  intro- 
duced or  had  not  been  thoroughly  destroyed  ;  their  sealing  in  the  canals 
might  be  productive  of  septic  inflammation.  If  the  foregoing  meas- 
ures of  cleansing  have  been  followed  it  is  scarcely  possible  that  any 
organisms  could  survive.  General  experience  demonstrates  that  in  but 
a  small  percentage  of  cases  does  the  pericementum  suffer  markedly  from 
traumatism  during  the  cleansing  and  sterilizing  of  canals,  so  that  the 


THE  BOOT-CANAL  FILLING.  465 

weight  of  evidence  clearly  teaches  that  such  canals  may  be  filled  at 
once,  and  little  or  no  reaction  occur. 

Freshly  mixed  zinc  oxychlorid  being  markedly  irritating  to  vital 
tissues,  it  is  usual  to  place  between  the  paste  and  the  tissues  of  the 
apical  region  a  barrier  to  the  former.  This  may  be  of  gutta-percha.  A 
very  fine  cone  of  gutta-percha  about  one-quarter  inch  long  is  dipped  in 
oil  of  eucalyptus  or  oil  of  cajuput  to  soften  it ;  it  is  then  carried  to  the 
apex  of  the  root  upon  a  fine  probe  and  pressed  into  position.  Or,  a 
small  pellet  of  cotton  is  dipped  in  a  strong  solution  of  thymol  or  aristol. 
It  is  extremely  probable  that  when  the  freshly  mixed  oxychlorid  is 
placed  over  it,  the  cotton  becomes  converted  into  amyloid  which  her- 
metically and  permanently  seals  the  apical  foramen  ;  the  same  change 
occurs  in  the  cotton  upon  which  the  oxychlorid  is  carried  into  position. 
Slender  wisps  of  cotton  are  rolled  thin  enough  to  pass  readily  into  the 
canals.  A  thin  paste  of  oxychlorid  is  mixed,  the  cotton  wisps  are 
rolled  in  it  until  the  meshes  are  full,  when  the  extremity  of  a  wisp  is 
caught  upon  the  end  of  a  long,  smooth,  and  slender  canal  plugger  and 
carried  up  the  canal  to  contact  v/ith  the  guard  at  the  apex  ;  the  plugger 
is  withdrawn  about  one-eighth  of  an  inch,  and  that  length  of  the  cotton 
is  crimped  upon  itself;  the  remainder  of  the  canal  is  plugged  in  the 
same  manner  until  it  is  full,  when  the  surplus  length  of  the  cotton  is 
cut  oif  and  bibulous  paper  is  pressed  against  the  canal  filling  to  absorb 
the  surplus  zinc  chlorid.  The  floor  of  the  pulp  chamber  may  be  covered 
with  the  stiffening  paste  from  the  mixing  slab. 

A  method  by  Avhich  cotton  fiber  loaded  with  the  oxychlorid  may  be 
carried  to  the  root  apex  with  great  accuracy  and  precision  is  as  follows  : 
The  smallest  size  Donaldson  bristle  with  smooth  sides  has  its  hooked 
end  cut  off  with  the  scissors  and  the  cut  end  made  flat  by  rubbing 
lightly  upon  a  fine  Arkansas  stone.  This  may  be  readily  done  by 
grasping  the  bristle  very  near  to  its  point  between  the  thumb  and  index 
finger  and  lightly  rubbing  it  back  and  forth  upon  the  surface  of  the 
stone.  The  bristle  is  then  laid  flat  upon  a  glass  slab  and  burnished 
from  heel  to  point  until  the  surface  is  perfectly  smooth  and  any  burr 
turned  upon  the  point  by  the  action  of  the  burnisher  is  fully  re- 
moved. A  few  fibers  of  cotton  wool  are  then  held  between  the  thumb 
and  index  finger  of  the  left  hand,  the  direction  of  the  fibers  being  in 
the  line  of  the  long  axis  of  the  index  finger.  The  point  of  the  prepared 
broach  is  then  laid  upon  the  cotton  fil)crs,  and  both  broach  and  cotton 
are  rolled  together  between  the  finger  and  thumb.  The  rolling  action 
of  the  finger  and  thumb  serves  to  felt  the  cotton  fiber  on  to  the  broach, 
and  should  be  continued  until  the  cotton  is  evenly  felted  over  the 
squared  end  of  the  broach.  The  whole  operation  is  done  by  the  left 
hand.     The  broach  is  not  twirled  into  the  cotton  with  the  right  hand  as 

30 


466 


THE  TREATMENT  AND  FILLING   OF  ROOT  CANALS. 


Fig.  455. 


is  ordinarily  done  where  a   roughened  eotton-earryino-  ])rol)e   Is  used. 

With  a  smootli  broach  and  the  cotton  fiber  iehcd  on  as  (k'scribed  the 

broach  may  be  pnshed  forward  with  considerable  force  into  a  canal 
Avithout  piuicturing  the  cotton,  which  is  securely  carried  as 
far  as  the  broach  will  go.  On  account  of  the  smoothness 
of  the  sides  of  the  broach  it  may  be  easily  withdrawn  for 
a  slight  distance,  and  then  engaging  in  the  surrounding 
cotton  it  is  used  as  a  pluggcr  to  pack  the  cotton  ahead  of 
it,  and  the  plugging  action  continues  until  the  material  is 
all  ])a('ked  in  })lace.  The  adjustment  of  the  cotton  to  the 
broach  as  described  really  forms  a  tube-like  arrangement 
of  the  cotton  with  the  instrument  in  its  central  lumen — 
an  arrangement  greatly  favoring  the  operation  of  carrying 
the  cotton  into  place  and  enabling  the  operator  to  use  the 
cotton  or  any  suitable  fiber  as  a  vehicle  for  canal  dressings 
or  for  permanent  filling  in  connection  with  the  oxychlorid 
of  zinc  cement. 

If  gutta-percha  be  the  material  selected  for  filling  the 
canal,  a  careful  examination  is  made  to  determine  whether 
the  apical  foramen  be  comparatively  large  or  very  small ; 
in  the  latter  case  chloro-])ercha  may  be  first  pumped  into 
the  canals  ;  in  the  former  it  is  wiser  to  omit  the  fiuid, 
owing  to  the  possibility  of  passing  it  through  the  apical 
foramen.  In  all  cases  where  a  canal  filling  is  to  be  made 
of  gutta-percha  cones  it  is  advisable  to  first  lubricate  the 
walls  of  the  canal  with  one  of  the  antiseptic  oils,  cinnamon, 
eucalyptus,  or  cajuput ;  these  will  facilitate  the  passage  of 
the  point  to  the  apex,  and  as  solvents  of  gutta-percha  will 
soften  its  surface  and  permit  a  more  close  adaptation  to 
the  canal  walls.  Should  the  apical  foramen  be  found  large 
enough  to  admit  the  pointed  extremity  of  one  of  the  gutta- 
])ercha  cones,  the  end  of  the  latter  is  cut  oif.  The  canal  is 
lubricated  with  the  oil,  the  cone  itself  dipped  in  the  same 
medium,  its  base  caught  upon  the  end  of  a  canal  plugger, 
and  it  is  passed  carefully  into  the  canal  as  far  as  it  will  go, 
when  the  plugger  is  withdrawn  ;  blasts  of  hot  air  from  a 
hot-air  syringe  are  directed  against  the  exposed  end  of  the 
cone  until  it  is  softened,  and  it  is  then  pressed  firmly  into 
position  by  means  of  fine  pluggers.  A  sufficient  number 
of  cones  are  added,  softened  and  packed  in  position,  filling 
the  canal  flush  with  the  pulp  chamber. 
In  fine  tortuous  canals  it  is  the  usual  practice  to  first  pumji  them 

full  of  thin  chloro-percha.     A  portion  of  the  solution  is  caught  be- 


J 


Flagg's  dress- 
ing pliers. 


THE  ROOT-CANAL   FILLING. 


467 


tween  the  points  of  a  pair  of  Flagg's  dressing  pliers  (Fig.  455)  and  car- 
ried to  the  opening  of  the  canal,  when,  if  the  points  are  opened,  the 
drop  of  flnid  is  deposited  there ;  it  is  then  piunped  into  the  canal  by 
means  of  a  tine  smooth  broach.  To  minimize  the  leakage  due  to  the 
skrinkage  of  the  chloro-})ercha  in  hardening,  it  is  advised  to  thrust  into 
the  fluid  material  in  the  canal  as  large  a  gutta-percha  cone  as  the  canal 
M'ill  admit.  Dr.  Ottolengui  advises  that  the  pieces  of  silk  described  in 
the  beginning  of  the  chapter  be  used  and  an  end  left  projecting  into 
the  pnlp  chamber,  when,  should  removal  of  the  filling  ever  become 
necessary,  this  end  may  be  caught  and  the  entire  filling  withdrawn. 

Should  it  be  designed  to  fill  the  canal  with  gold,  its  exact  length  is 
measured  by  placing  a  small  disk  of  rubber  dam  over  a  canal  plugger, 
which  may  be  carried  to  the  apex,  and  inserting  the  plugger  in  the 
canal.  The  floor  of  the  pulp  chamber  engages  the  rubber  dam,  and 
when  the  })lugger  point  has  reached  the  end  of  the  canal  the  little  gauge 
])iece  of  rubber  dam  marks  its  exact  length.  Minute  pieces  of  soft  gold 
foil  are  cut,  and  one  by  one  are  carried  to  the  end  of  the  canal,  the  rubber 
upon  the  plugger  being  the  guide  to  completeness  of  access  to  the  root 
apex.  This  method  is  to-day  rarely  followed.  Dr.  W.  S.  How  advises 
the  use  of  shredded  tin  for  sealing  the  apex  of  canals.  By  a  series  of 
fine  probes  the  canal  length  is  measured  (as  shown  in  Figs.  456-460), 


Fig.  456. 


Fig.  i57. 


Fig.  458. 


and  particles  of  shredded  tin  foil  are  carried  to  the  apex  and  impacted 
by  means  of  measured  probes. 

Salol  and  paraffin  are  both  manipulattnl  after  one  manner.  A  very 
fine  probe  is  pas.>ied  into  the  canal  to  its  apex  ;  a  portion  of  the  ma- 
terial is  caught  between  the  beaks  of  a  pair  of  dressing  pliers  (Fig.  455) 
and  held  above  an  alcohol  flame  until  it  is  melted,  when  the  closed 
beaks  are  placed  in  the  canal  beside  the  probe,  and  opened,  and  the  fluid 


468 


Tin:  TREATMENT  AND  FILLING   OF  ROOT  CANALS. 


material  runs  into  the  canal.  Slowly  witlidi'awinu-  the  prohc,  the  fluid 
runs  into  the  .space  oe('U])ie(l  hv  the  j)rol)e,  tilling-  the  canal  to  the  ajx'x  ; 
it  is  advisable,  however,  to  warm  a  broach,  aud  by  a  i)innping  motion 


Fig.  459. 


Fig.  460. 


insure  the  carrying  of  the  filling  to  all  parts  of  the  canal.  If  salol  be 
employed  a  cone  of  gntta-])ercha  of  such  size  as  may  be  readily  carried 
to  the  apex  should  be  thrust  into  the  fluid  material,  virtually  filling  the 
greater  portion  of  the  canal  with  gutta-percha.  Several  trustworthy 
observers  have  noted  a  disappearance  of  salol  from  canals  in  which  it 
has  been  placed  ;  the  gutta-percha  minimizes  the  risk  attendant  upon 
such  disajipearance.  The  gutta-percha  subserves  another  purpose : 
should  it  ever  be  necessary  to  remove  the  canal  filling,  blasts  of  warm 
air  directed  against  the  end  of  the  gutta-percha  may  be  made  to  melt 
the  salol  al)out  it,  wdien  the  cone  may  be  readily  withdrawn.  This 
melting  and  withdrawal  are  more  quickly  accomplished  if  the  central 
mass  be  of  metal. 

Paraffin  is  unchangeable  in  the  conditions  under  Avhich  it  is  placed. 

Treatment  of  Root  Canals  with  Mummified  Pulps. 

The  remaining  member  of  the  aseptic  cases  is  that  of  mummified 
pulp.  So  long  as  these  cases  remain  perfectly  aseptic  they  give  rise  to 
no  symptoms  and  are,  as  a  rule,  uncovered  by  accident,  rarely  by  design. 

Their  usual  history  is  as  follows  :  At  some  time  (perhaps  years) 
before,  an  exposed  or  almost  exposed  pnlp  has  been  covered  with  a  cap 
or  cavity  lining  of  the  oxychlorid  of  zinc.  They  have  remained  com- 
fortable thereafter.  At  some  subsequent  time  it  may  be  necessary  to 
open  the  tooth,  usually  on  account  of  recurring  caries :  the  total 
absence  of  dentinal  sensitivity  is  noted,  the  tooth  has  changed  color  but 


SEPTIC  CASES.  469 

little,  if  at  all,  and  the  operator  burs  carefully  toward  the  pulp  to 
determine  its  condition.  (It  should  be  remarked  here  that  absence 
of  dentinal  sensitivity  in  a  tooth  having  normal  color  and  which  con- 
tains a  very  large  tilling  is  an  indication  of  aseptic  death  of  the  pulp, 
and  the  operator  should  renew  all  of  his  antiseptic  precautions  as  to 
isolation  of  the  tooth  by  the  rubber  dam  and  complete  sterilization  of 
all  instruments  and  of  the  territory  of  operation.)  The  burring  is  con- 
tinued without  any  evidence  of  sensitivity,  and  the  instrument  is  finally 
felt  to  pass  into  the  pulj)  chamber.  There  is  no  odor,  no  escape  of 
fluid,  the  pulp  being  found  dry  and  shrivelled.  If  sterilized  pulp 
extractors  are  passed  into  the  canals,  the  remnants  of  the  pulp  may  be 
withdrawn,  exhibiting  none  of  the  usual  signs  of  decomposition  such  as 
odor  and  confluent  softening. 

It  is  highly  improbable  that  any  organisms  are  present,  unless  they 
should  have  been  introduced  by  the  operator  from  the  exterior.  The 
possibility  of  this  occurring  should  prompt  caution,  for  it  is  the  expe- 
rience of  many  that  although  organisms  have  not  been  present  in  the 
canals,  when  introduced  from  without  they  find  a  fruitful  soil  for  devel- 
opment. Reaction  indicating  infection  may  occur  within  a  few  hours  or 
may  be  delayed  for  perhaps  two  days.  This  condition  may  arise  even 
in  connection  with  teeth  whose  pulps  have  died  under  a  capping  of 
zinc  oxychlorid,  from  the  fact  that  the  quantity  of  zinc  chlorid  used  in 
the  capping  material  was  insufficient  to  completely  saturate  the  pulp 
tissue  and  render  it  permanently  antiseptic.  It  is  advisable,  therefore, 
to  cleanse  the  canals  with  some  powerful  and  penetrating  antiseptic  to 
destroy  any  chance  organisms  and  to  insert  a  probationary  though  per- 
fect root  filling  until  the  time  of  danger  has  passed.  The  antiseptic 
which  meets  the  indications  is  the  ethereal  25  per  cent,  solution  of 
hydrogen  dioxid  known  as  pyrozone,  ])ermitted  to  remain  in  the  canals 
for  several  minutes.  The  canals  are  then  dried,  and  R)r  the  temporary 
filling  salol  is  the  rational  indication.  At  the  expiration  of  three  days 
if  no  evidences  of  pericementitis  are  present  the  operator  may  renK)ve 
the  salol,  reapply  the  antiseptic,  and  fill  the  canals  with  oxychlorid  or 
with  gutta-percha. 

The  use  of  formalin  (40  per  cent,  aqueous  solution  of  formic  alde- 
hyde) should  be  mentioned  in  this  connection.  A  5  per  cent,  solution 
placed  in  the  canals  is  a  coagulant  antiseptic  which  quickly  and  cer- 
tainly penetrates  into  and  sterilizes  the  finest  recesses. 

Septic  Cases. 

The  second  great  class  of  cases,  the  septic,  comprises  those  in 
which  the  pulp  has  undergone  some  extent  of  decomposition.  As  a 
rule,  the  first  organisms  which  invade  pulp  tissue  are  the  staphylo- 


470  THE  TREATMENT  AND  FILLING    OF  BOOT  CANALS. 

cocci  and  streptococci,  which  find  a  suitabk'  liabitat  in  tlic  live  ])nlp. 
Advancino-  first  ah)n(i:;  the  lines  of  the  veins,  their  toxic  waste  jn'od- 
nets  cansinii"  intlainniation,  the  organisms  invade,  peptonize,  and  li(jnefy 
the  iiitlanuuatory  effusions.  As  these  cocci  advance  toward  the  apex 
of  the  root,  the  necrotic  and  altered  tissues  which  arc  left  behind 
become  the  breeding-ground  of  other  organisms,  ])artienlarly  the  bacteria 
of  putrefaction.  The  altered  portions  of  pulp  tissue  are  decomposed 
into  products  of  progressively  simpler  chemical  comj)osition,  until  all 
of  the  albuminous  substances  have  been  transformed  :  first  peptones  are 
formed,  further  decomposition  produces  ptomains,  next  such  bases  as 
leucin,  tyrosin,  and  the  amines,  together  with  fatty  acids  ; '  finally  the 
end  ])roduets  are  hydrogen  sulfid,  ammonia,  carbon  dioxid,  and  water 
(see  Fig.  31)<S).  "Fcrmentcdion  and  jyutref action  can  only  occur  where  the 
fungi  concerned  lire,  and  the  extent  of  decomposition  is  conditioned  by  the 
iiuniher  of  fungi"  (Ziegler). 

As  there  are  several  distinct  types  of  decomposition,  so  is  there  a  cor- 
responding numl)er  of  varieties  of  organisms.  The  septic  cases  may  be 
divided  into  two  classes  :  First :  Those  in  which  septic  invasion  has  not 
passed  beyond  the  apical  foramen  and  given  evidence  of  pericemental 
irritation  or  inflammation,  these  tissues  being  threatened  though  not 
invaded.  Second  :  Those  in  which  the  pericementum  has  become  the 
seat  of  septic  invasion.  This  latter  class  is  subdivided  according  to  the 
nature  and  extent  of  the  septic  processes  :  the  first  subdivision  comprises 
cases  of  acute  pericementitis  non-purulent ;  the  second,  of  chronic  peri- 
cementitis without  evident  pus  formation  ;  the  third,  of  purulent  peri- 
cementitis, which  may  be  either  acute  or  chronic, 

1.  In  the  first  of  the  first  class  of  these  cases — those  in  which  the 
suppurative  process  has  invaded  the  pulp  to  near  its  end — the  necrotic 
portions  of  the  pulp  are  undergoing  putrefactive  decom]>osition.  To- 
ward the  end  of  the  process,  when  the  apical  portion  of  the  pulp  is 
invaded,  it  is  not  uncommon  to  find  evidences  of  ])ericeniental  irritation ; 
this  frequently  ceases  spontaneously,  as  though  the  irritation  had  caused 
the  formation  of  a  barrier  between  the  tissues  of  the  apical  region 
and  the  suppurating  pulp.  An  increasing  discoloration  of  the  dentin 
shows  the  contents  of  the  dentinal  tubules  to  be  also  undergoing  de- 
composition. It  is  necessary  to  remove  this  mass,  destroying  the 
products,  the  causes,  and  the  soil  of  decomposition  :  this  without  carry- 
ing infection  to  the  vital  tissues  beyond  the  apex.  When  the  odor  of 
hydrogen  sulfid  may  be  detected,  it  is  evidence  that  the  ultimate  de- 
composition of  albuminous  matter  is  in  progress.  As  it  is  quite  ])rol)- 
able  and  an  imminent  danger  that  organisms  might,  n])on  a  l)roach 
injudiciously  employed,  be  carried  from  the  body  of  the  putrescent 
1  Ziegler,  Oeneral  Paiholucjij,  1895,  p.  437. 


SEPTIC  CASES.  471 

mass  to  the  apex  of  the  root,  it  is  the  part  of  wisdom  and  prudence  to 
destroy  the  organisms  as  a  primary  measure.  There  is  no  quicker  or 
effective  means  of  destroying  H^S,  and  probably  the  causes  leading  to 
its  production,  than  applications  of  iodin.  The  reaction  involved  in 
the  decomposition  of  H2S  by  iodin  Mas  pointed  out  by  Dr.  AV.  F. 
Litch  :'  "  In  passing  a  stream  of  hydrogen  sulfid  through  tincture  of 
iodin,  the  latter  element  seizes  upon  the  hydrogen,  forming  hydriodic 
acid,  which  remains  in  solution,  the  sulfur  falls  as  a  precipitate  ;  the 
solution  is  decolorized,"  Any  excess  of  iodin  which  remains  may  be 
readily  removed  by  an  ap])Hcation  of  ammonia  water,  a  solution  of 
ammoniimi  iodid  being  formed  which  may  be  readily  washed  away. 

A  penetrating  antiseptic  is  now  indicated,  to  sterilize  to  as  great  a 
depth  as  practicable.  A  10  per  cent,  solution  of  formalin  fultils  this 
indication.  It  is  permitted  to  act  for  some  time.  The  contents  of  the 
canal  are  scraped  away,  never  pushing  the  broach  by  which  the  scraping 
is  done,  for  fear  of  carrying  organisms  deeper  into  the  canal.  As  the 
end  of  the  canal  is  approached  5  per  cent,  formalin  is  substituted. 

As  stated,  septic  canals  contain  certain  fatty  bodies  and  derivatives 
of  albumin,  together  with  more  or  less  partially  disorganized  pulp  tissue 
and  a  mixed  bacterial  infection.  Examining  the  list  of  therapeutic 
agents  it  is  seen  that  one  of  them,  sodium  dioxid,  possesses  properties 
capable  of  neutralizing  each  of  the  offending  elements.  This  material 
may  be  employed  either  in  the  solid  form  or  in  solution.  Solutions  of 
sodium  dioxid  must  be  made  with  great  care  to  prevent  escape  of  the 
oxygen.  A  tumbler  of  distilled  water  is  set  in  a  vessel  containing  ice- 
water;  into  the  distilled  water  the  sodium  dioxid  is  dusted  very  slowly 
in  small  amounts.  Each  addition  is  attended  by  the  evolution  of  heat." 
The  sodium  dioxid  is  added  to  the  point  of  saturation,  and  reduced  to 
the  desired  percentage  strength  by  additions  of  distilled  water .^ 

A  drop  of  the  saturated  solution  is  placed  upon  a  Avisp  of  asbestos 
fiber  (as  it  destroys  cotton  fiber)  and  is  carried  into  the  canal ;  in  a  few 
moments  the  cavity  may  be  syringed,  and  a  deeper  application  of  the 
dioxid  solution  made — this  time  of  50  per  cent,  solution.  Each  time 
the  asbestos  is  removed  it  is  seen  that  the  discolored  dentin  surroundino- 
the  canal  becomes  whiter;  the  discoloring  matter  in  the  tubules  has  been 
destroyed. 

When  a  broach  may  be  passed  freely  to  the  apex  of  the  root,  and 
the  solution  comes  away  clear  from  the  root,  sterilization  is  presumably 

1  Dental  Co!<moi<,  1882. 

^  Dr.  Wm.  Trueman  advises  tliat  the  soldered  lid  of  the  can  containing  the  oxid  be 
perforated  as  a  pepper  caster,  and  tlie  sodium  dioxid  shaken  into  the  distilled  water 
through  the  perforations. 

'  E.  C.  Kirk,  Denial  Cosmos,  vol.  xxxv.  p.  195;  F.  T.  Van  AVoert,  ibid.,  vol.  .\.\xvi. 
p.  499. 


472  THE  TREATMENT  AND   FILLING    OF  ROOT  CANALS. 

complete.  A  10  per  cent,  solution  ol"  snlf'ni'ic  acid  is  piiinjx'd  into  the 
canals  by  means  of  iridium  l)roaelie.s  ;  this  neutralizes  any  free  alkali 
Avhich  may  be  present.  The  canal  or  canals  are  next  washed  out  with 
hot  distilled  water,  dried  with  cotton,  filled  with  alcohol,  and  well  dried 
by  blasts  of  warm  air. 

Many  operators  immediately  and  permanently  fill  such  canals ; 
however,  as  there  is  the  possibility  that  sterilization  may  not  be  abso- 
lute, it  is  the  usual  })ractice  to  fill  the  canals  tentatively  yet  perfectly. 
Salol  and  a  metallic  point  make  an  excellent  canal  fillin<>;  in  such 
cases.  When  the  canals  and  dentinal  walls  are  dried  by  nutans  of  the 
alcohol  and  warm  blast  they  are  filled  with  salol  made  very  fluid,  and 
the  metallic  point  thrust  into  the  canal  containing  it.  Some  slight 
pericemental  disturbance  may  follow,  but  quickly  subsides  under  the 
influence  of  a  counter-irritant  applied  to  the  gum  over  the  root  (tr. 
iodin.,  tr.  aconit.  et  chloroform,  ad.  pars  wq.  The  crown  cavity  is  sealed 
with  sticky  temporary  stopping  for  a  few  days,  when  if  the  condition 
of  the  pericementum  is  found  normal,  the  salol  filling  is  removed  (if 
the  operator  desires)  by  heating  a  pair  of  tweezers  and  grasping  the 
protruding  end  of  the  metal  cone.  It  is  the  general  practice  to  then 
fill  the  canal  with  oxychlorid  or  gutta-percha. 

Should  the  case  present  evidences  of  profound  change  in  the  contents 
of  the  tubules,  i.  e.  much  discoloration,  the  50  per  cent,  solution  of 
sodium  dioxid  may  be  sealed  in  the  canal  for  a  day ;  the  next  day  the 
canals  are  syringed  freely  with  an  acid  solution  of  hydrogen  dioxid. 
Dr.  Kirk  advises  that  the  dentin  be  saturated  with  the  sodium  dioxid 
solution,  then  upon  the  addition  of  hydrochloric  acid,  hydrogen  dioxid 
is  formed  wherever  the  sodium  has  penetrated,  and  drives  out  the  soapy 
matters  formed  by  the  action  of  sodium  hydroxid  upon  the  products  of 
decomposition. 

Preliminary  to  filling  the  canals  it  is  the  usual  practice  to  fill  them 
for  a  few  minutes  with  an  antiseptic,  which  will  exercise  an  influence 
over  a  considerable  period  of  time.  Of  all  antiseptics,  oil  of  cinnamon 
gives  evidence  of  the  most  prolonged  presence  when  so  placed. 

Cases  in  which  Pericementitis  is  Present. 

The  next  class  for  consideration  includes  the  cases  in  which  the 
tissues  of  the  apical  region  are  invaded.  The  first  evidence  of  such 
invasion  is  tenderness  of  the  tooth  upon  pressure.  The  cause  of  this  is, 
no  doubt,  the  inflammatory  reaction  of  these  tissues  consequent  upon  con- 
tact and  absorption  of  the  waste  products  of  organisms  which  are 
developing  in  the  pulp  canal.  In  the  milder  cases  the  tooth  is  sore  to 
the  touch,  is  slightly  loose  and  extruded,  and  the  gum  over  the  affected 
root  is  redder  than  normal.     Here,  as  in  all  grades  of  this  disturbance, 


CASES  IN   WHICH  PERICEMENTITIS  IS  PRESEXT.  473 

the  aim  is  to  get  rid,  first,  of  the  causes  of  the  iuflammation  ;  second^ 
when  necessary  to  treat  the  inflammation  itself.  In  entering  the  canals 
of  such  teeth — and  of  course  they  should  be  opened  and  cleansed  as 
quickly  and  as  thoroughly  as  possible — "  The  tooth  should  receive 
lateral  support  against  the  pressure  of  the  burs  used  in  excavating ;  if 
the  cavity  be  approximal  the  tip  of  a  finger  is  placed  against  the  face 
of  the  tooth  on  the  opposite  side  to  the  bur.  Should  the  direction 
of  entrance  be  in  a  perpendicular  line  a  ligature  of  linen  twine  having 
long  ends  may  be  tied  tightly  about  the  neck  of  the  tooth,  and  traction 
exerted  as  a  counter-pressure."  ' 

If  the  conditions  i)erniit,  the  cleansing  and  sterilizing  are  to  be  well 
done  at  once.  Should  the  tooth  be  too  tender  to  permit  the  usual 
manipulations,  the  gross  mass  is  removed  by  treatment  with  sodium 
dioxid  solution  or  by  syringing  with  meditrina  and  stirring  with 
broaches  ;  then  a  pellet  of  cotton  saturated  with  lysol,  a  strongly  alka- 
line and  penetrating  cresol,  is  placed  against  the  putrescent  mass  ;  the 
gum  is  painted  with  iodin  at  a  little  distance  from  the  site  of  the  inflam- 
mation. When  quiet  is  secured,  the  cleansing  and  sterilization  of  the 
canals  should  be  thoroughly  done  ;  and  a  dressing  of  a  sedative  anti- 
septic introduced.  Campho-pheuique  or  cinnamon  oil  answers  well  in 
this  particular. 

In  more  pronounced  cases  the  tenderness,  extrusion,  and  looseness 
of  the  tooth  are  more  marked ;  in  case  the  tooth  should  contain  a  filling 
beneath  which  a  pulp  has  died — and  this  is  a  common  history  of  such 
cases — the  release  of  the  imprisoned  mephitic  gases  is  imperative.  Ex- 
ercising counter-pressure,  a  very  sharp  and  small  spear-pointed  drill  is 
passed  into  the  pulp  chamber ;  it  may  be  necessary  in  cases  of  extreme 
soreness  to  effect  this  entrance  at  the  neck  of  the  tooth  as  the  shortest 
path.  After  a  few  minutes  the  opening  is  syringed  out  with  meditrina, 
and  a  blister  is  applied  over  the  gum  at  a  distance  from  the  tooth,  about 
two  teeth  posterior  to  it.  The  patient  is  directed  to  immediately  take 
a  hot  mustard  foot-bath,  and  to  use  frequently  a  3  per  cent,  solution  of 
pyrozone  or  other  strong  antiseptic  solution  as  a  mouth-Avash.  When 
the  tooth  is  much  extruded  and  is  kept  irritated  by  striking  upon  the 
occluding  tooth,  it  is  advisable  to  place  a  cap  over  the  tooth  jiosterior 
to  the  one  affected.  A  cap  may  be  readily  made  in  a  few  minutes,  by 
taking  an  impression  in  moldine  or  in  plaster  of  the  tooth  to  be  capped, 
pouring  a  small  die  of  fusible  metal ;  drive  this  into  a  block  of  soft 
lead,  and  then  swage  a  piece  of  silver  or  German  silver.  No.  26,  to  fit 
the  die.  This  cap,  covering  the  occlusal  face  and  about  half  the  walls 
of  the  tooth,  is  attached  by  means  of  zinc  phosphate,  thus  securing 
surgical  rest  for  the  affected  tooth.  It  Avas  at  one  time  a  general  prac- 
'  J.  Foster  Flagg's  Lectures. 


474  THE  TREATMENT  AND  FILLING    OF  ROOT  CANALS. 

tice  to  pennit  the  vent  \uAv  drilled  ;it  the  lu'ck  of  a  tooth  to  remain 
open  for  the  escape  of  the  gases  of  decomposition,  consequently  tlie 
cases  were  in  a  constant  state  of  sepsis.  The  practice  is  ol)solete  and 
is  to  be  unqualifiedly  condemned. 

In  cases  where  the  inflammatory  action  runs  liiuh,  the  tooth  is  ex- 
tremely tender,  much  extruded,  and  loose,  the  gum  over  the  tooth  be- 
comes livid,  the  pulse  increases,  there  is  some,  and  it  may  be  marked, 
febrile  action,  the  tongue  is  coated  and  the  breath  oifensive.  Energetic 
measures  are  necessary  to  avert  necrotic  action  in  the  apical  tissues. 
In  this,  as  indeed  in  all  cases  without  exception,  the  promptness  and 
thoroughness  of  relief  depends  primarily  upon  the  thoroughness  with 
which  the  exciting  cause  of  the  inflammation  is  removed,  i.  e.  the  septic 
contents  of  the  pulp  chamber.  In  any  case  where  direct  access  may  be 
had  to  the  canals,  and  this  is  very  frequently  the  case,  every  eifort  short 
of  that  producing  great  suffering  to  the  patient  should  be  employed  to 
wash  away  and  broach  away  the  putrescent  material,  using,  where  ne- 
cessary, sulfuric  acid  to  enter  the  canals,  powerful  antiseptics  always 
preceding  the  broach.  Lysol  is  an  excellent  medicament  in  this  con- 
nection, and  campho-phenique  another.  The  canal  is  syringed  freely 
and  repeatedly  with  3  per  cent,  pyrozone,  which  should  also  be  used  as 
an  antiseptic  mouth-wash.  Local  bloodletting,  as  advised  by  Dr.  G.  V. 
Black,'  is  frequently  an  effective  means  for  securing  relief.  Make  a 
deep  cut  in  the  gum,  clear  to  the  process,  the  incision  to  be  about  one- 
quarter  inch  from  the  margin  of  the  gum  and  encircling  the  neck  of  the 
tooth  ;  this  will  tend  toward  unloading  the  engorged  vessels  of  the  apical 
region.  Dry  cups  over  the  face  and  to  the  neck,  and  always  hot  mus- 
tard foot-baths,  are  valuable  adjuncts. 

Should  the  inflammatory  disturbance  run  high,  and  a  full,  bounding 
pulse,  coated  tongue,  marked  fever,  constipation,  headache,  and  other 
febrile  symptoms  appear,  attempts  should  still  ])e  made  to  abort  the 
inflammatory  action.  After  as  thorough  a  cleansing  of  canals  and  anti- 
septic washing  as  possible  under  the  circumstances,  local  bloodletting 
as  described  and  advised  by  Dr.  Litch '"  is  efficient,  by  means  of  Swedish 
leeches,  washing  the  gum,  touching  it  with  sugar,  then  applying  the 
leech,  which  should  ])e  first  j^laced  in  a  test-tube,  the  mouth  of  the  tube 
then  being  placed  over  the  gum  ;  when  the  leech  is  gorged,  it  drops  back 
into  the  tube.  The  mouth  is  then  rinsed  with  warm  water,  to  continue 
the  bleeding.  Quinin  in  doses  never  less  than  gr.  vj  is  given  in  the  hope 
of  limiting  the  exudation  into  the  inflamed  area.  As  one  of  the  best  and 
most  effective  means  of  derivation  is  the  induction  of  watery  alvine  dis- 
charges, the  patient  may  be  directed  to  take  a  saline  cathartic  or  a  rectal 

^  American  System  of  Dentistry,  vol.  i.  p.  927. 
2  Ibid.,  vol.  i.  p.  928. 


CASES  IN   WHICH  PERICEMENTITIS  IS  PRESENT.  475 

injection  of  half  an  ounce  of  pure  glycerin.  If  the  pulse  remain  full  and 
bounding,  and  headache  persist,  tr.  aconiti  or  tr.  veratri  viridis  is  to 
be  used  as  an  arterial  sedative,  gtt.  j  of  the  tr.  aconiti  rad.,  or  gtt.  ij  of 
the  tr.  veratri  viridis,  repeated  every  hour,  until  the  pulse  slows  and 
lessens  in  volume  and  tension.  At  bedtime,  if  the  inflammation  be  not 
markedly  lessened,  a  sedative  diaphoretic  is  administered,  Dover's  pow- 
<ler  in  full  dose,  gr.  x,  given  in  hot  lemonade  ;  while  the  patient  is  drink- 
ing the  latter  he  or  she  is  to  be  well  wrapped  in  hot  blankets  and  tiie 
feet  and  leos  immersed  in  a  hot  mustard  foot-bath.  Tlie  followino- 
morning  a  saline  cathartic — magnesise  sulph.  5ss — is  given  in  a  goblet 
of  water.  These  directions  (substantially  those  given  by  Dr.  Litch, 
ibid.),  may  be  followed  with  gratifying  results  in  many  cases  ;  even 
when  the  inflammation  is  not  aborted,  its  violence  is  almost  invariably 
lessened. 

Should  the  inflammation  remain  at  its  height  for  more  than  twenty- 
four  hours,  it  is  almost  certain  that  pus  has  formed,  and  the  indication 
is  to  give  it  exit.  A  spear-pointed  bistoury  is  thrust  through  the  gum 
over  the  apex  of  the  aifected  root  with  such  decided  force  as  to  pene- 
trate the  process  if  possible.  In  the  event  of  not  accomplishing  this 
«nd,  the  point  of  a  spear-head  drill  revolving  very  rapidly  is  passed 
through  the  process  to  the  apical  region.  Although  this  operation  may 
be  performed  very  quickly  it  may  be  necessary  to  administer  nitrous 
oxid  to  quiet  the  patient  and  render  the  drilling  painless.  Anesthesia 
may  be  secured  by  means  of  the  injection  of  a  drop  of  a  15  per  cent, 
solution  of  cocain.  Dr.  Black  has  described  a  painless  method  of  effect- 
ing an  entrance  to  the  apical  region.^  A  napkin  is  placed  about  the 
parts,  the  gum  dried  and  touched  at  the  point  of  election  with  a  drop  of 
95  per  cent,  solution  of  carbolic  acid  (trichloracetic  acid  full  strength 
may  be  used).  The  necrosed  membrane  is  scraped  away  by  means  of  a 
€oarsely  serrated  plugger  until  sensation  is  felt,  when  another  dn^p  of 
ticid  is  applied,  and  the  scratching  is  resumed  until  the  bone  is  laid 
bare  ;  a  sharp  chisel  is  then  used  to  open  the  apical  region.  Xo  blood 
should  be  drawn  during  the  o})eration  except  at  the  last  step. 

The  case  in  its  present  stage  belongs  to  and  is  described  in  the  suc- 
<^eeding  cha])ter,  upon  Alveolar  Abscess.  In  any  case  presenting  in 
which  there  is  reason  to  believe  the  patient  is  the  victim  of  syphilis — 
and  alveolar  periostitis  is  an  occasional  accompaniment  of  tertiary  syphi- 
lis ^ — the  use  of  large  doses  of  potassium  iodid  is  imperatively  indicated. 
Unless  decided  measures  are  taken  to  abort  such  cases — and  the  usual 
antiphlogistic  measures  are  of  little  avail — dangerous  involvement  of 
the  general  periosteum  may  occur,  leading  to  necrosis.     Not  less  than 

'  American  Sytitem  of  Dentistry,  vol.  i.  p.  928. 

^  See  case — Heath,  Injuries  and  Duieanes  of  the  Jaws,  3d  edition. 


476  THE  TREATMENT  AND  FILLING   OF  ROOT  CANALS. 

gr.  vj  doses  of  potassium  iodid  are  to  he  adniiuistercd  every  three  hours. 
Should  there  be  eviileuce  of  detachment  of  the  periosteum,  evidenced  by 
boggy  swelling,  a  bistoury  is  to  be  passed  boldly  to  the  bone,  making  a 
laro-c  and  free  incision. 

Treatment  of  Chronic  Pericementitis. 

The  most  usual  form  of  chronic  apical  pericementitis  is  that  associ- 
ated with  pus  formation.  It  will  be  discussed  in  the  succeeding  chapter 
under  the  head  of  Chronic  Apical  Abscess. 

A  not  inconsiderable  number  of  cases  may  be  seen  in  which  pus 
formation  is  not  evident  and  yet  a  chronic  inflammation  is  present  in 
the  tissues  of  the  apical  region.  If  the  pulp  chamber  be  open  the 
cause  is  evident,  and  its  treatment  has  been  described.  A  not  inconsid- 
erable number  of  cases  are  due  to  mal-occlusion.  This  point  is  to  be 
carefully  observed,  for  it  frequently  affects  teeth  containing  vital  pulps 
and  free  from  caries.  The  tooth  is  slightly  loose  and  sore  to  pressure^ 
Examination  reveals  aljnormal  occlusion,  either  too  severe  or  in  the 
wrong  direction.  Should  the  tooth  contain  a  tilling,  it  usually  gives  a 
normal  response  to  applications  of  heat  and  cold  ;  examining  the  filling 
a  spot  is  seen  marking  excessive  occlusion  ;  in  both  cases  grinding  off 
the  redundant  tooth  structure  or  filling  and  applying  a  counter-irritant 
over  the  apex  subdues  the  inflammation.  Its  exciting  cause  being 
removed,  it  subsides. 

A  class  of  cases  is  occasionally  met  with  in  which  there  is  evidence 
of  sluggish  and  persistent  inflammation  al)out  the  apices  of  pulpless- 
teeth  which  have  been  filled ;  acute  inflammatory  disturbance  of  a 
severe  grade  occurs  but  seldom.  The  most  common  cause  of  this  con- 
tinued inflammation  is  probably  the  decomposition  of  a  minute  filament 
of  pulp  tissue  which  has  not  been  removed  from  a  canal  ;  or,  again,, 
well-cleansed  canals  which  have  not  been  filled  to  the  apex.  Such 
cases  are  those  of  mild  sepsis :  perfect  restoration  to  health  is  only  pos- 
sible by  re-cleansing,  sterilizing  and  perfectly  filling  the  canals.  These 
teeth  are  always  more  or  less  hypersensitive  even  though  it  be  unnoticed, 
and  therefore  are  not  of  a  full  measure  of  service  until  cured. 

Other  cases  in  which  there  is  reasonable  assurance  of  perfect  steril- 
ization and  complete  filling  exhibit  vascular  sluggishness  over  the  apex 
of  the  root.  Continued  and  repeated  massage  is  beneficial,^  the  disorder 
being  apparently  due  to  paralysis  of  vessel  walls  and  not  to  septic 
causes.  The  tonus  of  the  vessels  may  be  improved  by  application  of 
the  galvanic  current.  This  principle  has  wide  application  in  general 
medicine  and  surgery. 

It  is  to  be  remembered  that  when  the  tissues  about  the  apex  of  a 

^  Dr.  W.  F.  Relifuss,  International  Dental  Journal,  vol.  xi.  p.  581. 


TREATMENT  OF  CHRONIC  PERICEMENTITIS.  477 

root  have  beeu  irritated,  it  may  be  for  months,  by  the  products  of  a 
decomposing  pulp,  a  series  of  degenerative  changes  may  have  occurred 
in  them  Avhich  require  some  time  to  remedy.  Sterilization  should  be 
prolonged,  and  too  hasty  a  stopping  of  the  canal  be  avoided.  In  such 
cases,  after  each  periodical  treatment  the  canal  should  be  dressed  with 
:Some  stimulant  antiseptic  :  campho-phenique  ;  oil  of  cinnamon,  or  the 
.admirable  1,  2,  3  mixture  of  Dr.  Black  : 

Oil  of  cinnamon,  1  part ; 

Carbolic  acid,  2  parts  ; 

Oil  of  wintergreen,  3      " 

Repeated  applications  of  tr.  aconit.  et  iodin.  are  to  be  made  to 
the  gums. 

A  source  of  chronic  ai)ical  i)ericementitis — frequently  not  detected 
until  abscess  has  formed  and  discharged,  it  may  be,  at  a  distant  point — 
is  found  in  the  death  of  a  pulp  from  thrombus  or  jugulation.  At  some 
period  the  tooth  has  received  a  blow,  or,  it  may  be,  has  been  moved 
too  rapidly  by  a  regulating  a])pliance,  or  idiopathic  pulpitis  has  occurred. 
Years  afterward,  a  chance  examination  may  reveal  a  deeper  color  of 
the  gum  overlying  the  tooth  than  over  the  others;  by  reflected  light  it 
i^hows  an  opacity  or  discoloration  of  the  l)ody  of  the  tooth.  It  may  be 
slightly  sore  to  percussion,  which  elicits  a  dull  sound.  ''Dead  })ulp"  is 
diagnosticated ;  the  tooth  is  opened  under  extraordinary  antiseptic  pre- 
cautions and  cleansed  freely  with  sodium  dioxid — the  ideal  material  in 
this  instance — dried,  and  filled  at  least  tentatively  with  salol. 

Another  class  of  cases  in  which  a  similar  condition  of  the  pulp  is 
found  consists  of  those  in  which  a  pulp  has  died  from  repeated  thermal 
shock  received  through  a  metallic  filling  placed  in  too  close  proximity 
to  it.  Although  constructive  action  resulting  in  secondary  deposits  is 
the  usual  consequence  of  such  irritation,  j^rofound  degenerative  changes 
in  the  tissue  of  the  pulp  frequently  occur  at  later  periods.  The  treat- 
ment is  the  same  as  in  the  preceding  case. 

Unless  the  degree  of  antisepsis  stated  be  em])loyed  in  cleansing  the 
canals  of  such  cases,  an  annoying  and  it  may  be  an  obstinate  perice- 
mentitis is  lighted  up  which  is  difficult  to  conquer. 

A  word  of  caution  should  be  spoken  in  regard  to  the  importance  of 
the  removal  of  inflammatory  troubles,  particularly  the  subacute  forms, 
which  aifect  the  apical  pericementum.  It  is  supposed  and  with  good 
reason  that  not  only  may  tumor  formations  have  their  beginning  in 
chronic  inflammations  ;  various  reflex  disturbances  of  sensation  and  of 
special  sense  may  be  traced  to  such  sources  ;  but  any  inflammation 
having  such  an  anatomical  situation  is  a  smouldering  fire  which  may 
under  certain  systemic  conditions  become  a  pathological  conflagration. 


CHAPTER    XYIII. 

DENTO-ALVEOLAR  ABSCESS. 

By  Hexey  H.  Burchard,  M.  I).,  D.  D.  S. 


Definition. — In  describing  the  septic  inflammation  affecting  the 
tissues  of  the  apical  region  in  the  previous  chapter,  it  was  stated  that  a 
common  result  of  the  inflammatory  action  was  cellular  necrosis  and  pus 
formation  ;  this  condition  is  known  as  alveolar  abscess  or  dento-aheolar 
abscess. 

Although  alveolar  abscess  affecting  some  other  portion  of  the  peri- 
cementum may  and  does  occur  without  death  of  the  pulp/  septic  infec- 
tion and  bacterial  invasion  of  the  tissues  of  the  periapical  region  from 
infected  pulp  canals  is  the  most  common  source  and  cause  of  the  affec- 
tion. The  term  as  technically  applied  refers  to  septic  apical  pericemen- 
titis. 

Causes  of  Dento-alveolar  Abscess. 

The  exciting-  causes  of  the  disease  process  will  be  found  in  the  pyo- 
genic cocci  and  probably  other  pyogenic  organisms  which  inhabit  and 
develop  in  the  deepest  portions  of  the  putrescent  pulp,  finding  entrance 
to  the  periapical  tissues  through  the  apical  foramen  of  the  tooth.  Dr. 
Schreier  of  Vienna  found  diplococcus  jineumonije  to  be  the  excitant  of 
inflammation  in  seventeen  out  of  twenty  cases  of  dental  periostitis 
examined  by  him.'  The  ptomains  and  other  waste  products  formed  as 
the  result  of  the  life  processes  of  these  organisms  cause  poisoning  and 
debility  of  the  cellular  elements  of  the  part.  Even  granting  that  the 
organisms  are  present  as  the  exciting  cause,  there  is  another  factor 
involved  which  determines  to  a  great  extent  the  occurrence,  time  of 
occurrence,  and  severity  of  the  disease,  i.  e.  the  predisposing  causes — 
including  under  this  head  the  condition  of  the  tissues  which  favors  or 
deters  the  development  of  the  organisms. 

Predisposing  Causes. — It  is  unquestionably  true  that  different  in- 
dividuals will  exhibit  in  their  tissues  marked  differences  in  the  degree 

'  Cases  reported  in  Proc.  Academy  of  Stomatology  of  Philadelphia,  1895. 
^  0 ester r.-ungavische  Viertelj.  fUr  Zahnheilh.,  April  1893. 

479 


480  DENTO-ALVEOLAR  ABSCESS. 

of"  resistance  to  the  invasion  of  (lis(>aso  causes.  It  is  a  Avell-recognized 
axiom  of  })athology  that  one  of  the  most  ])otent  antiseptics,  if  not  tlie 
most  j)otent,  is  the  inherent  resistance  of  healtliy  protophism  ;  that  is, 
healthy  tissues  offer  a  barrier  to  the  development  of  the  exciting  causes 
of  disease,  while  tissues  which  are  debilitated  through  any  of  the  many 
causes  that  affect  them  exhibit  a  diminished  resistance  to  the  invasion 
of  the  causes  of  acute  disease. 

Prominent  among  the  causes  which  favor  the  development  and  ex- 
tension of  pyogenic  processes  are  the  inherited  conditions  indefinitely 
classified  as  strumous.  The  tissues  of  children  having  a  family  history 
of,  for  example,  syphilis  or  tuberculosis,  frequently  exhibit  evidences 
of  lack  of  vital  resistance.  They  are  attacked  and  readily  succumb  to 
tigencies  which  affect  children  of  healthy  parentage  but  slightly  if  at  all. 
Inflammations  about  the  teeth  or  of  the  soft  tissues  of  the  mouth  run  a 
severe  course ;  septic  affections  of  the  pericementum  are  attended  by 
involvement  of  neighboring  lymphatics  and  by  evidences  of  septic 
intoxication.  These  predispositions  may  persist  throughout  the  life  of 
the  individual ;  as  a  rule,  however,  they  grow  less  pronounced  or  less 
evident  with  age. 

Acquired  cachectic  conditions  of  the  adult  also  form  a  strong  pre- 
disposition to  invasion  of  the  tissues  by  pathogenic  organisms.  It  is  a 
matter  of  frequent  observation  that  tuberculosis  and,  in  a  more  pro- 
nounced degree,  syphilis  are  constitutional  conditions  which  markedly 
diminish  the  resistance  of  the  tissues.  Inflammatory  disturbances 
which  in  an  individual  free  from  cachexia  would  probably  be  circum- 
scribed, when  they  occur  in  the  cachectic  are  diffuse  and  virulent. 
Local  predisposing  causes  consist  of  faulty  hygiene,  producing  debility 
of  the  tissues,  for  it  is  noted  that  abscess  is  more  likely  to  run  a  virulent 
course  in  unclean  mouths  than  in  those  kept  free  from  fermenting  and 
putrefying  masses  ;  this  is  a  general,  though  not  a  universal  truth. 

Pathology  and  Morbid  Anatomy. 

The  pathology  of  septic  pericementitis  has  been  described  in  Chapter 
XVII.  That  of  alveolar  abscess  begins  as  soon  as  there  is  death  of 
cellular  elements  in  the  exudation.  The  exudation  is  liquefied  in  the 
focus  of  the  inflammation  by  the  action  of  ferments  ;  the  leucocytes  are 
invaded  by  and  strive  to  devour  the  pyogenic  cocci  which  are  present — 
the  species  of  warfare  described  by  Metchnikoff;  the  leucocytes 
succumb,  die,  and  form  pus  corpuscles,  which  are  found  to  contain  the 
pyogenic  cocci.  The  cellular  exudate  is  then  broken  down  into  a 
granular  detritus,  which,  with  the  dead  corpuscles  and  peptonized  effu- 
sion, constitutes  pus. 

The   diplococcus  of  pneumonia   is   said  to   be  a   constant  attendant 


PATHOLOGY  AND  MORBID  ANATOMY.  481 

on  alveolar  abscess,  and  this  particular  organism  is  believed  by 
Schreier  to  be  the  usual  excitant  of  the  inflammatory  action  in  these 
cases. 

The  primary  seat  of  the  abscess  is  usually  hi  the  pericementum, 
between  its  attachment  to  the  cementum  and  its  attachment  to  the 
alveolus.  From  the  central  cavity  of  softening  the  necrotic  process 
spreads  peripherally ;  cell  by  cell  the  inflanunatory  wall  forming  the 
outlines  of  the  abscess  and  the  exudates  are  liquefied  and  the  cavity 
grows  larger.  The  cancellated  bone  about  the  apex  of  the  root  is  in- 
volved and  becomes  the  seat  of  osteomyelitis  and  molecular  necrosis. 
Larger  and  larger  grows  the  volume  of  the  abscess  until  the  periosteum 
covering  the  alveolar  process  is  involved,  softened,  and  raised  from  the 
bone.  The  inflammatory  action  precedes  the  advance  of  the  pus  along 
the  line  of  least  resistance ;  and  if  it  run  high  the  periosteum  may  be 
softened  over  quite  an  extensive  area  and  raised  from  the  bone  by  the 
exudation  beneath  it.  The  pus  penetrating  the  periosteum,  the  soft  tis- 
sues are  involved  and  softened,  when  the  pus  breaks  through  the  mu- 
cous membrane,  discharging  usually  by  the  shortest  route  from  the 
abscess  to  the  exterior.  The  progress  of  septic  destruction  is  along  the 
line  of  least  resistance,  and  although  as  a  rule  this  points  upon  the  ex- 
ternal surface  of  the  gum  immediately  above  the  apex  of  the  affected 
root,  it  may  follow  other  directions.  In  some  cases  the  pus  finds  exit 
through  the  pulp  canal  of  the  affected  tooth,  forming  what  is  commonly 
though  incorrectly  known  as  blind  abscess.  This  form  of  abscess  dif- 
fers from  that  with  external  fistula  as  a  result  of  its  mode  of  formation 
rather  than  because  of  any  essential  difference  in  its  pathology.  The 
history  of  an  acute  inflammatory  stage  is  usually  absent  or  it  has  caused 
but  slight  disturbance.  Invasion  of  the  apical  pericementum  by  bac- 
teria has  been  slow  and  superficial  and  the  inflammatory  reaction 
restricted  to  the  tissue  immediately  surrounding  the  apical  foramen ; 
the  necrotic  process  has  been  ulcerative  in  character,  molecular  death 
of  the  membrane  taking  place  slowly  until  the  tissue  about  the  foramen 
is  lost  and  the  denuded  apex  projects  into  a  necrotic  cavity  which  allows 
of  drainage  of  its  contents  through  the  foramen  and  root  canal.  In 
these  cases  the  abscess  cavity  is  usually  comparatively  small,  and  the 
inflammatory  action  is  less  severe  than  when  the  pus  has  a  longer  path 
of  exit  (see  Fig.  461), 

The  pus  may  exhibit  evidences  of  semi-encystment.  Collections 
may  apparently  remain  in  the  tissues  of  the  gum  for  long  periods  with- 
out fistula.  A  case  in  practice  presented  conditions  similar  to  that 
exhibited  in  the  illustration  (Fig.  462) ;  it  had  existed  for  several  years 
about  a  replanted  tooth,  and  responded  promptly  to  treatment. 

In  other  cases  the  line  of  tissue  destruction  and  pus  escape  is  along 

31 


482 


JJEMV-A L  VEOLA  R  A BSCESS. 


the  pericementum,  tlie  pus  discharging  at  the  neck  of  the  affected  tooth. 

Many  of  these   cases  occur 

in  connection   Avith  pulpless 

teeth  which  have  eh)ugated, 

or  those  in  Avhieli  there  has 

already   been    h)ss    of    i)eri- 

cementum. 

Abscesses  upon  the  upper 
central  or  lateral  incisors  may 

Fig.  461. 


Blind  ubsct'ss  al  the  root  of  an  upper  Acute  alveolar  abscess  of  a  lower  incisor  with  pus  cav- 
Incisor  (Black) :  a,  abscess  cavity  ity  between  the  bone  and  the  periosteum  (Black) : 
in  bone;  b,  drill  hole  exposing  the  a,  pus  cavity  in  the  bone  ;  h,  pus  between  the  peri- 
pulp  chamber  for  treatment.  osteum  and  bone;  c,  lip:  d,  tootli ;  e,  tongue. 

perforate  the  na.sal  floor  (see  Fig.  463).     After  a  period  of  marked  perice- 

FiG.  464. 


Alveolar  abscess  at  the  root  of 
a  superior  incisor  discharging 
into  the  nose  (Black) ;  a,  large 
abscess  cavity  in  the  bone ;  b, 
mouth  (if  fistula  on  the  floor  of 
nostril ;  c,  lip  ;  d,  tooth. 


Alveolar  abscess  at  the  root  of  an  upper 
molar  discharging  into  the  antrum  of 
Highmore  (Black  j:  a,  abscess  cavity  in 
the  bone;  b,  mouth  of  fistula  on  the 
floor  of  the  antrum ;  c,  pus  in  the  antral 
cavity. 


mental  disturbance,  the  inflammatory  action  running  high,  causing  pain 
and  swelling  of  the  nostril  of  the  same  side,  the  symj^toms  may  suddenly 


PATHOLOGY  AND  MORBID  ANATOMY. 


483 


abate  without  any  evident  signs  of  pus  having  been  discharged.  Soon 
after  a  purulent  discharge  may  be  noted  from  the  nostril,  leading  to  the 
belief  that  purulent  nasal  catarrh  (ozena)  is  present ;  many  of  these  cases 
are  diagnosed  and  treated  as  ozena.  In  injection  of  the  pulploss  incisor, 
particularly  ^vith  ])yrozone,  the  pus  and  fluid  are  seen  to  emerge  from  the 
nostril,  exhibiting  the  true  source  of  the  pus.  Abscesses  upon  upper 
second  bicuspids  and  molars  may  perforate  the  iloor  of  the  antrum 
(Fig.  464V 

In  the  lower  jaw  the  pus  may  pass  out  of  the  alveolar  process  and 

Fig.  465.  Fig.  4G6. 


Chronic  alveolar  abscess  at  the  root  of  a  lower  incisor 
with  a  fistula  discharging  on  the  face  under  the 
chin  (Black) :  a,  abscess  cavity  in  the  bone;  b,  b,  b, 
fistula  following  in  the  periosteum  down  to  the 
lower  margin  of  the  body  of  the  bone  and  dis- 
charging on  the  skin. 


Chronic  alveolar  abscess  of  the  root  of 
a  lower  incisor  with  abscess  cavity 
passing  through  the  body  of  the  bone 
and  discharging  on  the  skinbeseath 
the  chin  (Black) :  a,  very  large  ab- 
scess cavity  ;  b,  mouth  of  the  fistula. 


fail  to  perforate  the  overlying  soft  tissues,  pursuing  a  path  ^^  hich  may 
lead  to  its  exit  upon  the  face  beneath  the  jaw  or  chin  (Fig.  465).  In 
others  the  pus  may  burrow  through  the  body  of  the  bone  and  open 
upon  the  face.     (See  Figs.  466,  467.) 

In  a  case  of  persistent  fistula  opening  upon  the  side  of  the  face  over 
the  body  of  the  lower  maxilla,  there  was  no  evidence  of  inflamniatory 
disturbance  in  the  edentulous  gum.  An  exploratory  incision,  made  at 
a  point  indicated  by  a  probe  passed  into  the  sinus,  revealed  the  presence 
of  a  small  root-fragment.  Healing  of  the  fistula  was  spontaneous  upon 
its  removal.  Prof.  M.  H.  Cryer^  records  a  case  of  abscess  opening 
-  Proc.  Academy  of  Stomatology,  1896. 


484 


DENTO-AL  VEOLA  R  A  BSCESS. 


over  the  hody  of  tlio  lower  maxilla  immediately  anterior  to  the  groove 
for  the  facial  artery  (Fig.  4G8).     A  flexible  })robe  passed  into  the  fistula 


Fig.  46"; 


Fig.  468. 


Fistula  passing  down  tlirough  the  body  of  the 
lower  maxilla  (Black). 


Abscess  with  tortuous  sinus  opcninK  up.m 
the  face:  A,  tissue  of  chock;  B,  floor 
of  mouth  ;  C,  abscess  tract. 


a})j)eared  to  enter  the  submaxillary  triangle ;  in  the  absence  of  evident 
dental  cause,  the  case  had  been  diagnosticated  and  treated  as  abscess  of 
the  submaxillary  gland.  The  direction  taken  l)y  the  probe  gave  no 
indication  of  a  tooth  being  involved.  The  usual  thera])eutic  measures 
applied  to  a  submaxillary  abscess  proving  unavailing,  a  serial  examina- 
tion, one  of  many,  of  the  teeth  of  that  side  was  made.  In  one  tooth,  the 
second  molar,  was  a  large  amalgam  filling.  The  pulp  responded,  though 
feebly,  to  the  usual  tests  for  vitality ;  upon  entrance  to  the  tooth  the 
anterior  portion  of  the  pulp  was  found  partially  vital,  the  posterior 
portion  dead  and  decomposing.  The  pulp  was  removed  ;  antiseptics 
were  pumped  through  the  posterior  root,  found  exit  at  the  fistula,  and 
the  causal  relation  of  the  putrescent  pulp  and  the  abscess  was  shown 
by  a  prompt  disappearance  of  the  disease. 

In  one  case  of  abscess  upon  a  lower  third  molar,  the  pus  made  en- 
trance into  the  tissues  about  the  insertion  of  the  internal  pterygoid 
muscle.  Cases  have  been  recorded  in  which  the  pus  from  abscess  about 
a  lower  molar  has  burrowed  through  the  bone  and,  caught  beneath  the 
platysma  myoides  muscle,  it  has  passed  down  the  muscle,  discharging 
from  an  opening  upon  the  neck  or  upon  the  shoulder. 

Abscess  upon  an  upper  molar  may  find  exit  upon  the  face  beneath  the 
malar  bone.  Occasionally  the  duct  of  Steno  may  be  involved  in  the 
abscess  tract  and  salivary  fistula  result.  Dr.  Black  states'  that  the 
cases  of  abscess  opening  beneath  the  malar  bone  are  usually  of  the  acute 
variety.  As  a  rule,  however,  cases  which  exhibit  the  pus  exit  at  a  dis- 
tance from  the  seat  of  abscess  are  of  the  chronic  variety. 

The  acute  and  chronic  cases  differ  as  to  their  clinical  histories. 

1  American  Sydem  of  Dentistry,  vol.  i.  p.  940. 


CLINICAL  HISTORY  OF  ACUTE  ALVEOLAR  ABSCESS.         485 

Clinical  History  of  Acute  Alveolar  Abscess. 

Cases  of  apical  pericementitis  in  which  suppuration  occurs  usually 
present  pronounced  evidences  of  severe  inflaniniatory  action.  The 
throbbing  and  tenderness,  swellino-  and  vascular  engorgement  are 
marked  ;  there  may  be,  and  usually  is,  more  or  less  febrile  disturb- 
ance with  its  attendant  symptoms  ;  a  full,  bounding  pulse,  more  or  less 
oedema  of  the  surrounding  parts,  the  eye  of  the  affected  side  may  be 
injected,  etc.,  as  described  in  Chapter  XVII.  uuder  the  head  of  Acute 
Pericementitis.  In  from  twenty-four  to  forty-eight  hours  a  spot  of 
fluctuation  makes  its  appearance  at  the  summit  of  the  swelling,  the  spot 
becomes  yellow  and  soon  opens,  affording  escape  to  the  abscess  contents. 
As  soon  as  the  pus  has  discharged  the  inflammatory  symptoms  subside 
promptly  and  a  persistent  fistula  remains,  communicating  with  the 
abscess  cavity.  This  comparatively  benign  course  and  termination  is 
not  universal.  It  is  not  at  all  uncommon  to  find  cases  which  at  the 
height  of  the  inflammatory  disturbance  exhibit  evidences  of  septic 
intoxication.  The  septic  substances  formed  by  the  micro-organisms, 
and  in  other  cases  the  organisms  themselves,  gain  entrance  to  the  lymph 
channels  and  are  conveyed  to  the  nearest  lymphatic  glands,  producing 
evidences  of  inflammation  in  them  ;  swelling  and  pain  of  these  glands 
are  very  common.  Cases  are  recorded  in  which  streptococci  appear  to 
have  invaded  the  subcutaneous  tissue,  giving  rise  to  marked  phleg- 
monous inflammation.  Dental  literature  contains  the  records  of  many 
cases  indicating  the  occurrence  of  a  pyemic  condition  consequent  upon 
alveolar  abscess  ;  organisms,  by  gaining  entrance  to  the  blood  channels, 
forming  septic  emboli. 

The  mild  and  less  severe  cases  run  the  average  course  described. 
Many  of  them  l)y  finding  early  exit  of  the  pus  through  the  pulp  canal 
of  the  affected  root  have  comparatively  light  inflammatory  disturbance  ; 
in  those  cases  in  which  the  evacuation  of  the  pus  is  delayed,  or  in 
whicli  the  opening  occurs  at  points  distant  from  the  disease  focus,  the 
inflammatory  action  may  be  severe  and  prolonged.  If  the  pus  point 
toward  the  face,  the  skin,  the  subcutaneous  tissues,  and  it  may  be  the  in- 
ternal periosteum  also  exhibit  evidences  of  marked  inflammation  ;  there 
is  much  swelling,  the  skin  may  become  cedematous,  there  is  redness, 
heat,  and  throbbing  pain.  The  external  application  of  poultices  by  the 
patient,  not  at  all  an  uncommon  mode  of  domestic  treatment,  may 
aggravate  the  symptoms,  soften  the  tissues,  and  induce  the  progress  of 
the  pus  to  the  exterior. 

If  in  any  of  the  cases  which  point  in  the  moutli  an  undue  swelling  is 
formed  at  the  height  of  ])roloiiged  inflammatory  action,  pus  beneath  the 
periosteum   is  to  be  feared,  the  pus  stripping  the  softened  membrane 


486 


DENTO  A  L  VEOLA  R  ABSCESS. 


from  the  bone  over  a  certain  area.  Shonld  these  cases  not  obtain  (|nick 
relief  by  evacnation  of  the  pns,  necrosis  of  the  dennded  bone  may  occur 
(Fig.  409).  lieattachment  of  the  periosteum  may  take  place  even  after 
extensive  separation,  provided  the  pus  be  evacuated  early. 


Fig.  469. 


Necrosis  of  the  buccal  plate  of  the  alveolar  process  from  alveolar  abscess  (Black). 

Cachectic  conditions  exert  a  strong  modifying  influence  upon  the 
course  and  termination  of  alveolar  abscess.  In  strumous  or  debilitated 
persons  the  disease  tends  to  invade  neighboring  structures,  whose  resist- 
ance is  lessened.  This  is  well  illustrated  by  a  case  of  obstinate  maxil- 
lary caries  which  destroyed  the  entire  process  of  one  side,  the  begin- 
ning of  the  disease  being  apical  pericementitis  of  a  lower  bicuspid. 
The  carious  process  became  chronic  soon  after  the  extraction  of  the 
offending  tooth,  and  persisted  until  the  death  of  the  patient  from 
tuberculosis. 

Alveolar  abscess  occurring  in  syphilitic  patients  is  prone  to  involve 
the  deep  structures,  and  more  or  less  necrosis  is  not  an  uncommon 
sequel. 

Clinical  History  of  Chronic  Alveolar  Abscess. 

After  the  subsidence  of  the  symptoms  attendant  upon  the  formation 
and  discharge  of  acute  abscess,  there  is  rarely  a  spontaneous  healing  or 
filling  of  the  abscess  cavity  and  tract  with  healthy  granulation  tissue  ; 
the  development  of  organisms  in  the  abscess  cavity  and  pulp  canal  con- 
tinues and  produces  a  continuance  of  the  suppurative  process,  forming  a 
chronic  abscess. 

In  other  cases  abscess  may  have  developed  without  marked  inflam- 
matory symptoms,  and  yet  a  prolonged  and  obstinate  pus  formation 
occurs  in  the  tissues  of  the  apical  region,  the  pus  finding  exit  through 
the  pulp  canal,  constituting  what  is  known  as  blind  abscess,  one  of  the 
most  common  of  the  chronic  types. 

Many  of  the  cases  which  open  upon  the  face  are  of  the  chronic 
variety ;    during  the  development  of  the  abscess  and  its  discharge  there 


DIAGNOSIS  ASD  PROGNOSIS.  487 

may  be  but  little  evidence  of  inflammatory  action  about  the  affected 
tooth.  This  is  a  common  history  of  cases  which  have  followed  the 
death  of  a  pulp  through  trauma,  years  before  the  discovery  of  the  ab- 
scess. At  some  period  a  tooth  receives  a  severe  blow,  and  for  some 
time  is  the  seat  of  traumatic  pericementitis,  which  subsides  :  it  may  be 
years  after  that  a  fistula  is  established  in  the  mouth  or  upon  the  face, 
without  a  history  of  inflammatory  disturbance. 

As  pointed  out  by  Dr.  Black,  the  direction  of  pus-burrowing  in 
chronic  abscess  is  determined  by  gravity  ;  thus,  if  the  abscess  be  upon 
a  lower  incisor  the  pus  may  burrow,  opening  beneath  the  chin,  as  shown 
in  Figs.  467,  468. 

Sir  John  Tomes '  has  called  attention  to  the  tendency  of  pus  to  open 
at  the  angle  of  the  jaw  in  abscesses  affecting  the  lower  third  molars  (see 
cases  noted  above). 

Diagnosis  and  Prognosis. 

Diag-nosis. — If  the  pericementum  of  a  pulpless  and  open  tooth  have 
been  the  seat  of  acute  and  marked  apical  inflammation  of  septic  origin 
for  a  longer  period  than  thirty-six  hours  pus  is  almost  invariably 
formed,  and  alveolar  abscess  is  present.  The  diagnostic  symptoms  are 
those  of  acute  pericementitis  described  in  Chapter  XVII.  In  case  any 
marked  inflammatory  disturbance  is  found  about  the  maxillary  region 
either  within  or  without  the  mouth,  examination  of  the  teeth  of  the 
affected  side  should  always  be  made,  as  a  large  percentage  of  such  in- 
flammations are  of  dental  origin.  Any  fistula  existing  in  the  maxillary 
regions,  either  within  or  without  the  mouth,  is  to  be  suspected  as  having 
origin  in  a  septic  pericementitis  of  some  tooth. 

A  soft  silver  probe  is  to  be  passed  along  the  tract  to  determine  its 
direction  and,  if  possible,  which  tooth  is  affected.  As  a  rule,  such  a 
tooth  will  itself  exhibit  objective  evidences  of  abscess  and  the  patient 
will  give  a  history  of  subjective  symptoms — those  of  inflammation  of 
pericementum. 

Shoidd  the  tooth  indicated  as  the  affected  one  be  free  from  caries, 
the  thermal  test  is  to  be  applied  to  indicate  the  vitality  or  the  necrosis 
of  the  pulp.  Should  the  tooth  not  respond  to  applications  of  a  pointed 
piece  of  ice,  it  is  possible  it  may  offer  slight  response  to  applications  of 
heat.  It  is  next  examined  by  light  reflected  from  the  ordinary,  or 
better,  the  electric  mouth  mirror,  when,  if  the  pulp  be  dead,  opacity  of 
the  crown  will  be  detected. 

An  abscess  upon  an  upper  incisor  opening  upon  the  nasal  floor  may 
cause  a  discharge  simulating  that  of  ozena;  an  examination  of  the  nose 
will  reveal  a  teat-like  elevation  upon  the  mucous  membrane  covering 

^  Denial  Surgery. 


488  DENTO-A  L  VEOLA R   A BSCESS. 

the  nasal  floor  and  an  incisor  beneath  will  be  fonnd  carious  and  havino; 
a  putrescent  pulp,  or,  if  non-carious,  a  history  of  traumatic  pericemen- 
titis and  a  present  opacity. 

It  mav  be  mentioned  here  in  connection  with  death  of  the  pulp  from 
traumatism,  that  continued  thread-biting,  biting  very  hard  substances 
such  as  pieces  of  ice,  nuts,  etc.,  may  cause  death  of  the  organ,  presum- 
ably by  thrombosis. 

It  is  possible  that  the  direction  taken  by  the  probe  Avhich  is  passed 
into  the  fistula  will  j)oint  away  from  the  teeth  present,  passing  into  a 
space  from  wdiicli  a  tooth  has  been  extracted.  In  that  event  the  pres- 
ence of  a  root  fragment,  or  ])iece  of  necrosed  process,  may  be  suspected.* 
Should  the  neighboring  teeth  be  excluded  as  causes  of  an  inflammation, 
there  should  be  no  hesitation  in  making  an  exploratory  incision  down 
to  the  end  of  the  probe  which  has  been  passed  into  the  fistula.  Cases 
of  dentigerous  cysts  have  been  detected  in  this  manner.  This  condition 
would,  however,  be  suspected  when  there  was  an  absence  of  a  tooth  or 
teeth  from  the  arch,  no  evidence  past  or  present  of  pericementitis  in 
any  of  the  teeth  of  the  arch,  and  a  cystic  tumor  present  in  the  jaw,  or  it 
may  be  a  fistula  discharging  upon  the  face  after  a  history  of  maxillary 
periostitis. 

Caries  or  necrosis,  although  in  many  cases  the  result  of  septic  apical 
pericementitis,  may  yet  exhil)it  fistula  opening  into  the  mouth,  without 
evident  connection  with  the  teeth.  As  a  rule,  cases  of  necrosis  exhibit 
marked  and  wide  evidences  of  chronic  inflammation  of  the  tissues  over- 
lying the  dead  or  dying  bone ;  there  are  usually  several  fistulae  dis- 
charging from  it. 

Caries  may  have  but  a  single  fistula  and  simulate  closely  ordinary 
alveolar  abscess.  Diagnosis  is  made  by  passing  an  excavator  through 
the  fistula.  Dead  bone  is  readily  detected  by  touch,  it  has  a  rotten  feel ; 
in  caries  the  instrument  may  be  passed  through  the  dead  bone  in  various 
directions,  and  a  characteristic  dead  sound  is  elicited  by  tapping  upon  it. 
Careful  examination  of  the  teeth  must  be  made  in  all  of  these  cases,  to 
determine  the  condition  of  the  pulp  and  pulp  canals. 

In  passing  an  instrument  through  a  fistula  to  the  apex  of  an  ab- 
scessed root,  where  the  disease  action  has  been  of  long  duration,  it  may 
be  found  that  the  apex  of  the  root  is  denuded  of  pericementum,  and 
roughened — that  is,  the  apical  cementum  is  necrotic  ;  foreign  deposits 
may  be  detected  occupying  portions  of  the  necrotic  area. 

Prognosis. — There  are  several  factors  which  enter  into  the  prognosis 

of  a  tooth  and  its  surroundings  which  are  affected  by  alveolar  abscess. 

First,  the  severity  and  character  of  the  inflammatory  action  and  septic 

invasion.     In  cases  in  which  inflammatory  action  is  localized  and  pre- 

*  See  case — Dr.  Black,  American  System  of  Dentistry,  vol.  i. 


TREATMENT.  489 

sentiiig  none  or  but  little  febrile  disturbance  the  prognosis  is,  as  a  rule, 
favorable  ;  but  a  slight  amount  of  tissue  necrosis  occurs.  Should,  on  the 
other  hand,  the  inflammatory  action  proceed  with  volcanic  violence,  it 
is  possible  that  not  only  may  the  pericementum  suffer  extensively,  but  a 
considerable  p<irtion  of  the  periosteum  over  the  process  may  be  raised 
from  the  bone  during  the  escape  of  the  pus.  Should  this  separation  of 
periosteum  be  maintained  for  more  than  a  few  hours,  the  underlying 
bone  may  suffer  to  the  extent  of  necrosis.  In  case  of  marked  lymphatic 
involvement,  the  neighboring  glands  being  sM'ollen  and  tender,  or  even 
the  skin  over  them  exhibiting  evidences  of  glandular  inflammation 
beneath,  more  or  less  septic  intoxication  will  probably  occur,  and  un- 
less the  focus  of  infection  be  promptly  sterilized,  septicemia  is  to  be 
feared. 

"  Should  evidences  of  diffuse  cellulitis  occur,  indicating  the  invasion 
of  streptococci  into  the  adjacent  soft  tissues,  it  is  a  danger  signal  of 
threatening  pyemia.'  Heath"  records  a  case  of  oedema  of  the  glottis  due 
to  the  involvement  of  the  connective  tissues  about  the  glottis  in  the 
oedema  accompanying  a  devek)ping  abscess  upon  a  lower  molar. 

The  })rognosis  is  good  in  a  vast  majority  percentage  of  cases,  when 
the  offending  tooth  is  extracted  early  in  tlie  attack,  or  at  its  height ; 
this  applies  even  with  apparently  very  grave  cases ;  still  the  prognosis 
as  to  the  retention  of  the  affected  tooth  is  also  very  good,  unless  the 
abscess  run  a  phagedenic  course.  In  many  of  the  cases  of  chronic 
abscess  having  a  distant  discharge  the  abscess  may  be  cured  and  the 
tooth  retained.  Other  cases  obstinately  refuse  to  heal  so  long  as  the 
offending  tooth  is  present. 

Treatment. 

Treatment  of  Acute  Abscess. — The  general  principles  of  treat- 
ment of  alveolar  abscess  are  those  for  the  treatment  of  abscess  in  any 
part ;  the  details  are  of  course  modified  in  accordance  with  the  anatom- 
ical peculiarities  of  the  part  to  be  acted  upon.  These  principles  are 
the  removal  of  all  dead  matter,  together  with  the  active  causes  of  the 
inflammation  and  suppuration,  /.  e.  micro-organisms  and  their  products, 
and  the  induction  of  a  tissue  regeneration  which  shall  serve  to  restore 
parts  lost  through  the  formation  of  the  abscess.  The  therapeutic  means 
applied  are  instrumental  and  medicinal.  The  instrumental  are  the 
instruments  employed  to  gain  access  to  the  focus  of  disease  action,  and 
those  applied  in  the  mechanical  removal  of  dead  parts.  The  medicinal 
measures  include  the  agents  employed  to  wash  out  the  abscess  tract ; 
second,  those  applied  to  destroy  the  active  causes  of  the  suppuration  ; 

^  See  case — Dr.  E.  C.  Kirk,  Proc.  Odontological  Society  of  Pennsylvania,  1892. 
"  Injuries  and  Diseases  of  the  Jaws,  3d  ed. 


490  DENTO-ALVEOLAR  ABSCESS. 

tiiird,  the  remedies  ;ip])lie(l  to  induce  new  tissue  orowth  ;  and  next,  those 
employed  to  maintain  asepsis  until  the  heahng  process  is  complete. 

The  great  primary  objects  in  the  management  of  acute  alveolar 
abscess  are  four :  First,  if  the  case  be  seen  early,  to  use  every  endeavor 
to  abort  the  inflammation,  as  described  in  Chapter  XVII.  Second, 
to  limit  as  far  as  possible  the  extent  of  pus  formation,  hence  tissue 
destruction  ;  third,  the  earliest  possible  evacuation  of  the  pus  which  has 
formed  ;  fourth,  the  thorough  sterilization  of  the  abscess  cavity  and  its 
walls. 

Cases  when  seen  may  be  at  any  stage  of  the  disease  process  from  an 
incipient  pericementitis  to  the  establishment  of  a  fistula.  The  treatment 
of  the  early  cases  is  that  of  pericementitis.  In  all  of  these  cases  one  fact 
is  never  to  be  forgotten  :  that  the  pulp  canals  are  the  centres  of  infec- 
tion, and  the  more  quickly  and  thoroughly  they  are  drenched  with 
powerful  antiseptics  the  more  limited  will  be  the  inflammatory  action 
both  in  degree  and  extent,  and  the  more  limited  will  be  the  pus  forma- 
tion. Attempts  are  therefore  made  to  enter  and  sterilize  cavities  pari 
passu  with  the  antiphlogistic  measures  applied  to  abort  or  limit  inflam- 
matory action. 

Treatment  of  Abscess  without  Fistula. — Abscess  has  been  de- 
scribed by  the  older  surgical  pathologists  as  the  process  through  which 
Nature  rids  herself  of  an  irritant.  This  is  in  a  measure  true,  but  it  is 
essentially  a  destructive  and  not  a  conservative  process.  Nature  does 
rid  herself  of  the  irritant  through  suppuration  ;  but  it  is  done  at  the 
expense  of  tissue  loss,  and  the  wise  surgeon  endeavors  to  remove  the 
irritant  and  limit  the  destruction.  After  the  inflammatory  action  has 
persisted  at  its  height  for  twenty-four  hours,  pus  is  probably  present 
in  the  tissues  of  the  apical  region ;  if  immediate  exit  be  given  to  the  pus 
the  inflammatory  symptoms  will  subside.  If  the  tooth  be  not  so  sensi- 
tive as  to  preclude  touch  upon  it,  an  endeavor  is  made,  after  washing 
the  pulp  chamber  with  powerful  antiseptics,  to  pass  a  very  fine  Donald- 
son's bristle  through  the  apical  foramen.  In  many  cases  this  may  be 
done;  the  pus  escaping  through  the  canal,  the  inflammatory  symptoms 
begin  to  subside.  This  is  a  case  of  acute  blind  abscess  ;  its  treatment 
will  be  first  discussed. 

The  conditions  existing  are  more  or  less  remnants  of  pulp  tissue 
undergoing  putrefactive  decomposition ;  the  contents  of  the  dentinal 
tubules  are  also  in  process  of  dissolution.  Beyond  the  apical  foramen 
is  a  fibrous  tissue  containing  bloodvessels  and  nerves,  in  the  meshes  of 
which  tissue  pus  is  forming.  Beyond  the  spots  of  suppuration,  the 
tissues,  which  are  in  small  part  fibrous  but  are  mainly  osseous,  are  the 
seat  of  inflammation. 

The  pus  evacuated,  the  parts  tend  to  spontaneous  recovery  provided 


TREATMENT.  491 

the  sources  of  irritation  be  removed.  The  first  step  in  sterilization  is 
the  destruction  of  putrescent  matter  in  the  pulp  canals.  If  the  tooth 
be  sore  after  evacuation  of  the  pus  through  the  apical  foramen,  the 
patient  is  directed  to  use  repeatedly  an  antiseptic  mouth-wash,  3  per 
cent,  pyrozone  or  any  of  the  solutions  of  hydrogen  dioxid,  and  report 
in  a  few  hours,  when  the  broach  is  again  passed  through  the  apex  of 
the  root,  the  canal  syringed  out  M'ith  hydrogen  dioxid  and  dismissed  for 
twenty-four  hours,  when  the  inflammatory  symptoms  will  have  so  far 
subsided  as  to  permit  working  upon  the  tooth.  At  this  sitting,  a  slight 
flow  of  pus  will  still  be  found ;  the  canals  are  syringed,  rubber  dam 
applied,  but  never  with  a  clamp  on  the  affected  tooth.  Sodium  di- 
oxid either  dry  or  in  50  per  cent,  solution  is  placed  in  the  canals,  and 
frequent  re-applications  made.  At  the  expiration  of  about  a  half-hour 
the  canals  and  abscess  cavity  are  syringed  out  with  an  acid  solution  of 
hydrogen  dioxid,  and  dried.  The  canals  will  now  be  sterilized  and  also 
the  general  abscess  cavity.  It  is  possible,  however,  and  probable,  that 
organisms  may  still  occupy  the  deeper  recesses  of  the  tissue  bounding 
the  abscess  cavity.  The  parts  forming  the  abscess  wall  are  of  com- 
paratively low  vitality  and  may  not  dispose  of  organisms  present  as 
would  be  done  in  more  vascular  tissues.  It  is  the  usual  practice,  there- 
fore, to  apply  to  them  a  powerful  antiseptic  :  campho-phenique,  Dr. 
Black's  1,  2,  3  mixture,  and  lysul  are  all  admirable  agents  in  this  par- 
ticular ;  they  are  pumped  into  the  abscess  sac  as  well  as  possible,  and 
the  excess  in  the  canals  wiped  away  with  wisps  of  cotton. 

There  will  be,  immediately  following  this  operation,  a  greater  or 
less  amount  of  exudation  from  the  abscess  walls,  which  diminishes  as 
granulation  proceeds  about  the  apex  of  the  root.  The  condition  is  one 
of  granulating  ulcer.  An  escape  is  provided  for  this  exudation  by 
leaving  the  dried  canals  unfilled  for  twenty-four  hours,  when  a  loose 
cotton  dressing  may  be  applied,  hermetically  sealing  the  cavity  com- 
municating with  the  saliva  after  each  dressing.  In  two  days  the  dress- 
ing is  removed,  always  sterilizing  the  tooth  walls  and  isolating  it  when 
the  cavity  is  to  be  opened.  On  the  third  day  a  larger  dressing  of 
cotton,  dipped  in  campho-phenique  and  wrung  out,  may  be  applied. 
After  two  days,  should  the  cotton  exhibit  little  or  no  evidence  of  exuda- 
tion, a  firmer  dressing  is  applied,  to  remain  about  four  days  ;  the  next 
dressing  remains  a  week,  when  the  abscess  cavity  should  be  filled  with 
tender  granulations.  Pending  the  organization  of  the  granulation  tissue 
there  is  probably  no  better  canal  filling  than  salol  having  a  core  of 
gutta-percha.  It  is  unirritating  and  may  be  a})plied  without  causing 
irritation.  Dilute  solutions  of  formaldehyd  have  been  found  to  be 
extremely  useful  in  this  class  of  cases  as  Avell  as  in  all  cases  involving 
sterilization  of  the  pulp  canal.     The  high  antiseptic  value  of  formalde- 


492  DENTO-ALVEOLAR  ABSCESS. 

hytl  and  its  great  penetrating  power  place  it  among  the  most  satisfactory 
agents  in  the  dental  pharmacopoeia.  For  the  treatment  of  root  canals 
with  apical  pericementitis  a  wisp  of  cotton  moistened  with  a  5  per 
cent,  solution  of  formalin  (the  40  per  cent,  solution  of  the  gas  in 
water)  and  sealed  in  the  canal  will  in  a  few  hours  completely  sterilize  it, 
so  that  usually  the  canal  may  be  permanently  closed  within  twenty-four 
hours.  Rarely,  a  second  dressing  is  required.  Stronger  solutions  of 
formalin  are  irritating  and  should  be  avoided,  as  they  may  cause 
necrosis  if  used  beyond  the  strength  stated,  or  even  in  that  strength 
if  used  in  too  large  quantity  or  too  frequently. 

Should  the  effort  to  enter  the  apical  region  through  the  canal  fail,  and 
pus  be  present,  an  entrance  should  be  eifected  through  the  gum.  At  a 
point  on  the  gum  immediately  overlying  the  apex  of  the  affected  root, 
a  pointed  bistoury  is  quickly  thrust  down  to  the  bone,  the  bleeding  is 
encouraged  by  the  use  of  hot  water  for  several  minutes,  when  a  pellet 
of  cotton  which  has  been  dipped  into  95  per  cent,  carbolic  acid  is  laid 
against  the  periosteum  at  the  bottom  of  the  cut.  In  a  few  seconds  a 
spear  drill  driven  by  the  engine  is  passed  through  the  bone  into  the 
tissues  of  the  a])ical  region.  Any  bleeding  which  may  occur  is  encour- 
a^ed  as  above  mentioned.  For  washing;  the  incisions  and  the  abscess 
in  such  cases  there  is  no  agent  more  acceptable  than  a  20  })er  cent,  solu- 
tion of  phenol  sodique,  it  being  both  sedative  and  antiseptic.  A  thread 
of  floss  silk  dipped  in  carbolic  acid  is  passed  into  the  fistula  to  the  seat 
of  abscess,  its  projecting  edge  lying  upon  the  gum  ;  this  will  prevent  too 
rapid  a  healing  of  the  fistula.  The  case  now  resembles  an  abscess  with 
a  fistulous  opening,  the  next  variety  of  acute  alveolar  abscess  ;  the  treat- 
ment for  both  is  the  same. 

Treatment  of  Abscess  with  Fistula. — Cases  of  acute  alveolar 
abscess  discharging  through  a  fistulous  opening  are  either  seen  when 
the  pus  has  perforated  the  bone  and  is  making  its  exit  through  the  soft 
tissues,  or  in  cases  where  the  inflammatory  symptoms  run  high,  the 
usual  methods  of  aborting  the  inflammation  having  failed,  pus  forms 
and  the  abscess  discharges  rapidly,  it  may  be  within  thirty-six  hours,, 
The  use  of  pepper  plasters  and  like  devices  to  induce  pointing  of  an 
abscess  are  irrational ;  they  render  no  service  which  cannot  be  per- 
formed better  and  more  expeditiously  by  an  incision  made  down  to 
the  bone  by  means  of  a  sharp  bistoury.  In  all  cases  of  acute  apical 
pericementitis  where  the  swelling  of  the  gum  is  marked,  an  early  and 
deep  incision  is  useful  and  advisable.  If  pus  be  already  formed  and 
the  abscess  pointing,  escape  is  afforded  it ;  if  the  pus  have  not  yet  per- 
forated the  periosteum  that  structure  receives  early  relief  from  a  condi- 
tion which  might  threaten  it.  The  greater  the  swelling  the  more 
imperative  is  the  necessity  for  this  incision,  which  must  be  freely  made. 


TREATMENT. 


493 


Fig.  470. 


A  sharp  curved  bistoury  is  held  as  a  pen,  its  point  directed  always 
toward  the  bone,  and  is  passed  boldly  down  to  the  bone  immediately 
over  the  apex  of  the  root. 

Inflammatory  symptoms,  as  a  rule,  subside  promptly  as  soon  as  exit 
is  afforded  the  pus.  As  soon  as  the  tooth  may  be  operated  upon,  its 
canals  are  to  be  treated  as  virulently  and  deeply  infected  centres,  opened 
freely  and  sterilized  with  the  utmost  thoroughness.  The  usual  and 
satisfactory  method  of  accomplishing  this  is  by  means  of  a  50  per  cent, 
solution  of  sodium  dioxid ;  after  which  a  stout  syringe  filled  with  3 
per  cent,  pyrozone  is  to  have  its  contents  driven  forcibly  through  the 
abscess  tract,  the  application  to  be  repeated  until  the  peroxid  comes 
aw^ay  clear.  A  few  drops  of  campho-phenique  or  Dr.  Black's  1,  2,  3 
mixture  are  placed  in  the  pulp  canal  by  means  of  Flagg's  dressing 
pliers.  This  may  be  drawn  into  the  abscess  sac  along 
its  tract,  emerging  at  the  fistulous  opening,  by  a  little 
device  of  Dr.  T.  M.  Hunter.'  One  of  the  rubber  cups 
used  for  finishing  fillings  and  cleaning  teeth  is  to  have 
its  tool  opening  filled  with  gutta-percha,  the  concavity 
of  the  cup  moistened  and  pressed  flat  against  the  gum, 
covering  the  fistula ;  removing  the  pressure  from  the 
centre  of  the  cup  but  keeping  its  edges  closely  in  con- 
tact with  the  gum,  a  suction  is  created  drawing  the 
medicament  through  the  abscess  tract.  The  writer  has 
used  these  cups,  but  mounted  on  a  No.  300  mandrel 
(Fig.  470),  for  this  purpose  for  several  years  ;  indeed 
the  discovery  that  Dr.  Hunter  had  employed  and  ad- 
vised it  as  a  means  of  emptying  abscess  cavities  was  a 
gratifying  surprise,  as  he  states  that  they  serve  this 
purpose  admirably. 

The  sterilized  canals  are  now  to  be  thoroughly  filled  with  cotton  twists 
or  gilling  twine  which  has  been  moistened  with  the  last-named  antisep- 
tic, or  5  per  cent,  formalin,  the  crown  cavity  sealed,  and  the  case  dis- 
missed. In  twenty-four  hours,  only  a  slight  serous  exudate  should  be 
pressed  from  the  fistula.  In  a  week  the  abscess  cavity  should  be 
healed.  In  that  time  a  permanent  canal  filling  may  be  inserted,  but  it 
is  wiser  to  defer  the  filling  of  the  crown  cavity  for  some  time — that  is, 
if  it  is  to  be  filled  with  cohesive  gold. 

In  case  of  acute  abscess  where  marked  inflammatory  symptoms  with 
involvement  of  neighboring  parts  persists  after  the  evacuation  of  the 
pus,  the  gum  overlying  the  tooth  being  purplish  and  tumid,  the  tooth 
very  loose,  and  no  diminution  of  the  attendant  fever,  neighboring 
structures  in  addition  to  the  tooth  are  in  danger,  and  the  latter  should 

^  Dental  Cosmos,  vol.  xxxiv.  p.  82. 


494  DENTO-ALVEOLAR   ABSCESS. 

be  extracted.  An  early  and  free  incision  will  freqnently  avert  this  con- 
dition and  necessity  for  extraction. 

Shonld  the  case  when  first  seen  exliibit  marked  evidences  of  involve- 
ment of  the  tissues  of  the  face,  a  threatening  of  the  abscess  toward 
pointing  on  the  face,  prompt  and  active  measures  are  necessary.  As  a 
rule  in  these  cases  the  ]iornicioiis  domestic  practice  of  applying  ponltices 
to  the  face  has  been  followcMl,  and  in  consequence  the  tissues  of  the 
cheek  are  distended  and  softened,  lessening  the  suffering  but  inducing 
the  flow  of  ])us  along  the  line  of  softening.  Compresses  wet  with  lead- 
water  and  laudanum — 

I^.  Plumbi  subacet.,  3J  ; 

Tr.  opii,  s}  ; 

Aqu:e,  Oj.— M. 

should  be  laid  upon  the  face,  and  an  incision  made  at  the  line  of  junc- 
tion of  the  cheek  with  the  gum,  down  to  the  bone  over  the  ai)ex  of 
the  root.  As  a  rule,  in  these  cases  the  pus  has  found  its  way  into  the 
tissues  of  the  cheek,  but  drains  through  the  incision  ;  a  cut  must  always 
be  made  away  from,  not  toward  the  cheek,  to  avoid  cutting  the  facial 
artery  or  any  of  its  branches.  Opening  upon  the  face  may  be  averted 
by  this  means,  even  when  the  pus  is  beneath  the  skin.  The  danger  of 
inclusion  of  the  duct  of  Steno  should  be  borne  in  mind  should  the  case 
be  one  of  abscess  upon  an  upper  molar,  and  energetic  measures  pursued 
to  prevent  the  establishment  of  that  annoying  trouble,  salivary  fistula. 

When  fluctuation  of  the  inflammatory  tumor  u]ion  the  face  becomes 
evident,  indicating  that  an  external  opening  must  be  made,  it  is  prefer- 
able that  it  be  made  with  a  sharp  knife  and  not  by  sup])uration.  Scars 
left  by  abscesses  discharging  spontaneously  are  irregular  and  disfiguring, 
those  following  clean  incision  are  but  a  line.  A  curved  bistoury  is  used 
to  transfix  the  summit  of  the  swelling,  the  knife  is  then  carried  outward, 
making  an  incision  about  an  inch  long.  In  this  as  in  all  cases  of  abscess 
where  pus  is  detected  the  indication  is  to  give  it  immediate  exit. 

It  occasionally  occurs  that  abscess  may  be  found  upon  the  lateral 
aspect  of  a  tooth  containing  a  vital  pulp.  The  tooth  is  free  from 
caries,  and  is  perfectly  translucent.  The  most  usual  situations  of  these 
abscesses  are  upon  the  labial  faces  of  the  anterior  teeth  and  the  buccal 
faces  of  the  molars,  between  the  gingival  margin,  which  may  be  intact, 
and  the  apex  of  the  root.  As  a  rule  the  evacuation  of  the  pus  and 
dressing  with  antiseptics  causes  a  speedy  disappearance  of  the  abscess. 
Left  to  themselves  they  discharge  as  a  rule  at  the  gum  margin.  They 
are  a  frequent  associate  of  the  condition  graphically  described  by  Dr. 
G.  V.  Black  as  phagedenic  pericementitis.  Believers  in  the  gouty 
origin  of  this  disorder  note  their  occurrence  in  gouty  patients.^     In 

1  Typical  cases  are  recorded  in  Proc.  Academy  of  Stomatology  of  Plilladelphia,  1S95. 


TREATMENT.  495 

these  cases  the  abscess  is  attended  by  more  or  less  destruction  of  the 
pericementum.  Cases  may  be  seen  in  which  the  abscess  involves  the 
tissues  near  the  apex  of  the  root,  the  pulp  being  vital ;  its  death,  how- 
ever, will  doubtless  result  from  the  invasion. 

Acute  apical  abscess  may  discharge  at  the  margin  of  the  gum,  follow- 
ing the  pericementum.  These  cases  are  to  be  treated  as  abscess  with 
fistula.  In  some  cases  subsequent  to  the  treatment  of  the  abscess  there 
appears  to  be  a  restoration  of  the  pericementum  lost  in  the  formation  of 
the  fistula.  In  others  a  permanent  loss  of  tissue  results.  This  mode 
of  discharge  is  common  about  dead  roots  which  have  been  in  the  jaw 
crownless  for  a  long  period ;  a  resorption  of  alveolar  process  has 
occurred  and  the  root  is  retained  by  fibrous  tissue.  The  treatment  in 
these  cases  is  that  accorded  any  and  all  roots  which  may  not  be  made 
serviceable — extraction . 

Treatment  of  Chronic  Abscess. — For  purposes  of  treatment, 
chronic  abscesses  are  divided  into  two  classes  :  those  discharging  through 
the  pulp  canal,  wdiat  are  known  as  blind  abscesses ;  second,  those  dis- 
charging upon  the  gum,  at  the  neck  of  the  tooth  or  in  fact  at  anv  point, 
through  a  fistula. 

The  usual  condition  existent  with  the  blind  abscess,  is  a  cavitv 
which  may  have  any  volume,  its  diameters,  however,  rarely  exceeding 
three-eighths  of  an  inch  ;  this  cavity  is  bounded  upon  all  sides  by  a 
fibrous  capsule,  analogous  to  the  indurated  surroundings  of  an  ulcer;  the 
wall  represented  l:>y  the  cementum  of  the  affected  tooth  mav  be  devoid 
of  fibrous  tissue,  the  pericementum  being  necrotic.  The  pulp  chamber 
is  the  centre  of  infection  ;  the  abscess  cavity  is  the  habitat  of  l^acteria, 
which  cause  the  peptonization  of  the  inflammatory  exudate  from  the 
wall  of  circumvallation,  and  destroy  the  exudation  corpuscles,  thus 
producing  a  continued  pus  formation.  The  observation  and  statement 
of  Dr.  Black  have  been  quoted  above,  wherein  he  states  that  gravity 
largely  determines  the  direction  pursued  by  the  pus  in  chronic  abscess. 
This  tendency  will  be  found  to  exist  with  the  blind  varietv  also. 

The  tendency  of  long-continued  pus  formation  about  the  roots  of  the 
upper  teeth  will  be  to  progress  along  the  pericementum,  resulting  in  a 
molecular  necrosis  of  that  structure  from  the  apex  downward.  The 
condition  is  represented  in  Fig.  471.  The  extent  to  which  the  apex  of 
the  root  projects  into  a  cavity  increases  with  the  progress  of  the  necrotic 
process. 

In  the  lower  teeth,  the  influence  of  gravity  carries  the  suppurative 
process  away  from  the  apex  of  the  root,  the  abscess  cavity  increasing 
downward  (Fig.  472). 

If  the  case  be  seen  shortly  after  the  subsidence  of  the  inflammatory 
attack  which  may  have  ushered  in  the  suppurative  process,  the  cavity 


496 


DENTO-A  L  VEOL  A  R  A  BSCESS. 


may  be  very  limited  in  size,  only  a  trifling  amount  of  the  perieementum 
being  destroyed. 

It  is  advisable  in  these  cases,  after  thorough  sterilization  of  the  canals 
and  dentin  by  means  of  sodium  dioxid  or  formalin,  to  increase  the  size  of 
the  natural  drainage-tube,  by  enlarging  the  pulp  canal ;  a  fine  Donaldson 

Fig.  471.  Fig.  472. 


Chronic  blind  abscess  of  upper  incisor,  showing  Chronic  blind  abscess  u|)On  lower  tooth, 

tendency  of  pus  to  progressively  destroy  peri-  showing  tendency  of  pus  to  sink  into 

cementum  owing  to  the  Influence  of  gravity.  the  substance  of  the  lower  maxilla 

owing  to  the  influence  of  gravity. 

cleanser  should  pass  freely  through  the  apical  foramen.  The  abscess 
cavity  is  now  forcibly  and  thoroughly  syringed  out  with  3  ])er  cent, 
pyrozone.  It  is  advisable  after  effervescence  ceases  to  mechanically 
withdraw,  or  aspirate,  the  contents  of  the  abscess.  This  may  be  readily 
done  by  passing  the  point  of  a  syringe  into  the  canal,  filling  around  it 
with  gutta-percha  and  withdrawing  the  piston,  when  the  contents  of  the 
abscess  will  flow  into  the  syringe.  Any  instrument  (syringe)  employed 
for  this  purpose  should  soak  for  hours  in  an  antiseptic  before  using  it 
in  other  cases  (a  20  per  cent,  solution  of  phenol  sodique  is  an  excellent 
sterilizing  agent) ;  the  same  syringe  should  never  be  used  for  any  other 
purpose.  A  small  amount  of  25  per  cent,  pyrozone,  ethereal,  may  now 
be  placed  in  the  canals  and  pumped  into  the  abscess  cavity ;  then  canals 
and  sac  are  dried  by  means  of  warm  blasts,  and  a  wisp  of  cotton  dipped 
in  campho-phenique  and  wrung  out  is  packed  in  the  canal.  The 
patient  reports  the  day  following,  and  if  no  discomfort  be  felt  the  tooth 
remains  closed  until  the  following  day.  If  upon  opening  the  tooth  no 
evidence  of  exudation  is  seen,  and  no  effervescence  occurs  upon  applica- 
tion of  3  per  cent,  pyrozone,  the  drying  and  dressing  are  renewed,  to 
remain  about  three  days.  If  any  evidence  of  pus  be  detected,  the  canals 
and  abscess  are   syringed  with  weak  pyrozone,  and  a   small   amount 


TREATMENT.  497 

of  campho-phenique,  Dr.  Black's  1,  2,  3  mixture,  or  myrtol  may  be 
pumped  into  the  abscess,  and  by  repeated  blowing  of  warm  blasts  driven 
into  all  parts  of  the  cavity.  In  tw^enty-four  hours  a  slight  serous  flow 
should  be  observed,  but  if  after  three  days  any  evidence  of  pus  be  de- 
tected, it  is  the  signal  to  establish  an  external  fistula.  This  is  done  in 
the  manner  before  described.  The  treatment  is  now  the  same  as  that 
for  the  next  class  :   chronic  abscesses  having  fistulous  opening. 

Chronic  Abscess  with  Fistulous  Opening-. — In  these  cases  the 
canals  are  opened  and  sterilized  as  in  all  others  by  the  powerful  anti- 
septics named.  The  abscess  tract  is  syringed  out  with  3  per  cent,  pyro- 
zone  until  bubbling  at  the  external  orifice  ceases.  The  canals  are  filled 
with  campho-phenique,  or  the  1,  2,  3  mixture,  after  the  dressing-pliers 
method,  and  drawn  into  and  through  the  abscess  cavity  and  tract  by 
means  of  the  rubber-cup  device  already  mentioned.  In  cases  in  which 
the  rubber-cup  device  fails  to  cause  a  flow  of  the  medicament  from  the 
pulp  chamber  out  through  the  fistulous  tract,  the  result  may  be  attained 
by  filling  the  canals  and  pulp  chamber  wdth  the  fluid  desired ;  for 
example,  campho-phenique  or  strong  carbolic  acid,  and  then  placing 
over  the  cavity  a  pellet  of  unvulcanizcd  caoutchouc  or  warmed  and  soft- 
ened gutta-percha  base  plate  and  exerting  strong  pressure  upon  it  with 
a  ball-end  burnisher  just  enough  smaller  than  the  cavity  to  force  the 
material  well  into  the  pulp  chamber.  This  will  cause  the  medicine  to 
flow  out  at  the  fistulous  opening,  where  in  the  case  of  carbolic  acid  its 
presence  will  be  manifested  by  its  coagulating  effect  upon  the  margins 
of  the  fistulous  orifice. 

The  canals  are  to  be  temporarily  filled  with  cotton  saturated  with  an 
antiseptic,  and  as  a  rule  the  case  proceeds  rapidly  to  recovery.  Fresh 
cleansing  and  dressing  are  indicated  if  all  evidences  of  inflammatory 
action,  seen  in  the  gum  color,  are  not  absent  in  three  days ;  in  a  week 
the  external  fistula  should  be  closed. 

If  after  a  week  the  fistula  remain  open,  discharging 
serum,  a  sterilized  excavator  is  passed  through  the 
fistula  and  it  may  detect  denudation  and  roughness  of 
the  apical  cementum.  After  a  root  has  been  the  seat 
of  chronic  apical  abscess  for  a  long  period,  not  only 
may  the  apical  pericementum  be  destroyed  (Fig.  473), 
but  the  cementum  itself  may  become  saturated  with 
the  products  of  decomposition  and  invaded  by  septic  chronic  abscess :  show- 
organisms.     It  is  not  uncommon  to  find  deposits  of      ing   denudation    of 

!!•  xijij  J.  01  apex  of  root  (a  to  6), 

calculi  upon  the  denuded  cementum.  feuch  an  apex  ^j^j^  deposits  of  cai- 
is  the  source  of  constant  irritation  ;  it  is  a  foreign  cuius  upon  cemen- 
body,  and  is  to  be  removed. 

The  operation  of  removal  is  technically  known  as  amputation  of  the 

32 


498  DENTO-ALVEOLAR  ABSCESS. 

apex.  The  canal  thoroughly  sterilized  is  to  be  solidly  filled  with  gutta- 
percha. A  vertical  incision  is  made  which  includes  the  fistula  and 
exposes  the  process ;  the  opening  through  the  process  is  enlarged,  by- 
sweeping  around  its  borders  a  large  dentate  bur.  The  incision,  open- 
ing and  abscess  cavity  arc  now  packed  with  cotton  saturated  with  phenol 
sodique,  until  all  bleeding  ceases. 

The  necrosed  cementum  is  now  exposed  ;  a  small  and  extremely  sharp 
fissure  bur,  driven  rapidly,  is  laid  against  the  distal  wall  of  the  root  and 
a  constant  pressure  up(^n  the  bur  maintained  luitil  the  dead  part  is  ampu- 
tated. A  sharp  scaler  may  now  be  employed  to  round  the  edges  of  the 
root  and  make  the  cut  surface  smooth. 

The  cavity  is  syringed  with  phenol  sodique,  to  thoroughly  remove 
all  blood-clots — favorable  breeding-grounds  for  organisms ;  as  a  final 
measure  the  walls  are  touched  with  campho-phenique,  and  the  edges  of 
the  incision  brought  together,  using  if  necessary  a  stitch  to  unite  the 
upper  edges.  In  the  abscess  cavity  iodoform  or  nosophen  gauze  is  to 
be  packed,  and  renewed  in  a  couple  of  days.  For  a  week  the  patient 
is  directed  to  employ  repeatedly  a  mouth-wash  of  3  per  cent,  pyrozone. 
No  attempt  should  be  made  to  fill  such  a  tooth  with  cohesive  foil  for 
several  months. 

In  some  of  the  cases  of  anomalous  root  form,  such  as  a  sharp  bend 
upon  the  upper  end  of  the  root,  and  which  renders  it  impossible  to 
gain  access  to  the  apex  of  the  root  even  through  the  aid  of  sulfuric  acid, 
it  may  be  necessary  to  treat  the  abscess  through  the  fistulous  opening. 
The  roots  are  sterilized  and  cleansed  to  as  great  a  depth  as  possible  by 
the  aid  of  sulfuric  acid  and  fine  cleansers,  and  the  endeavor  made  to 
force  hydrogen  dioxid  through  the  apical  foramen  and  out  of  the  fistula 
by  means  of  a  syringe.  The  cavity  of  the  crown  is  filled  Avith  pink 
gutta-percha,  and  through  it  the  nozzle  of  a  syringe  filled  Avith  3  per 
cent,  pyrozone  is  thrust,  well  up  the  canal.  The  piston  of  the  syringe 
is  forced  down  ;  it  may  be  the  solution  will  appear  at  the  opening  of 
the  fistula,  or  it  may  be  the  solution  will  fail  to  penetrate  the  fora- 
men and  its  backward  pressure  will  force  the  gutta-percha  from  posi- 
tion. In  that  event  myrtol  is  placed  in  the  canal,  which  is  filled  with 
thread  holding  the  same  material.  Three  per  cent,  pyrozone  is  injected 
into  the  abscess  cavity  through  the  fistula,  until  eflFervescence  ceases. 
The  nozzle  of  a  minim  syringe  (Fig.  441).  charged  with  campho- 
phenique  or  the  1,  2,  3  mixture  is  passed  into  the  abscess  sac,  and  a 
couple  of  drops  deposited.  In  very  many  cases  the  abscess  will  then 
proceed  to  recovery.  The  treatment  should  be  repeated  if  necessary. 
If  several  dressings  applied  at  intervals  of  a  week  do  not  cause  a 
disappearance  of  pus  formation,  amputation  of  the  offending  portion 
of  the  root  will  be  necessary.     An  heroic  method  of  treating  chronic 


TREATMENT.  499 

abscesses  which  obstinately  refuse  to  heal  is  by  extraction  and  replanta- 
tion. The  method  applies  alone  to  single-rooted  teeth,  although  it  has 
been  successfully  performed  upon  molars. 

The  patient's  mouth  is  to  be  sterilized,  and  the  tooth  extracted.  It 
is  immediately  placed  in  a  solution  of  1  :  1000  mercuric  chlorid  at  a 
temperature  of  120°  F.  It  has  been  repeatedly  asserted,  however,  with- 
out satisfactory  demonstration,  that  the  cells  of  the  deeper  layer  of  the 
pericementum  and  the  cementoblasts,  and  also  the  cement  corpuscles 
retain  their  vitality  for  some  period  after  extraction,  and  immediate 
replantation  results  in  a  re-establishment  of  the  physiological  union 
between  the  tooth  and  alveolus.  It  is  certain  that  means  and  measures 
which  are  necessary  to  thoroughly  sterilize  the  tooth  before  its  reinser- 
tion Avould  be  fatal  to  any  cellular  vitality  which  might  exist  in  the 
cementum  and  its  covering. 

The  pulp  canal  is  opened  from  its  apex  and  cleaned  out  with  canal 
cleansers,  and  pyrozone  25  per  cent,  placed  in  the  canal,  where  it  is  al- 
lowed to  remain  for  some  time.  In  the  meantime  the  socket  from  which 
the  tooth  has  been  removed  is  syringed  out  with  pyrozone,  and  should 
the  pericementum  not  be  adherent  to  the  tooth,  the  depth  of  the  socket 
is  scraped  by  means  of  large  spoon  excavators  to  remove  the  tissues 
implicated  in  the  abscess.  The  cavity  is  washed  out  with  pyrozone, 
and  a  pledget  of  cotton  which  has  been  dipped  in  campho-phenique  is 
placed  in  the  socket  at  its  bottom.  The  tooth  is  dried  by  means  of 
warm  air ;  the  soft  tissues,  if  any  be  present,  at  the  apex  are  cut  away 
for  about  one-eighth  of  an  inch.  The  canal  is  filled  with  gutta-percha 
or  solidly  filled  with  gold,  the  end  of  the  root  cut  off  as  far  as  it  has 
been  denuded  of  pericementum,  smoothed,  and  returned  to  the  antiseptic 
solution.  The  cotton  is  removed  from  the  tooth  socket,  which  is 
syringed  out  with  3  per  cent,  pyrozone,  and  the  tooth  returned  to  posi- 
tion. It  is  tied  to  the  adjoining  teeth  by  means  of  silk  ligatures  or  held 
in  place  by  an  appropriate  retaining  appliance. 

0(!casionally  the  seat  of  an  alveolar  abscess  may  be  at  the  l)ifurca- 
tion  of  the  roots  of  a  molar.  This  may  occur  upon  vital  teeth  owing 
to  a  foreign  body  being  driven  beneath  the  margin  of  the  gums  and  into 
the  point  of  bifurcation.  In  these  cases  it  is  noted  that  the  inflamma- 
tion affects  the  gum  about  the  neck  of  the  tooth  ;  over  the  apices  of  the 
roots  there  may  be  no  evidences  of  inflammation  ;  pus  forms  and  dis- 
charges quickly.  Syringing  out  the  tract  with  3  per  cent,  pyrozone 
usually  frees  it  from  pus  and  the  offending  substance — it  may  be  a 
bristle  of  a  toothbrush — and  the  case  heals  rapidly. 

Cases  are  seen  in  which  the  gum  attachment  about  the  neck  of  the 
tooth  is  unbroken  ;  and  free  access  may  be  had  to  the  apex  of  each 
root  of    a  tooth    manifestly  sufl'ering  from  acute  pericementitis,  pre- 


500  DENTO- ALVEOLAR  ABSCESS. 

.sumahly  due  to  a  putroscent  ])iil|>.  In  a  day  or  two  a  discharge  of 
})us  may  he  noted  about  tlie  neck  of  the  tooth.  Sueli  teeth  when 
extracted  exhibit  an  unmistakable  abscess  sac  in  the  pericementum  at 
the  bifurcation  of  the  roots.  Wliether  the  pyogenic  organisms  have 
traversed  the  dentin  in  the  bottom  of  the  pulp  chamber  and  the 
cementum  beneath,  and  thus  inaugurated  the  suppurative  j)rocess,  is 
undetermined ;  it  may  be,  however,  that  waste  products  from  this 
source  following  the  channel  named  may  have  saturated  the  cementum 
with  noxious  material  and  caused  the  inflanniiation,  or  the  organisms  may 
have  found  entrance  at  the  gum  margin.  The  diagnosis  of  such  a  con- 
dition is  most  uncertain  before  pus  finds  exit  at  the  gum  margin.  Such 
a  case  is  to  be  treated  by  sodium  dioxid,  full  strength,  ])lac(>d  in  the 
floor  of  the  cavity,  frequently  washed  away  and  renewed  until  the  base 
of  the  pulp  chamber  is  bleached  white.  The  abscess  cavity  is  syringed 
out  with  pyrozone. 

Another  variety  of  abscess  should  receive  mention  :  that  occurring 
about  lower  third  molars,  affecting  the  gum  tissues  partially  enclosing 
the  emerging  crown.  The  gum  overlying  and  surrounding  the  erupting 
tooth  becomes  reddened,  tumid,  and  exquisitely  sensitive  ;  if  the  inflam- 
mation be  not  aborted  by  timely  incision  and  antiseptic  washes,  pus  may 
form,  and  the  gum  acquire  an  ulcerous  appearance.  The  treatment  is 
free  incision,  dividing  the  swollen  gum,  and  syringing  with  3  per  cent, 
pyrozone.  If  there  be  ulcerous  surfaces  they  are  to  be  touched  with  50 
per  cent,  solution  of  trichloracetic  acid. 

Occasionally  the  muscles  of  mastication  may  become  aifected  by  the 
inflammatory  process,  and  inability  to  open  the  jaws  result.  Such  cases 
are  not  uncommon  when  the  eruption  of  the  tooth  is  delayed  by  lack  of 
room  between  the  ramus  of  the  jaw  and  the  second  molar.  The  extrac- 
tion of  this  latter  tooth  may  be  required  before  relief  is  secured. 

Complications  of  Alveolar  Abscess. 

The  complications  of  alveolar  abscess  are  due  in  acute  cases  to  the 
involvement  of  other  tissues  than  those  commonly  affected  in  the  course 
of  abscess  formation  and  discharge.  They  depend  in  great  part  upon 
peculiarities  of  the  anatomical  relations  existing  between  teeth  and  their 
surroundings,  and,  as  anatomical  variations  are  not  uncommon  in  these 
parts,  aberrations  of  disease  process  may  be  found  with  unwelcome  fre- 
quency. An  examination  of  some  of  Dr.  Cryer's  sections  ^  will  exhibit 
in  one  case  the  root  of  a  lower  second  bicuspid  penetrating  the  passage- 
way for  the  inferior  dental  vessels  and  nerves.  It  is  quite  possible  that 
an  abscess  upon  such  a  tooth  discharging  about  the  fibrous  sheaths  of 
^  Proc.  of  American  Dental  Association,  1895. 


COMPLICATIONS   OF  ALVEOLAR  ABSCESS.  501 

these  vessels  might  travel  to  distant  parts — backward  through  the  in- 
ferior dental  foramen,  or  forward  through  the  mental  foramen. 

The  roots  of  molar  teeth  instead  of  having  their  thinnest  bony  cov- 
ering overlying  their  buccal  aspects,  may  have  their  apices  almost  per- 
forating the  lingual  wall  of  the  bone  ;  in  others  the  apex  of  the  root  of 
a  lower  molar  is  found  beneath  the  line  of  insertion  of  the  mylo-hyoid 
muscle.  Abscess  from  such  a  case  as  this  would  probably  discharge  not 
into  the  cavity  of  the  mouth,  but  in  the  submaxillary  triangle.  (See 
the  case  of  Dr.  Cryer's  noted  early  in  the  chapter.)  Dr.  Harrison 
Allen '  records  one  of  these  cases.  The  septic  roots  of  a  lower  third 
molar  were  the  exciting  cause  of  pericementitis,  followed  by  osteitis 
and  maxillary  periostitis.  Pus  found  exit  beneath  the  mylo-hyoid 
muscle  and  gravitated,  forming  a  collection  about  the  hyoid  bone,  and 
from  that  point  passed  upward  upon  the  face  in  the  line  of  the  facial 
artery.  The  abscess  in  addition  pressed  directly  upward  against  the 
floor  of  the  mouth  and  caused  unilateral  glossitis,  from  the  mechanical 
effects  of  which  upon  the  organs  of  respiration  the  patient  died.  The 
duration  of  the  extra-maxillary  complication  was  but  four  days. 

In  the  progressive  resorption  of  the  inner  substance  of  the  superior 
maxillary  bone  which  results  in  the  formation  of  the  maxillary  sinus,  a 
process  which  certainly  continues  longer  in  some  persons  than  in  others, 
the  bony  structures  may  be  removed  to  such  an  extent  that  but  a  thin 
layer  of  bone,  periosteum  and  mucous  membrane  covers  the  apices  of 
the  roots  of  molars.  Dr.  Cryer's  sections  exhibit  two  cases  in  which 
the  excavation  of  the  sinus  has  proceeded  down  between  the  roots  of  an 
upper  molar,  creating  such  a  condition  that  abscess  upon  either  palatal 
or  buccal  roots  must  almost  inevitably  discharge  into  the  sinus.  No 
doubt  many  cases  of  incipient  empyema  of  the  antrum  are  aborted  by 
the  early  extraction  of  abscessed  molars,  the  antral  complication  being 
unrecognized.  It  is  presumable  that  most  of  the  cases  of  empyema  of 
the  antrum  afford  sul)jective  evidence  comparatively  early,  owing  to  the 
lighting  up  of  inflammation   and  purulent  catarrh. 

The  student  is  advised,  in  studying  the  relations  of  the  teeth  with  the 
maxillarv  sinus,  to  a  careful  and  repeated  reference  to  the  sections  of 
Dr.  Cryer.  He  calls  attention  to  a  fact  frequently  overlooked  and  un- 
taught, that  the  orifice  or  opening  connecting  the  maxillary  sinus  with 
the  nasal  passage  is  near  the  roof  of  the  former,  so  that  while  the  patient 
is  in  the  erect  position  collections  of  fluid  must  nearly  fill  the  sinus 
before  there  is  a  discharge.  In  the  recumbent  position,  however,  the 
fluid  escapes  and  may  be  found  in  the  nostril  of  one  side.  This  is 
symptomatic  of  antral  empyema.  In  acute  cases  of  the  antral  disease 
there  is  much  swelling,  wdema  about  the  eyelid,  etc, ;  sharp  lancinating 
'  (iarretson's  Oral  Surgery,  6th  edition. 


502  DENTO-ALVEOLAR  ABSCESS. 

pains  dart  about  the  jaw.  In  the  cln-onic  cases,  large  aeeuniulations  of 
pus  may  occur  and  not  be  detected  until  the  bone  is  thin  and  bulged, 
emitting  a  crackling  sound  upon  })res.sure.  Extraction  of  the  offending 
tooth  furnishes  an  outlet  for  the  pus. 

It  is  usual  to  attempt  the  passage  of  an  instrument  through  the 
pulp  canals  into  the  antrum  and  endeavor  to  preserve  the  tooth.  Such 
a  drainage  is  insufficient ;  the  wall  of  the  antrum  should  be  perforated. 
This  little  operation  is  readily  done  :  At  a  point  about  one-eighth  of  an 
inch  or  more  above  the  apices  of  the  roots  of  the  molars  an  incision  is 
made  through  the  mucous  membrane  of  the  buccal  alveolar  wall,  clear 
to  the  bone  ;  a  spear-pointed  drill,  a  large  one  driven  rapidly  by  the 
engine,  is  passed  instantly  through  the  outer  antral  wall.  The  drill 
is  directed  upward  and  inward.  The  opening  is  made  sufficiently  large 
to  permit  free  irrigation.  Into  the  opening  thus  made  the  point  of  a 
syringe,  perforated  to  sprinkle,  is  placed,  and  the  cavity  washed  out 
with  3  per  cent,  pyrozone  which  has  been  diluted  one-half  and  made 
faintly  alkaline  by  the  addition  of  sodium  dioxid.  As  pointed  out  by 
Dr.  ^y.  H.  Atkinson  many  years  ago,  unless  the  irrigating  fluid  be 
made  faintly  alkaline  it  is  irritating.  As  a  stimulant  injection  to  fol- 
low, Lugol's  solution  (liquor  iodi  compositus,  gtt.  xx  to  the  ounce)  is 
excellent.  The  canal  of  the  tooth  is  to  be  thoroughly  sterilized  and 
filled. 

In  the  treatment  of  other  complications,  if  the  case  be  acute,  the  im- 
mediate extraction  of  the  offending  tooth  and  the  free  use  of  antiseptic 
mouth-washes  will  usually  effect  a  cure.  In  the  treatment  of  chronic 
cases,  if  the  focus  of  infection,  the  pulp  canals,  be  made  antiseptic  and 
the  medicinal  agents  can  be  introduced  into  the  abscess  tract  through- 
out, surprising  cures  may  result,  as  the  literature  of  dentistry  testifies. 

Abscess  upon  Temporary  Teeth. — Among  the  most  trying  classes 
of  cases  with  which  the  dental  operator  is  confronted  are  those  of  peri- 
cemental disturbance  affecting  the  temporary  teeth.  The  operator  is 
torn  by  conflicting  emotions  :  the  desire  to  afford  quick  relief  to  the  little 
sufferers  and  the  hesitancy  or  dread  of  inflicting  the  amount  of  suffering 
necessary  to  relieve  the  acute  pain.  Fortunately  the  pain  is  relatively 
less  than  in  adults  ;  the  tissues  being  softer  the  child  escapes  the  agoniz- 
ing pain  attending  the  rapid  formation  of  pus  in  the  apical  tissues  of  the 
adult.  The  swelling,  redness,  and  febrile  disturbance  are  usually  greater 
in  the  child  than  in  the  adult ;  pus  forms  more  quickly  and  makes  its 
appearance  in  the  gum  sooner.  The  principle  of  treatment  is  the  same 
as  with  the  adult — evacuation  of  the  pus.  The  necessary  incision  may 
be  made  almost  painlessly  by  employing  a  sharp-pointed  bistoury  hav- 
ing a  razor-like  edge.  The  child,  reassured  by  a  gentle  examination 
and  firm  kindness,  is  directed  to  open  the  mouth  and  close  the  eyes, 


COMPLICATIONS  OF  ALVEOLAR  ABSCESS.  503 

Avlien  the  bistoiirv,  held  a??  a  pen,  i.s  pat^sed  quickly  into  the  swell- 
ing. 

The  can'als  of  temporary  teeth  are  to  be  sterilized  first  with  pyrozone, 
next  with  oil  of  cassia,  and  should  be  filled  with  "  balsamo  del  deserto." 
Dr.  W.  H.  White,  to  whom  we  are  indebted  for  the  introduction  of  this 
materia],  states  that  in  roots  of  temporary  teeth  in  which  it  has  been 
placed  the  resorptive  process  is  not  interfered  with. 

Abscess  occurring  upon  temporary  teeth  should  receive  prompt  at- 
tention and  treatment  to  avoid  possible  injury  to  the  permanent  tooth 
beneath ;  this,  however,  does  not  appear  to  be  as  frequent  as  might  be 
sujiposed.  There  is  a  tendency  in  strumous  children  toward  marked 
lymphatic  involvement  attending  alveolar  abscess ;  and  secondary 
abscess  of  the  lymphatic  glands  is  not  uncommon. 

Chronic  abscess  in  the  cachectic  individual  which  may  not  respond 
to  the  usual  local  measures  of  treatment  may  be  materially  benefited 
by  constitutional  treatment.  This  comprises  regulation  of  the  functions 
of  the  alimentary  canal ;  the  use  of  such  foods  as  beef  peptonoids,  mal- 
tose, etc.  Iron  and  arsenic  are  administered  when  the  patient  is,  as  is 
usually  the  case,  anemic.  More  important  than  any  medicinal  thera- 
peutics is  systematic  exercise  in  the  open  air.  Raising  the  bodily  tone 
raises  the  recuperative  power  of  the  tissues,  and  hitherto  resisting  dis- 
ease may  be  conquered. 

Perforated  Roots. — Perforation  of  the  walls  of  a  root  canal  expos- 
ing the  pericementum  occurs,  as  a  rule,  in  consequence  of  two  causes  : 
first,  the  invasion  of  dental  caries  ;  second,  the  injudicious  or  unskilful 
use  of  the  reamer  employed  in  enlarging  canals,  or,  it  may  be,  burring 
through  the  walls  in  the  forming  of  a  socket  for  the  reception  of  the 
post  of  an  artificial  crown. 

The  direct  consequence  of  the  perforation  is  inflammation  of  the 
pericementum,  and  the  usual  result  is  ulceration  of  that  structure.  The 
symptoms  and  their  severity  are,  as  a  rule,  governed  by  the  situation  of 
the  perforation.  If  this  be  at  the  lower  half  (toward  the  crown)  of  the 
root,  there  is  usually  a  proliferation  of  tissue  which  intrudes  upon  the 
pulp  chamber.  This  hypertrophied  tissue  may  increase  in  amount,  a 
resorption  of  the  edge  portion  of  the  process  occur,  and  a  fungous  mass 
bearing  a  close  resemblance  to  fungous  pulp  bulge  into  the  pulp  cham- 
ber. In  fact,  in  many  cases  it  is  impossible  to  distinguish  between 
the  naked-eye  appearance  of  fungous  pulp  and  the  condition  under 
discussion.  The  growth  fills  the  pulp  chamber  and  obscures  the  per- 
foration ;  it  is  in  addition,  in  many  cases,  exquisitely  tender.  In  either 
event,  whether  pul]>  or  hypertrojihied  gum,  it  is  necessary  to  remove 
the  growth. 

A  spray  of  ethyl  chlorid  directed  against  the  mass  is  perhaps  the 


504  DENTO-ALVEOLAB  ABSCESS. 

most  effective  anesthetic  ;  in  a  few  minutes  a  sharp  fine-pointed  lancet  is 
passed  around  the  growth  as  far  as  it  can  be,  and  the  excised  portion 
removed.  An  application  of  tannin  will  check  the  bleeding  ;  pledgets 
of  cotton  dipped  in  tr.  iodin.  are  packed  against  the  remainder  of  the 
growth  and  covered  in  with  cotton  and  sandarac  varnish  for  twenty- 
four  hours.  Tiiis  dressing  is  renewed  from  day  to  day  until,  if  it  be  a 
fungous  gum,  tlu;  margins  of  the  perforation  are  plainly  seen.  The 
canal  is  cleansed,  sterilized,  dried,  and  filled  with  salol  and  gutta-percha, 
or  with  paraffin  and  gutta-percha,  to  about  half  its  depth.  The  re- 
mainder of  the  canal  and  crown  cavity  are  washed  out  with  25  per  cent, 
j^yrozone,  and  a  dressing  of  temporary  sto})ping  applied,  filling  the  per- 
foration and  yet  not  exercising  much  pressure  upon  the  soft  tissues.  In 
two  days  the  temporary  stopping  is  removed  and  the  cavity  is  washed 
out  with  3  per  cent,  pyrozone  and  dried.  A  piece  of  No.  60  gold  is  cut, 
larger  than  the  aperture  ;  this  is  dipped  in  chloro-percha  and  laid  over 
the  perforation.  A  disk  of  gutta-percha  larger  than  the  piece  of  foil  is 
warmed,  laid  upon  the  foil,  and  pressed  against  it,  sealing  it  to  the 
cavity  walls.  The  remainder  of  the  cavity  is  then  filled  with  zinc  phos- 
phate. 

In  case  the  perforation  should  be  nearer  the  apex  of  the  root  the  dif- 
ficulty is  greatly  increased.  Attempts  at  passing  cleansers  to  the  apical 
foramen  usually  result  in  pricking  the  pericementum  at  the  perforation 
and  a  flow  of  blood  follows,  filling  the  canal.  The  cleansers  are  bent  so 
that  in  passing  them  to  the  apex  they  press  against  the  wall  opposite 
the  perforation ;  the  apical  portion  of  the  canal  may  be  detected  and 
cleansed  after  this  manner  in  some  cases.  The  temporary  dressings  in 
these  canals  should  be  one  of  the  antiseptic  oils,  cassia  or  myrtol.  A 
dressing  of  oil  on  cotton  should  remain  a  week,  and  no  attempt  at  canal 
filling  be  made  until  all  evidences  of  pericemental  disturbance  vanish. 
A  fine  cone  of  gutta-percha  is  passed,  when  practicable,  into  the  canal 
beyond  the  perforation  ;  the  remainder  of  the  canal  is  filled  with  chloro- 
percha,  and  the  silk  points  covered  with  gutta-percha.  The  canal  at 
the  proximal  side  of  the  perforation  is  filled  with  the  solution,  by  means 
of  the  long  dressing  pliers,  the  gutta-percha-covered  silk  being  carried 
gently  in  position  while  the  general  mass  is  fluid,  Balsamo  del  deserto 
should  apply  well  in  these  cases.  The  canal  is  filled,  or  partially  filled, 
with  the  material,  and  a  large  gutta-percha  point  introduced. 


CHAPTER    XIX. 

PYORRHEA  ALVEOLARIS. 

By  C.  N.  Peirce,  D.  D.  S. 


Definition. — "  Pyorrhea  alveolaris  "  is  a  generic  term  which,  strictly 
defined,  means  a  flowing  of  pus  from  an  alveoUis.  It  describes  merely 
a  symptom  which  may  be  and  usually  is  attendant  upon  a  variety  of 
disorders.  The  term  is  applied  in  clinical  dentistry  to  a  complexus  of 
pathological  conditions  which  more  or  less  clearly  indicate  a  specific 
disease. 

History. — That  pyorrhea  alveolaris  is  not  a  recent  disease,  or  one 
due  to  modern  constitutional  states  alone,  is  rendered  evident  from  the 
examination  of  the  skulls  of  ancient  as  well  as  modern  races.  The 
alveolar  processes  of  many  crania  widely  separated  both  in  time  and  in 
locality  exhibit  marked  impairment  of  structure  which  bears  the  closest 
resemblance  to  that  presented  by  processes  which  were  known  to  have 
been  the  result  of  pyorrhea  during  life. 

Recorded  observations  of  this  disorder  date  at  least  as  far  back  as 
.1746,  when  ]\I.  A.  Fauchard  described  its  essential  clinical  features,  but 
failed  to  designate  it  by  any  specific  term.  Following  this,  communica- 
tions describing  the  disease  were  published  by  Jourdain  in  1778,  by 
Toirac  in  1823,  and  by  M.  Marechal  de  Calvi  in  1860,  in  which  it  was 
described  as  a  "  conjoint  suppuration  of  the  gums  and  alveoli,"  pyorrhea 
inter-akeoh-dentaire,  and  gingivitis  exjmlsiva  respectively. 

The  most  important  contribution  to  the  knowledge  of  the  nature  of 
the  disease  which  had  up  to  that  date  been  made  was  by  Dr.  E.  INIagitot 
in  1867.  In  his  paper  he  states  that  the  disease  is  characterized  by  a 
slow  but  progressive  inflammation  destructive  of  the  periosteal  mem- 
brane and  cementum,  proceeding  from  the  neck  to  the  apex  of  the  root 
and  involving  the  loss  of  the  teeth.  From  the  exact  seat  of  the  lesion 
he  designated  the  disease  osfeo-pcriosfiti  aJveoIn-dentaire.  Soon  after  the 
appearance  of  the  periosteal  inflammation,  it  became  complicated  with 
diseases  of  the  gums  and  the  osseous  walls  of  the  alveolus,  though 
these  are  never  primarily  the  seat  of  inflammation.  Magitot  regarded 
the  causes  of  the  inflammation  as  very  complex,  and  to  be  sought  for 
not  in  the  teeth  and  gums,  but  in  certain  conditions  of  the  general  nutri- 

505 


506  PYORRHEA    ALVEOLA RIS. 

tion.  The  gouty  and  rlicumatie  pn^scntcd  tlie  disease  most  frecjiiently, 
though  its  presence  in  those  suti'eriug  from  diabetes  and  albuminuria 
was  extremely  common.  The  deposition  of  tartar  on  the  roots  of  the 
teeth,  which  might  at  first  glance  be  regarded  as  playing  an  imj)ortant 
l)art  in  the  causation  of  the  disease,  Magitot  considered  as  accidental 
and  not  to  be  looked  upon  as  a  causative  agent.  With  reference  to  the 
efficacy  of  any  treatment,  however,  he  advised  the  removal  of  the  tartar 
as  an  indispensable  preliminary.  The  points  of  diagnosis  differentiating 
between  this  condition  and  the  former,  that  of  gingivitis,  however 
severe,  were  also  clearly  recognized  and  noted. 

Following  Magitot's  able  paper  was  one  by  Serran  in  1880,  in  which 
the  author  took  exception  to  certain  of  Magitot's  views,  as  well  as  to  the 
term  by  which  the  latter  proposed  to  designate  the  disease.  He  recog- 
nized, however,  that  the  disease  was  most  common  in  middle  life  and 
occurred  principally  among  the  gouty,  the  diabetic,  and  the  albuminuric. 
He  believed  that  the  primary  manifestation  was  a  local  congestion  of 
the  gums,  followed  by  an  exudation  into  the  peridental  membrane  which 
destroyed  its  vitality  and  led  to  the  formation  of  pus  and  all  the  other 
symptoms  and  pathological  conditions  characteristic  of  the  disease.  A 
commission  composed  of  MM.  Depres,  Delens,  and  Magitot  was  ap- 
pointed by  the  Societe  de  Chirurgie  to  consider  the  statements  of  Dr. 
Serran.  In  this  report'  they  denied  the  f/inf/ival  origin  of  the  dis- 
ease, and  stated  their  belief  that  the  periosteal  membrane  and  the 
cementum  were  the  primary  anatomical  seat  of  the  lesion  ;  that  the 
succession  of  morbid  phenomena  completely  precluded  the  idea  of  an 
initial  gingivitis  ;  that  the  disease  begins  without  any  trace  of  conges- 
tion of  the  gums  ;  that  after  its  formation  the  pus  burrows  toward  the 
gingival  border,  which  it  detaches — without,  however,  for  a  time  de- 
stroying its  normal  aspect ;  that  only  after  considerable  augmentation 
of  the  flow  of  pus  and  the  loosening  of  the  teeth  do  the  gums  become 
implicated  ;  that  the  disease  has  nothing  in  common  with  the  hypothesis 
of  a  gingival  malady,  and  that  it  is  most  frequently  a  manifestation  of 
a  general  state,  or  a  diathesis. 

These  were  the  views  entertained  and  published  by  French  surgeons 
on  the  nature  of  "  pyorrhea  alveolaris "  about  the  period  when  the 
disease  began  to  receive  consideration  from  American  dentists.  Though 
pyorrhea  alveolaris  had  long  been  recognized  in  the  United  States  and 
various  observations  regarding  its  pathology  and  treatment  had  been 
published,  it  was  not  until  Dr.  John  W.  Riggs,  in  October,  1875,  read 
a  paper  before  the  American  Academy  of  Dental  Surgery,  entitled 
"  Suppurative  Inflammation  of  the  Gums  and  Absorption  of  the  Gums 
and  Alveolar  Processes,"  that  the  disease  began  to  attract  the  attention 
^  Bulletins  et  Memoires  de  la  Societe  de  Chirurgie,  tome  vi.  p.  411. 


HISTORY.  507 

its  gravity  merited.  Xotwithstanding  the  views  entertained  by  ]\Iagit6t 
and  others  regarding  the  constitutional  character  of  the  disease,  Dr. 
Riggs  in  his  communication  ^  emphatically  denied  that  the  disease  is  an 
affection  of  the  bone  or  of  the  gums,  or  that  it  is  hereditary  or  constitu- 
tional, but,  on  the  contrary,  that  it  is  the  roughened  teeth  themselves, 
in  consequence  of  the  accretions  from  whatever  source  derived,  which 
are  the  exciting  cause  of  the  InHanimation  ;  that  it  is  purely  local  in 
origin,  the  result  of  concretions  near  and  under  the  free  margins  of  the 
gums,  the  removal  of  which  even  in  the  third  stage  is  followed  by  cure. 

In  1877  Dr.  F.  H.  Rehwinkel "  entered  his  protest  against  the 
theory  of  the  local  origin  of  the  disease,  and  endeavored  to  prove  that 
it  not  only  may  but  does  exist  independently  of  foreign  deposit  and 
must  depend  on  other  than  merely  local  causes,  and  that  it  is  an 
hereditary  and  constitutional  disease. 

Dr.  L.  C  Ingersoll,  in  1881,  published  a  paper  entitled  ''San- 
guinary Calculus,"  ^  in  which  it  was  stated  that  the  persistent  flow  and 
discharge  of  pus  along  the  side  of  the  tooth  was  caused  by  an  inflamma- 
tion and  ulceration  at  or  near  the  apex  of  the  root ;  as  a  result  of  which 
molecular  death  the  liquor  sanguinis  escaped  from  the  bloodvessels  into 
the  surrounding  tissues  and  became  disorganized,  the  lime  salts  crystal- 
lized on  the  surface  of  the  roots,  and  formed  the  deposit  which  from  its 
origin  he  designated  "  sanguinary  calculus."  This  deposition  he  re- 
garded as  entirely  distinct  from  salivary  calculus,  and  as  derived  from 
the  blood — the  result  of  inflammatory  action  and  not  its  cause.  In 
other  words,  he  held  that  pyorrhea  is  a  local  disease  but  beginning 
centrally ;  that  is,  at  or  near  the  apex  of  the  root. 

In  1882,  Dr.  A.  AVitzell  read  a  paper  before  the  German  Society  of 
Dentists,*  in  which  it  was  asserted  that  the  primary  pathological  change 
was  an  inflammation  and  caries  of  the  alveolar  border  followed  by  a 
deposit  just  beneath  the  free  margins  of  the  gums,  which  became  re- 
tracted and  reverted.  The  entrance  of  micro-organisms  into  this  carious 
region  developed  pus  Avhich  became  more  or  less  infectious.  In  conse- 
quence he  termed  the  disease  "  infectious  alveolitis."  He  regarded  the 
disease  as  a  primary  local  alveolitis,  having  no  constitutional  relations 
whatever,  a  molecular  necrosis  of  the  alveoli  or  caries  of  the  dental 
sockets  produced  by  septic  irritation  of  the  medulla  of  the  bone. 

In  188G,  Dr.  G.  Y.  Black  prepared  for  publication  probably  the 
most  exhaustive  paper  in  print  in  the  United  States,  wherein  pyorrhea 

*  Pennsylvania  Journal  of  Dental  Science,  vol.  iii.  p.  99. 

■■^  Report  of  the  Committee  on  Patholoarv  and  Surgery,  Trans.  American  Dental  Asso- 
ciation, 1877,  p.  96. 

^  Ohio  State  Journal  of  Dental  Science,  vol.  i.  p.  189. 

*  Vierteljahresschriflfiir  Zaimheilkunde,  1882;  British  Journal  of  Dental  Science,  vol.  xxv. 
p.  150. 


508  PYORRHEA  ALVEOLARIS. 

nlveohiris  is  trentotl  as  a  local  disturbance.^  Calcic  inflaimiiation  and 
phagt'donic  [XM'iccnicntitis  are  the  terms  he  employs  to  indicate  its  cha- 
racter. Thouoh  he  believes  it  to  be  wholly  local,  he  thinks  a  serumal 
or  sanguinary  deposit  may  be  closely  allied  Avith  its  origin.  He  de- 
scribes it  as  a  destructive  inflammation  of  the  pericemental  m(>mbrane, 
distinct  from  other  iirtlammations  of  this  tissue  though  having  many 
features  in  common  with  them.  The  disease,  he  estimates,  is  essentially 
one  of  the  peridental  membrane  rather  than  of  the  alveolus,  though  the 
destruction  of  these  two  structures  is  so  nearly  synchronous  that  it  is 
difficult  to  say  which  has  gone  first. 

In  1886,  Dr.  W.  J.  Reese  read  a  paper  before  the  Louisiana  State 
Dental  Association  on  "  Uremia  and  Its  Effect  on  the  Teeth,"  ^  in  which 
the  chemical,  physiological,  and  pathological  relations  of  uric  acid  to  the 
general  nutrition  were  discussed.  In  this  communication  Dr.  Reese  ex- 
pressed the  opinion  that  the  inflammation  of  the  pericemental  membrane 
followed  by  suppuration  and  disorganization  when  in  contact  with  the 
secretions  of  the  mouth,  is  caused  by  the  deposition  of  uric  acid  derived 
from  the  blood ;  that  the  disease  should  be  termed  "  phagedena  peri- 
cementi ; "  that  "  pyorrhea  alveolaris  "  is  a  misnomer.  He  also  stated 
that  while  the  tophus  on  the  roots  of  the  teeth  is  the  usual  con- 
comitant of  uric  acid,  it  is  not  necessarily  so,  but  that  absorption  of 
the  pericemental  membrane  may  take  place  without  any  deposit. 
Though  a  local  treatment  was  advocated,  he  stated  that  without  sys- 
temic or  constitutional  treatment  the  return  of  the  trouble  may  be 
expected. 

Dr.  John  S.  Marshall,  in  1891,  expressed  his  conviction  that  pyor- 
rhea has  a  constitutional  origin  and  is  closely  allied  to  the  rheumatic 
or  gouty  diathesis  ;  *'  that  the  deposition  of  the  concretions  upon  the 
roots  of  the  teeth  in  those  localities  not  easily  reached  by  the  saliva,  or 
in  which  the  presence  of  the  saliva  would  be  an  impossibility,  is  due 
to  the  causes  which  produce  the  chalky  formations  found  in  the  joints 
and  fibrous  tissues  of  gouty  and  rheumatic  individuals."  ^ 

The  writer,  in  a  series  of  papers  published  during  1892-94-95,^  pre- 
sented a  number  of  clinical  and  pathological  facts  which  in  their  totality 
it  was  believed  established  a  kinship  between  pyorrhea  alveolaris  or 
hematogenic  calcic  pericementitis  and  the  constitutional  state  familiarly 
known  as  the  gouty  or  uric  acid  diathesis. 

Recent  literature  by  American  writers  has  dealt  largely  with  the 

1  "  Diseases  of  the  Peridental  Membrane  having  tlieir  Beginning  at  the  Margin  of 
the  Gum,"  American  System  of  Dentistry,  vol.  i.  p.  953. 

^  Dental  Cosmos,  vol.  xxv.  p.  550. 

•^  "  The  Rheumatic  and  Gouty  Diathesis,  with  its  Manifestations  in  the  Peridental 
Membrane,"   Trans.  American  Medical  Association,  1891. 

*  International  Dental  Journal,  vols,  xiii.,  xv.  and  xvi. 


TERMINOLOGY.  509 

problem  of  the  etiology  of  the  di^sea^^e  in  question  and  has  been  princi- 
pally concerned  in  determining  whether  it  is  of  constitutional  origin  or 
of  local  origin,  or  of  both.  Of  the  more  important  recent  writings  on 
the  subject  may  be  mentioned  those  of  Drs.  E.  T.  Darby,  H.  H.  Bur- 
chard,  G.  V.  Black,  M.  L.  lihein,  E.  L\  Kirk,  James  Truman,  Junius 
E.  Cravens,  Louis   Jack,  K.  K.  Andrews,  and  R.  Ottolengui. 

Terminology. — No  disease  in  the  whole  domain  of  surgery  has 
received  so  many  and  such  diverse  names  as  the  one  under  consideration. 
Each  succeeding  title  was  an  attempt  at  the  production  of  a  comprehen- 
sive descriptive  designation  of  the  disease,  but  when  it  is  recognized 
that  the  essential  nature  of  the  pathological  processes  involved  is,  even 
now,  not  fully  made  out,  it  is  evident  that  the  many  names  simply 
represent  as  many  diverse  views  and  can  therefore  have  no  permanency, 
nor  do  they,  indeed,  deserve  any. 

The  following  is  a  fairly  complete  list  of  the  synonyms  of  the  dis- 
order :  Suppuration  eonjointe  ;  Pyorrhea  inter-alveolo-dentaire  ;  Gingi- 
vitis expulsiva  ;  Osteo-periostiti-alveolo-dentaire  ;  Pyorrhea  alveolo  ; 
Cemento-periostitis  ;  Infectioso-alveolitis  ;  Pyorrhea  alveolaris  ;  Calcic 
inflammation  ;  Phagedenic  pericementitis ;  Riggs'  disease  ;  Hemato- 
genic calcic  pericementitis  ;  Blennorrhea  alveolaris  ;  Gouty  pericemen- 
titis. 

Examining  the  foregoing  list,  from  the  pathological  point  of  view,  it 
will  be  observed  that  there  is  a  wide  divergence  of  opinion  as  to  the 
conditions  Avhicli  should  be  included  under  the  generic  title  of  pyorrhea 
alveolaris. 

As  the  term  is  now  understood,  pyorrhea  alveolaris  includes  all  of 
those  cases  of  morbid  action  characterized  by  the  following  features  : 
A  molecular  necrosis  of  the  retentive  structures  of  the  teeth  (their  liga- 
ment, the  pericementum),  an  atrophy  of  the  alveolar  walls,  together 
with  a  chronic  hyperemia  of  the  gum  tissue  which  leads  to  limited 
hypertropliy.  After  a  variable  period  the  teetli  drop  out,  and  the  mor- 
bid action  ceases  with  their  loss.  An  examination  of  the  roots  of  the 
teeth  before  or  after  their  exfoliation  usually  exhibits  deposits  of  cal- 
culi upon  their  surfaces.  The  disease  is  generally  though  not  always 
attended  by  a  flow^  of  pus  from  the  alveoli. 

Clinically  the  cases  in  which  these  phenomena  are  observed  may  be 
divided  into  two  classes  :  First,  those  in  which  the  disease  process  ap- 
pears to  begin  at  the  gum  margin.  The  second  class,  those  in  connec- 
tion with  which  there  is  much  controversy,  begin  at  some  portion  of 
the  alveolus  between  the  unbroken  and  apparently  healthy  gum  margin 
and  the  apex  of  the  root,  the  l)ulp  of  the  tooth  being  alive.  These  two 
conditions  are  so  clearly  ditferentiated  from  one  another  that  each  re- 
quires a  separate  description.    Between  these  two  classes,  but  intimately 


510  PYORRHEA  ALVEOLARIS. 

associated  with  tlie  latter,  are  to  be  included  the  cases  described  ])y  Dr. 
G.  \ .  Black '  as  '*  phagedenic  pericementitis." 

Class  I.   Pyorrhea  Alveolaris  beginning  at  the  Gum 
Margin  (Ptyalogenic  Calcic  Pericementitis). 

The  first  class — those  cases  beginning  not  at,  but  immediately  be- 
neath the  gum  margin — are  perhaps  the  most  common,  are  by  some 
erroneously  supposed  to  be  the  only  type  of  cases,  and  will  require 
description  first,  as  their  causes,  progress,  prognosis,  and  treatment 
differ  radically  from  those  of  the  second  class. 

Causes  of  Class  I. — As  in  any  disease,  the  causes  of  pyorrhea 
alveolaris  grouped  as  Class  I.  may  be  divided  into  predisposing  and 
exciting.  The  predisposing  causes  may  all  be  included  under  the  head 
of  disorders  causing  a  subacute  inflammation  of  the  gingivae.  General 
catarrhal  conditions;  small  but  irritating  deposits  upon  the  necks  of  the 
teeth,  as  the  accumulations  upon  the  teeth  of  smokers ;  fermenting 
deposits  of  food  ;  spirit-drinkers'  stomatitis,  mouth-breathers'  gingivitis  ; 
overcrowding  of  the  teeth,  mal-occlusion,  and  non-occlusion.  The  pre- 
disposing causes  may  also  frequently  be  the  exciting  causes.  The  excit- 
ing causes  proper  are,  however,  subgingival  scaly  deposits  of  calculi. 

Clinical  History. — In  the  mouth  of  a  patient  of  one  of  the  above- 
mentioned  classes  there  will  be  noted  at  some  period  a  gingivitis — a 
swelling  of  the  gum  which  does  not  extend  far  from  their  margins. 
It  is  noteworthy  that  in  these  cases,  as  in  the  succeeding  class,  it  is 
usual  to  find  the  disease  attack  teeth  which  are  comparatively  or  quite 
exempt  from  the  inroads  of  caries.  Soon  after  the  incipiency  of  the 
disease  there  may  be  squeezed  from  beneath  the  gum  margins  a  detritus 
of  food  debris  and  inspissated  mucus.  At  a  later  stage  a  sharp  scaler 
passed  beneath  the  gum  margin  may  detach  a  flat  greenish  or  black  de- 
posit of  calculus.  Later,  the  gingivfe  are  seen  to  become  swollen  and  are 
gradually  detached  from  the  neck  of  the  tooth,  the  flattened  calculus  in- 
creases in  volume,  and  the  irritation  and  injection  of  the  gum  deepens. 
''  It  is  probable  that  these  deposits  have  their  origin  in  a  reaction  be- 
tween the  altered  mucous  secretion  of  the  gingival  glands  and  the  pro- 
ducts of  lactic  fermentation,  their  calcic  salts  being  derived  from  the 
saliva."  ^  The  detachment  of  the  gum  does  not  become  marked  until 
these  dark  scaly  deposits  have  encroached  upon  the  margins  of  the 
alveolus.  Soon  thereafter,  or  indeed  before,  evidences  of  infection  are 
observed,  from  the  fact  that  pus  may  be  pressed  from  the  pockets.  The 
disease  progresses,  the  teeth  loosen,  and  ultimately  drop  out  or  are  re- 

^  American  Si/Mem  of  Dentistry,  vol.  i. 

^  H.  H.  Bnrchard,  Dental  Cosmos,  October,  1895. 


PATHOLOGY  AND  MORBID  ANATOMY 


511 


Fig.  474. 


moved  with  the  fijigers,  the  injected  gum  remaining  as  a  flabby  mass 
and  all  evidences  of  dental  disease  ceasing  with  the  loss  of  the  teeth. 
The  process  may  involve  one,  two,  or  more  teeth  and  in  some  cases  an 
entire  denture.  The  origin  of  these  deposits  as  well  as  those  of  ordi- 
narv  calculi  are  so  clearly  traceable  to  the  saliva  that  the  writer  has 
suggested  for  the  conditions  caused  by  them  the  name  of  ptyalogenic 
calcic  pericementitis. 

Pathology  and  Morbid  Anatomy. — The  apjiended  figure,  semi- 
diagrammatic,  will  illustrate  clearly  the  nature  of  the  disease  process 
(Fig.  474).  It  represents  a  longitudinal  section  through  a  tooth 
and  its  alveolus,  with  the  vascular  supply  to  the  tissues.  The  peri- 
cementum and  alveolar  walls  for  some  distance  from  the  apex  of 
the  root  are  in  a  healthy  condition.  At  the  neck  of  the  tooth  are 
seen  two  deposits  of  calculi  (a,  a).  The  overlying  gum  (h,  b)  is 
seen  to  be  swollen  and  tumid  at  its  edges.  Immediately  below  the 
calculus,  where  it  encroaches  upon  the  pericementum,  the  latter  tissue 
and  also  a  portion  of  the  alveolar  periosteum  is  seen  to  have  under- 
gone necrotic  changes  (d).  The  portion  of  alveolar  wall  uncovered 
by  periosteum  is  in  process  of  dissolution.  In  the  pocket  beneath  the 
calculus  a  collection  of  pus  is  seen  (c,  c),  so  that  the  tissues  beyond 
the  calculus  are  involved  in  suppura- 
tive degeneration,  which  may  be  slow 
or  rapid  in  its  progress. 

The  diagnosis  is  by  sight  and  touch 
and  not  infrecpiently  by  odor,  as  par- 
ticularly in  unhygienic  mouths  an  offen- 
sive odor  attends  the  progress  of  the 
disease.  The  gums  are  tumid ;  from 
about  the  necks  of  the  teeth  pus  may 
be  pressed,  and  touch  demonstrates  the 
presence  of  flat,  dark,  and  firmly  ad- 
herent scaly  calculi. 

The  prognosis  is  favorable  at  even 
advanced  stages,  provided  certain  con- 
ditions may  be  obtained,  viz.  a  removal 
or  correction  of  the  predisposing  causes 
and  a  perfect  removal  of  the  exciting 
causes. 

Treatment. — The  treatment  is  based 
purely  upon  the  existing  conditions,  with  two  main  objects  in  view. 
The  first  is  to  remove  every  source  of  irritation  ;  the  second,  to  procure 
surgical  rest  until  there  is  a  return  of  the  surrounding  tissues  to  a 
normal  condition. 


— d 


Ptyalogenic  calcic  pericementitis 
(Burchard). 


512 


PYORRHEA   ALVEOLARIS. 


475. 


Cushing's  scalers. 


As  a  general  rule  the  first  step  of  the  operation  consists  in  a  careful 
and  thorough  scaling  of  the  teeth.  It  is  essential  that  the  use  of  bulky- 
sealers  be  avoided — first,    for  the  reason    that   they  rarely  reach   the 

deepest  portions  of  the  deposits ; 
second,  that  if  they  do,  they  cause 
more  or  less  laceration  of  the  gum, 
which  should  be  kept  as  free  from 
injury  as  possible.  The  instru- 
ments employed  for  this  purpose 
by  a  majority  of  operators  are  the 
set  known  as  Cushing's  scalers 
(Fig.  475).  Their  mode  of  appli- 
cation and  their  position  relative 
to  the  root  are  shown  in  Figs.  476, 
477.  No  instrument  with  a  draw 
cut  can  remove  these  deposits  with  the  same  thoroughness  as 
one  operated  with  a  push  cut.  With  proper  guarding  it  is 
improbable  that  these  instruments  should  do  harm  to  the 
vital  parts  beyond  the  calculus.  Great  care  should  be  exer- 
cised in  the  use  of  pushing  instruments  to  avoid  forcing  the 
dislodged  particles  into  the  deeper  tissues.  The  scaling  is  a 
tedious  operation,  but  one  which  should  be  persisted  in  until 
the  root  of  the  affected  tooth  is  absolutely  smooth.  The  scal- 
ing is  alternated  with  a  washing  out  of  the  pockets  with  3 
l^er  cent,  pyrozone  or  hydrogen  dioxid,  which  washes  out  the 
detached  particles  of  calculus  and  disinfects  the  parts.  "  When 
the  gums  are  tumid  and  interfere  notably  with  the  scaling  pro- 
cess, applications  are  made  of  a  solution  of  trichloracetic  acid 
1:10  upon  cotton  tents ;  this  checks  oozing,  shrinks  the  gum, 
giving  a  better  view  of  the  parts,  and  tends  to  soften  the  de- 
posits." ^  "  It  not  infrequently  happens  that  the  teeth  have 
suffered  such  extensive  loss  of  their  retaining  structures  that 
the  operation  of  scaling  tends  to  still  further  loosen  them.  In 
these  cases  the  correction  of  mal-occlusion  and  splinting  the 
teeth  should  be  attended  to  before  proceeding  farther  with  the 
operation.  The  teeth  should  be  ligatured  to  their  fellows, 
and  the  excessive  occlusion  corrected  by  grinding  away  the 
points  of  contact  with  corundum  wheels  sufficiently  to  relieve 
the  teeth  of  strain  and  to  permit  the  fixing  of  a  metallic  splint 
by  means  of  which  the  teeth  may  be  held  firmly,  during  and  subsequent 
to  the  scaling  operation."  ^ 

Splints  for  these  cases  are  usually  swaged  metallic  caps  made  of 

1  E.  C.  Kirk.  ^  H.  H.  Burchard,  International  Dental  Journal,  August  1895. 


PATHOLOGY  AXD  MORBID  ASATOMY. 


513 


No.  31  metal,  gold  or  silver,  which  are  cemented  to  the  teeth  (Fig. 
478).  ^yhen  the  teeth  have  suitable  forms,  a  succession  of  rings  sol- 
dered together  may  be  employed  ;  in  other  cases  the  teeth  are  lashed 
together  by  means  of  fine  gold  Avire.  For  tem^jorary  use  No.  31  or  32 
annealed  brass  wire  may  be  used,  and  when  left  in  situ  for  weeks  or 
months  it  exerts  no  deleterious  effect.     In  fact,  it  appears  to  possess 

Fio.   476. 


Showing  the  m.anner  of  liolding  an  instrument  for  detaching  calcareous  deposits  when  using  the 
pushing  motion.  The  third  finger  rests  on  the  edges  of  the  teeth,  allowing  freedom  of  the 
hand  to  make  rapid  and  effectual  movements  in  dislodging  the  calculi. 


antiseptic  properties  similar  to  those  attributed  to  copper  amalgam 
when  used  as  a  filling  material.  Or,  if  frequently  renewed,  floss  silk 
may  be  used.  Devices  for  this  purjjose  are  as  numerous  as  designs 
for  bridge  work. 

Each  root  is  to  be  perfectly  scaled  before  proceeding  to  a  second 
tooth.  At  the  completion  of  the  scaling  the  pockets  are  freely  syringed 
out  with  pyrozone  3  per  cent.,  and  an  application  of  an  a.stringent  made: 
a    10    per  cent,  solution  of  zinc  chlorid,  20  per  cent,  solution   of  zinc 

3.3 


514 


ry  ORRIIEA    A  L  VEOLA  RIS. 


iodic],  or  tr.  iodin.  U.  S.  P.  diluted  ono-lialf  with  alcohol.     Prepara- 
tions of  aristol  and  the  officinal  tincture  of  iodin  are  also  used,  all  of 

which    subserve    the    desired    end,    to 
^"^'  sterilize    the    parts    and    to    constringe 

the    dilated    vessels    of  the  gum.     An 
antiseptic  and    astringent  mouth-wash 

Fi(i.  47S. 


is  prescribed  which  the  patient  is  to 
use  several  times  daily.  The  follow- 
ing preparation  applied  on  a  small  roll 
or  tuft  of  cotton  wool  or  by  means  of 
a  soft  toothbrush  admirably  meets  the  conditions  : 


Showing  the  application  of  a  tliin  flat 
instrument  to  the  hibial  and  approxi- 
mal  surfaces  of  an  upper  bicuspid 
(pushing  motion). 


II.  Zinci  chlorid.,  cryst., 
Aquae  mentha?  pip., 
S.  Apply  locally  to  the  gums. 


fsiv.— M. 


As  early  in  the  treatment  as  possible  a  thorough  examination  should 
be  made  with  a  delicate  exploring  instrument,  so  that  any  calculi  which 
may  be  detected  may  be  removed. 

A  method  of  treatment  w  hich  has  given  much  satisfaction  to  the 
writer  is  as  follows  :  First  thoroughly  cleanse  the  mouth  and  each 
particular  pocket  with  hydrogen  peroxid,  electrozone,  or  some  other 
equally  efficient  antiseptic.  Then  with  a  blunt  but  flexi1)le  l)roach, 
gold  or  steel,  let  each  pocket  from  which  pus  has  been  issuing  be  very 
carefully  saturated  with  trichloracetic  acid  ;  this  is  repeated  each  visit 
if  pus  continues  to  flow.  Following  this,  the  pockets  and  gingival 
borders  or  margins  are  thoroughly  treated  with  tincture  of  iodin,  fol- 
lowed with  solution  of  hydronaphthol  and  alcohol.  If  the  gingivee, 
however,  should  be  tumefied,  an  application  of  carbolic  acid  will  prove 
advantageous  : 

^.  Hydronaphthol,  Sij  ; 

Alcohol,  %\v. 

This  must  be  used  with  caution,  for  it  is  of  sufficient  strength  to  give 
the  patient  much  discomfort  if  brought  in  contact  with  lips  and  tongue. 
The  frequency  of  the  visits  and  applications  must  depend  upon  the  viru- 


GOUTY  PERICEMENTITIS.  515 

lenoe  of  the  disease.     A  wash  for  the  patient's  daily  use  made  from  the 
following  formula  will  be  of  great  service  : 

I^.  Hydronaphthol,  gr.  x  ; 

Glycerol,  Sj ; 

Alcohol,  3ij  ; 

Aquse  dest.,  oij. 

The   use  of  hydronajihthol   in   pyorrhea  alveolaris    was   suggested  by 
Prof.  James  Truman. 

The  loss  of  alveolar  walls  is  permanent ;  the  utmost  the  operator 
can  hope  in  extreme  cases  is  a  reorganization  of  the  tissues  which 
have  been  softened  as  a  consequence  of  the  inflammatory  action. 

Class  II.   Pyorrhea  Alveolaris  of  Constitutional  Origin — 
Gouty  Pericementitis. 

The  second  class  of  pyorrhea  cases — those  in  which  local  therapeusis 
has  not  been  attended  with  permanent  good  results — are  usually  chronic, 
extending  over  a  variable  period  of  time,  owing  to  the  fact  that  they  are 
but  the  local  expression  of  constitutional  states.  Of  these  many  forms  of 
pyorrhea,  one  is  particularly  persistent,  terminating  only,  unless  prop- 
erly treated,  with  the  exfoliation  of  the  affected  teeth.  This  particular 
form,  which  has  been  the  subject  of  much  discussion  during  the  past 
twenty-five  years,  the  writer  believes  to  have  been  shown  to  be  but  a 
local  expression  of  the  gouty  diathesis  and  directly  dependent  on  the 
deposition  of  the  uric  acid,  urates,  and  calcium  salts  in  the  pericemental 
membrane  ;  though  it  is  probable  that  allied  and  closely  related  com- 
pounds, such  as  the  xanthin  or  alloxuric  bases  (xanthin,  guanin,  and  aden- 
in),  may  also  be  present  in  small  quantities.  Indeed,  as  the  gouty  diathe- 
sis is  largely  dependent  on  a  faulty  metabolism  of  proteid  compounds  and 
an  imperfect  elimination  of  nitrogen-holding  derivatives,  it  is  quite  pos- 
sible, though  not  proved,  that  any  or  all  derivatives  may  be  present  in 
any  pathological  deposition.  Inasmuch,  however,  as  the  amounts  of 
these  compounds  are  small,  uric  acid  and  uratic  salts  must  be  regarded 
as  the  chief  of  the  specific  irritants.  As  the  origin  of  the  salts  is  from 
the  blood,  the  w^riter  suggested  the  term  hematoc/enie  calcic  j^ericementitis. 
Subsequently  Dr.  E.  T.  Darby  suggested  the  happily  applicable  term 
gouty  p  ericement  it  is. 

Clinical  History. — It  is  noted  that  many  patients  who  have  mag- 
nificent dentures  almost  exempt  from  caries,  at  a  period  about  middle 
life  begin  to  have  a  loosening  of  the  teeth  which  if  unchecked  leads 
to  the  loss  of  the  entire  denture.  The  disease  may  be  observed  at 
anv  stage  from  a  slight  loosening  to  impending  exfoliation.  An  exam- 
ination of  many  cases  will  show  that  although  they  i)resent  apparently 


516  PYORRHEA   ALVEOLARIS. 

diverse  foiiditions,  yet  beneath  these  differenees  there  is  a  strikiiiii;  uni- 
formity, partieuhirly  as  to  the  family  liistory  of  such  patients. 

A  eomph'te  and  accurate  study  of  the  succession  of  symptoms  which 
a  ty])ieal  case  of  g:outy  pericementitis  presents  from  its  inception  to  its 
termination  is  rendered  difficult,  owing  to  the  lack  of  extended  observa- 
tion of  the  disease  throuo^hout  the  entire  period  of  its  evolution  and  dis- 
solution. This  is  especially  true  of  this  disease  in  its  earlier  stages. 
Nevertheless  from  an  attentive  study  of  a  large  number  of  individual 
cases  in  various  stages  of  develo^mient  it  is  believed  that  a  fairly  cor- 
rect picture  can  be  deduced. 

First  as  to  the  teeth  themselves ;  as  stated,  they  are  almost  exempt 
from  recent  caries.  The  teeth  frequently  exhibit  a  tendency  to  me- 
chanical abrasion  upon  their  cutting  edges  or  labial  surfaces.  If  the 
patient  be  of  a  sanguine  temperament,  or  this  temperament  combined 
with  the  bilious,  the  tendency  to  erosion  is  much  more  pronounced. 
It  must  be  appreciated  that  this  destruction  of  tooth  tissue  has  nothing 
in  common  with  ordinary  dental  decay  or  with  the  results  of  friction 
in  mastication. 

In  nearly  all  cases,  should  excavation  of  cavities  in  the  teeth  become 
necessary,  or  sections  of  lost  teeth  be  examined,  it  will  be  found  that  the 
pulp  has  receded,  i.  e.  has  suffered  a  continued  stimulation  of  its  func- 
tional activity  to  the  extent  almost  of  obliteration. 

The  patient  may  consult  the  operator  as  to  the  causes  of  repeated 
attacks  of  dental  neuralgia,  or  the  reason  of  consultation  may  be  the 
alteration  of  position  of  one  or  more  teeth.  An  examination  of  the 
organs,  however,  reveals  no  evident  cause  for  either  the  neuralgia  or  the 
displacement. 

If  the  malposed  tooth  be  kept  under  observation  it  will  usually  bo 
seen  to  become  elevated,  loosen,  and  finally  drop  out.  Other  teeth 
become  affected  in  a  similar  manner.  Dr.  Burchard  has  classified  the 
course  of  pyorrhea  as  in  three  stages,  as  follows :  "  First,  tooth  indura- 
tion ;  second,  erosion  or  chemical  solution  of  the  crowns  of  the  teeth  ; 
third,  a  loss  of  the  retaining  structures  of  the  teeth.  Pathologically 
stated,  there  is  first  a  stimulative  stage;  second,  an  irritative,  charac- 
terized by  altered  secretion  (erosion) ;  third,  the  necrotic." 

The  altered  secretion  pertains  to  the  labial  glands  largely,  and  the 
necrosis  to  the  pericemental  membrane  and  the  apical  end  of  the  root 
or  that  portion  which  has  been  denuded  of  the  membrane  ;  while  the 
alveolar  process  never,  in  the  writer's  judgment,  undergoes  any  change 
except  that  of  absorption  and  atrophy. 

By  far  the  greater  number  of  cases  present  themselves  when  the 
disease  has  made  marked  advance  about  one  or  several  teeth  and  their 
immediate  loss  is  threatened. 


GOUTY  PERICEMENTITIS.  517 

Assuming  that  the  gouty  diathesis  however  well  or  poorly  developed 
may  be  a  predisposing  cause,  and  the  deposition  of  some  characteristic 
specific  gouty  material  from  the  blood  into  the  pericemental  tissues  the 
immediate  or  exciting  cause,  we  have  an  explanation  for  the  irritation 
and  necrosis  of  the  alveolo-cemental  membrane,  Avhich  even  in  its  early 
stages  is  easily  recognizable.  Coexistent  with  the  ])ericemental  hyper- 
emia there  is  more  or  less  redness  and  turgescence  of  the  gums,  accom- 
panied by  a  sense  of  tenderness,  soreness,  and  in  many  cases  neuralgic 
pain,  which  latter  symptom  frequently  precedes  all  other  symptoms. 
In  individuals  already  suffering  from  pyorrhea,  the  early  irritative 
stage  of  the  disorder  may  be  frequently  observed  in  teeth  previously 
free  from  all  signs  of  the  disease.  In  nearly  all  such  instances  the  focus 
of  the  diseased  action  is  confined  almost  exclusively  to  the  region  toward 
the  apical  extremity  of  the  root  without  there  being  the  slightest  evi- 
dence of  peripheral  local  gingivitis.  Too  much  stress  cannot  be  placed 
on  this  fact,  as  it  unquestionably  marks  the  incipiency  of  the  disease  and 
is  one  of  the  early  diagnostic  symptoms. 

Somewhere  near  the  apex  of  the  root  a  distinct  swelling  occurs  simu- 
lating an  acute  apical  abscess.  The  tooth  is  sensitive  upon  percussion, 
but  less  so  than  when  affected  by  purulent  apical  pericementitis  ;  more- 
over by  isolating  the  tooth  it  is  found  to  respond  to  applications  of 
cold,  proving  that  its  pulp  is  alive.  A  bistoury  passed  into  the  swell- 
ing is  followed  by  an  escape  of  blood,  and  usually  by  a  glairy  purulent 
discharge  also,  although  not  always.  In  some  cases  a  probe  passed  into 
the  opening  may  show  an  absence  of  alveolar  process  at  that  point,  and 
by  a  roughness  reveal  the  presence  of  a  deposit  upon  the  root  of  the 
tooth. 

The  teeth  so  affected  usually  present  an  appreciable  elevation  or 
protrusion  from  their  alveoli  in  consequence  of  the  enlarged  or  thick- 
ened and  congested  pericemental  membrane.  Should  this  congestion 
be  permitted  to  continue,  the  inflammatory  stage  in  consequence  of  the 
continued  presence  of  the  irritating  deposit  will  supervene,  with  its  con- 
comitant symptoms,  heat,  pain,  swelling,  and  marked  impairment  and  in 
some  instances  total  arrest  of  the  functions  of  the  tissues  involved. 

Inflammation  once  established  will  eventuate  in  localized  suppura- 
tion with  the  abatement  of  the  acute  symptoms.  The  location  of  the 
suppurative  })rocess,  if  the  case  be  seen  and  recognized  early,  will  be 
found  in  the  large  majority  of  cases  to  be  near  the  apical  extremity  of 
the  root.  As  a  rule,  the  pus  takes  the  line  of  least  resistance  and  bur- 
rows directly  along  the  side  of  the  root  and  opens  externally  at  the 
gingival  liorder.  (Occasionally  the  line  of  least  resistance  is  toward 
the  labial  suriace,  with  the  discharge  of  pus  on  the  gum  opposite  the 
end  of   the  root,    thereby  establishing  a  fictitious  oj>ening  simulating 


518  PYORRHEA  ALVEOLARIS. 

the  condition  ohsorvcd  in  an  acute  alveolar  abscess;  these  cases,  how- 
ever, are  very  liniitecl  in  number. 

Once  established,  these  conditions  of  increased  vascularity,  tumefac- 
tion of  the  gums,  and  persistent  discharge  of  pus  may  continue  for 
months  or  years  ;  the  ra])idity  with  which  the  disease  ]ir()grcsscs  and 
the  extent  to  which  the  lesions  develop  will  be  directly  dependent  upon 
the  state  of  the  general  nutrition  and  habits  of  the  individual. 

As  a  result  of  the  continued  irritation  induced  by  the  deposit,  the 
iuHammatiou  extends,  the  disturbed  relation  between  blood  and  sur- 
rounding tissues  increases,  and  the  gums  become  flaccid,  spongy, 
altered  in  color,  and  liable  to  hemorrhagic  discharges.  Associated  with 
the  congested  and  thickened  condition  of  the  pericemental  membrane 
there  is  a  gradual  softening  and  absorption  of  the  alveolar  process,  which 
may  advance  to  such  an  extent  as  to  almost  or  in  some  cases  quite 
expose  the  root  throughout  its  entire  extent.  The  tooth  thus  freed  from 
its  retentive  structures  becomes  loose,  is  freely  movable  in  its  enlarged 
and  partially  destroyed  socket,  is  extremely  liable  to  dislodgment  by 
slight  mechanical  means,  or  if  by  care  these  are  avoided  it  will  within 
a  limited  time  be  exfoliated  in  consequence  of  the  final  and  complete 
destruction  of  all  its  retaining  structures.  With  this  final  result  the 
progress  of  the  disease  is  arrested.  The  alveolar  socket  being  freely 
opened,  the  partially  dead  and  decomposing  tissues  are  removed  and 
the  remaining  structures  gradually  restored  to  a  normally  healthy  con- 
dition by  the  usual  processes  of  repair. 

When  once  established,  pyorrhea  alveolaris  does  not  confine  itself 
to  any  one  tooth,  but  may  extend  to  adjoining  teeth  or  make  its  appear- 
ance in  rapid  succession  in  widely  separated  regions  of  the  mouth  in 
the  lower  as  well  as  the  upper  jaws  until  the  whole  denture  becomes 
involved,  with  an  eventual  exfoliation  of  all  the  teeth  and  a  complete 
resorption  of  the  alveolar  process.  When  these  exfoliated  teeth  are 
examined  there  will  be  found  at  some  point  of  the  root  surface, 
almost  always  near  the  apex,  an  incrustation  of  a  dark,  rough  cal- 
culus, or  it  may  be  several  of  them,  all  minute.  The  origin  of  the 
deposits  being  clearly  not  from  the  saliva,  which  is  the  source  of  the 
calculi  in  the  disease  described  under  the  head  of  Class  I.,  it  has  been 
called  serumal  or  sanguinary  calculus  (Ingersoll,  Black) ;  the  writer  lias 
suggested  as  the  name  of  the  disease  caused  by  such  deposits,  hemato- 
genic calcic  2^cricementitis. 

These  assumed  gouty  deposits  led  the  writer  into  an  investigation 
as  to  the  family  history  of  patients  affected  by  this  disease.  Almost 
without  exception  these  individuals  have  been  shown  to  be  either  the 
victims  of  some  phase  or  form  of  gout,  of  alleged  rheumatism  or  of 
rheumatoid  arthritis  (rheumatic  gout),  or  to  have  a  clear  family  his- 


GOUTY  PERICEMENTITIS.  519 

tory  of  one  of  these  disorders.  Careful  investigation  by  several  other 
observers  has  brought  to  light  similar  testimony,  particularly  within 
the  past  three  years  (Kirk,  Darby,  Burchard,  Jack,  and  others). 

It  had  been  noted  by  succeeding  generations  of  practitioners  that  the 
therapeutic  resources  (local)  of  dentistry  were  insufficient  to  eitlier  check 
or  cure  the  disease  condition.  All  local  means  of  treatment  having 
been  exhausted  and  shown  to  be  of  little  or  no  avail,  there  was  a  natural 
inquiry  into  the  exact  nature  of  the  predisposing  and  exciting  causes  of 
the  malady,  so  that  the  therapeusis  might  be  placed  upon  a  rational  basis. 

No  purely  local  causes  having  been  found  sufficient  to  account  for 
the  dental  condition,  all  constitutional  states  which  were  known  to 
affect  tlie  teeth  or  their  alveoli  were  examined  and  compared  with  the 
phenomena  of  the  dental  disorder.  While  it  was  and  is  found  that 
several  constitutional  conditions  do  predispose  to  pyorrhea  alveolaris,  a 
flow  of  pus  from  a  tooth  socket,  and  most  of  these  conditic^ns  may  be 
included  under  the  heading  of  diseases  of  sub-oxidation,  none  of  them 
was  found  to  cause  a  disease  having  the  precise  clinical  phenomena 
noted  in  connection  with  the  one  under  discussion.  By  a  process  of 
exclusion,  and  tiually  by  direct  clinical  and  experimental  evidence,  the 
field  of  inquiry  was  narrowed  down  to  the  conditions  which  clinical 
medicine  has  included  under  the  heading  of  the  disorders  of  the  gouty 
diathesis. 

In  order  to  clearly  comprehend  the  connection  of  the  general  condi- 
tion with  tlie  local  disease  it  is  necessary  to  examine  the  essential,  the 
intimate,  nature  of  gout  and  its  manifold  manifestations.  Much  con- 
fusion has  arisen  in  the  discussion  of  this  subject  due  to  the  lack  of 
agreement  of  observers  as  to  what  constitutes  gout,  many  apparently  as- 
suming that  gout  is  necessarily  and  inseparably  connected  with  an  acute 
attack  affecting  the  metatarso-phalangeal  articulation  (the  great  toe). 

Pathology  of  the  Constitutional  Morbid  Condition. — Pvorrhea 
alveolaris  regarded  as  a  local  manifestation  of  the  gouty  diathesis  is 
the  result  of  a  deposition  of  uratic  salts  in  the  pericemental  mem- 
brane :  these,  acting  as  a  local  irritant,  excite  a  specific  inflammation  ; 
while,  as  in  other  manifestations,  the  deposition  of  the  gouty  material 
is  determined  by  an  abnormal  condition  of  the  membrane,  a  condition 
of  impaired  vitality,  the  result  of  some  mechanical  or  other  irritation, 
which  predisposes  it  to  the  infiltration. 

As  no  special  manifestation  of  the  gouty  diathesis  can  be  intelligently 
understood  without  reference  to  its  constitutional  relations,  it  will  not  be 
out  of  place  to  briefly  consider  the  phenomena  presented  by — (1)  The 
gouty  diathesis  as  a  constitutional  malady ;  (2)  The  special  manifesta- 
tion here  under  consideration  as  a  moleculai:  necrosis  of  the  perice- 
mental membrane,  or  pyorrhea  alveolaris. 


520  PYORRIII'Li   .  1 L VI'JOLA JUS. 

The  gouti/  diafhcsis,  in  the  troneral  a('('ej)tati()ii  of  the  term,  is  a  con- 
stitutional malady  which  manifests  itself  under  a  great  variety  of  forms 
in  different  individuals.  It  is  characterized  by  an  excess  of  uric  acid 
and  its  congeners  in  the  blood,  due  either  to  increased  production, 
through  im]iaired  or  im])erfect  assimilation  of  nitrogenous  food,  or  to 
imperfect  elimination  of  the  normal  amount  of  urates  by  the  kidneys. 
In  either  event  tluM'c  is  a  disturbance  of  the  normal  relations  between 
uric  acid  production  and  the  general  nutritional  j)rocess.  The  protean 
forms  under  which  the  diathesis  manifests  itself  will  vary  in  accord- 
ance with  i\w  type  of  constitution  and  with  the  peculiarities  of  organi- 
zation and  the  degree  of  vitality  of  individual  organs  and  tissues.  The 
lesions  or  j)athological  states  observed  arc  believed  to  be  caused  by  the 
deposition  into  the  tissues,  from  the  l)lood,  of  urate  of  sodium.  This 
diathesis  is  undeniably  hereditary,  as  its  presence  is  detectable  in  one 
form  or  another  in  fully  75  per  cent,  of  all  cases  in  two  and  even  three 
generations.  The  diathesis  can  also  be  acquired  by  individuals  who  are 
subjected  to  the  causes  which  rendered  the  diathesis  hereditary.  The 
age  at  which  the  local  expressions  manifest  themselves  lies  between  the 
thirty-fifth  and  fiftieth  years,  at  a  time  when  growth  has  ceased  and  the 
food  supply  is  required  only  for  tissue  repair  and  heat  production.  It 
is  most  common  among  those  who  lead  sedentary  lives,  who  indulge  in 
an  excess  of  nitrogenous  food  beyond  the  capacity  of  the  individual  to 
perfectly  oxidize,  and  those  wdio  consume  excessive  amounts  of  fer- 
mented and  malted  beverages  and  the  heavier  wines. 

The  immediate  cause  of  all  gouty  expressions  appears  to  be  the  pres- 
ence of  urates  in  the  blood.  The  amount  normally  present  is  so  slight 
that  it  is  almost  non-detectable  by  ordinary  chemical  methods.  It  was 
shown  by  Dr.  Garrod  that  in  gouty  conditions  the  amount  was  increased 
to  as  much  as  0.175  per  1000  parts,  and  that  this  apparently  small 
quantity  was  quite  sufficient  to  act  as  the  irritating  cause  of  gout — a 
fact  corroborated  by  other  observers. 

The  various  theories  which  have  been  advocated  from  time  to  time 
in  explanation  of  this  uric  acid  increase  in  the  blood  plasma  are  unsatis- 
factory and  contradictory  ;  whether  it  is  the  result  of  imperfect  elimina- 
tion or  of  increased  production  through  excess  of  nitrogenous  foods  it 
is  difficult  to  state  positively  in  the  present  state  of  pathology.  It  is 
quite  probable  that  the  diathesis  is  a  neurosis  which  affects  simultane- 
ously the  assimilative  as  well  as  the  excretory  functions  of  the  body. 
Whatever  the  explanation  may  be  as  to  the  accumulation  of  urates, 
their  presence  in  the  blood  is  generally  admitted  to  be  the  immediate 
cause  of  any  gouty  manifestation.  Dr.  Dyce  Duckworth  states  that  "  No 
conception  of  this  malady  is  possible  which  should  exclude  from  its 
purview  the  part  played  in  it  by  uric  acid  ;  "    "  The  most  unequivocal 


GOUTY  PERICEMENTITIS.  521 

evidence  of  true  gouty  disease  is  that  derived  from  the  presence  of 
uratie  salts  in  the  tissues."  The  immediate  cause  for  the  deposition  of 
urates  in  individual  tissues  is  to  be  sought  for  in  a  special  vulnerability 
of  the  tissues,  a  loss  of  vitality,  the  result  of  mechanical,  chemical,  or 
vital  influences.  The  views  of  Ebstein  concerning  the  deposition  of 
uratie  salts  have  found  general  acceptance.  He  has  apparently  demon- 
strated that,  in  all  connective  tissues,  pjrvious  to  the  deposition  there  is 
a  primary  necrosis  of  tissue  elements  "without  which  the  crystallization 
could  not  take  place  ;  that  this  disturbance  of  tissue  vitality  is  the 
predisposing  factor  and  the  crystallization  the  exciting  factor  of  gouty 
changes.  The  blood  plasma  transuding  through  the  walls  of  the  capil- 
lary vessels  carries  with  it  urate  of  sodium  in  solution ;  in  the  partially 
devitalized  tissue  inspissation  occurs  and  in  consequence  crystallization. 

The  urate  of  sodium  as  it  accumulates  acts  as  a  specific  irritant  to 
the  tissue,  giving  rise  to  a  variety  of  phenomena  in  accordance  with  the 
character  of  the  tissue  involved.  The  gouty  manifestations  may  be 
either  acute  or  chronic.  In  the  acute  forms  the  signs  and  symptoms 
are  those  of  an  acute  specific  inflammation  of  a  joint,  usually  that  of  the 
great  toe.  Clinical  study  of  pyorrhea  cases  strongly  indicates  that  the 
disease  frequently  attacks  the  dento-alveolar  articulation  before  other 
articulations  in  point  of  time.  The  local  symptoms,  pain,  heat,  tume- 
faction are  associated  with  marked  constitutional  reactions,  disordered 
digestion,  and  numerous  evidences  of  general  disturbance  of  nutrition. 
The  duration  of  the  attack  may  be  from  a  few  days  to  several  weeks. 
Repeated  attacks  lead  to  an  impairment  of  the  functions  of  the  joint 
and  a  permanent  alteration  of  its  structure. 

In  the  chronic  forms  the  symptoms  are  more  widely  distributed  and 
their  intensity  is  less  pronounced  according  to  the  tissues  involved. 
The  various  manifestations  may  be  classified  as  follows  : 

Articular  gout,  in  which  the  deposit  occurs  in  joints. 

Tcf/tnnentari/  gout,  in  which  the  deposit  takes  place  in  the  skin  and 
mucous  membranes.  Disease  of  the  skin,  such  as  eczema  and  psoriasis, 
and  catarrhal  affections  of  the  mucous  membranes,  such  as  pharyngitis, 
chronic  bronchitis,  gastric  and  intestinal  catarrhs,  have  long  been 
recognized  as  expressions  of  gout. 

Visceral  gout,  in  which  the  deposit  occurs  in  the  viscera,  such  as  the 
lungs,  heart,  bloodvessels,  spleen,  liver,  kidneys,  i.  e.  giving  rise  to 
various  diseased  conditions  or  giving  a  peculiar  cast  to  disease  already 
established. 

Nervoufi  gout,  in  which  the  nervous  tissue  is  invaded,  manifesting 
itself  in  a  loss  of  mental  energy,  despondency,  irritalulity  of  temper, 
headaches,  neuralgia,  etc. 

The  limits  of  this  chapter  do  not  permit,  nor  is  it  desirable,  to  enter 


522  PYORRHEA  ALVEOLARTS. 

upon  a  detailed  statement  of  tlie  symptoms  or  diai>;nostic  features  of 
these  various  phases  of  the  gouty  diathesis  ;  sufliee  it  to  say  that,  under 
one  form  or  another,  tliey  are  fr(H(uently  })resent  and  associated  with 
pyorrhea  alveolaris.  The  pathology  of  ])ericemental  iiiliaiinnation  from 
uratie  (lep<^siti()n  unfolds  itself  logically  after  a  cou.sideration  of  the 
diathesis  in  its  constitutional  aspects,  l^earing  in  mind  the  fact  that  the 
alveolo-cemental  membrane  is  a  member  of  the  connective-tissue  group,  it 
is  not  at  all  sur})rising  that  it  also  should  become  the  seat  of  uratie  deposits. 

Pathology  of  the  Dental  Disease. — Unfortunately  the  anatomical 
relations  of  the  parts  and  other  factors  prevent  the  dental  observer  from 
collecting  a  complete  and  connected  series  of  observations  as  to  the  exact 
pathology  of  the  disease,  so  that  our  deductions  in  this  direction  are 
necessarily  confined  to  a  basis  of  clinical  records. 

It  is  a  natural  inference  that  the  pericementum  is  the  part  attacked 
because  it  is  a  point  of  minor  resistance.  The  decreasing  volume  of 
pericementum  which  attends  the  progress  of  the  disease  in  these  cases 
is  necessarily  followed  by  a  contraction  of  the  caliber  of  the  blood- 
vessels. It  is  not  at  all  improbable  that,  as  a  consequence  of  the  general 
physical  condition,  atheromatous  changes  occur  in  the  pericemental 
bloodvessels  leading  to  their  occlusion.  If  it  be  necessary,  as  some 
pathologists  maintain,  that  a  death  of  cells  precede  the  deposits  in 
gout,  this  vascular  change  will  account  for  the  necrosis.  The  acid  re- 
action of  the  necrotic  area  causes  the  deposition  of  urates,  which  are 
insoluble  in  acids. 

The  deposit  is  the  source  of  an  irritation  which  in  most  cases  is 
followed  by  inflammation,  leading  to  inflammatory  degeneration  and 
probably  coagulation  necrosis  of  the  cellular  elements.  The  alveolar 
walls  melt  down  particle  by  particle,  the  pericementum  disappears,  the 
diseased  area  usually  becomes  infected  by  pyogenic  organisms,  and  the 
process  of  suppuration  is  an  additional  factor  leading  to  the  exfoliation 
of  the  teeth.  As  in  necrotic  areas  of  other  parts,  calcareous  deposits 
occur,  which  cover  and  almost  entirely  obscure  the  primary  de})osit 
of  urates. 

The  condition  following  upon  a  deposit  at  the  lateral  aspect  of  a 
root,  in  its  pericementum,  is  shown  diagrammatically  in  Fig.  479.  At  a 
is  seen  the  calculus  embraced  by  a  territory  of  inflammatory  corpuscles, 
b.  The  pericementum  which  has  so  far  escaped  destruction  is  seen  at  c 
and  (/,  that  at  d  nourished  by  the  anastomosing  vessels  from  the  alve- 
olar periosteum.  At  a  later  period  this  portion  of  pericementum  be- 
comes involved  in  the  degenerative  process,  and  pus  escapes  at  the  neck 
of  the  tooth.  In  other  cases  the  inflammatory  degeneration  extends 
from  the  deposit  to  the  overlying  gum,  which   is  perforated. 

It  is  conceivable  that  such  tissue  changes  should  exist  in  consequence 


GOUTY  PERICEMENTITIS. 


523 


of  injuries  sustained  during  ordinary  dental  manipulations,  the  careless 
use  of  the  teeth  in  biting  unyielding  substances,  or  even  in  the  unwise 
use  of  toothpicks,  brushes,  etc.  This  supposition  granted — and  of  its 
truth  there  appears  to  be  much  evidence,  for  the  disease  not  unfrequeutly 


Fig.  479. 


Hematogenic  calcic  pericementitis  (Burchard). 

develops  after  the  operation  of  wedging,  malleting,  etc. — it  is  reasonable 
to  believe  that  during  the  transudation  of  lymph  through  the  lym})h 
channels  of  the  membrane,  cementum,  and  dentin  freighted  with  uratic 
salts,  deposition  and  crystallization  would  readily  take  place  in  tlie 
dento-alveolar  articulation  as  in  other  localities  of  the  body.  Not 
unfrequeutly  has  the  writer  recognized  pus-exuding  pockets  resulting 
solelv  from  wedwin^  or  lono'-continued  malleting,  and  these  in  teeth  that 
previously  to  the  oj^eration  were  as  free  from  any  appearance  of  either 
of  these  conditions  as  a  normal  tooth  could  be,  yet  an  idiosyncrasy 
or  predisposition  existed — the  exciting  cause  only  being  needed  to 
develop  it. 

With  this  deposit  and  accumulations  between  two  unyielding  bony 
surfaces  and  the  pressure  on  the  tissue  elements  in  consequence,  these 
salts  will  act  as  specific  irritants  and  engender  the  well-known  ])he- 
nomena — pain,  congestion,  swelling,  exudation,  impaired  nutrition, 
tissue  disorganization,  the  formation  of  pus,  an  osteomyelitis  resulting 
in  the  absorption  of  the  alveolar  process,  and  finally  the  exfoliation 
of  the  teeth  characteristic  of  pyorrhea  alveolaris.  The  most  general 
seat  for  the  deposition  of  tliese  salts  is  toward  the  apex  of  the  root, 
where  the  texture  of  the  alveolo-cemental  membrane  is  less  firm  and 
compact,  and  more  bulky. 


524  PVORRIIEA    A  L  VKOLA  RIS. 

The  supposition  that  pyorrhea  alveolaris  iis  a  local  expression  of  the 
general  tliatliesis  has  been  converted  into  an  actuality  by  the  demonstra- 
tion of  the  presence  of  uric  acid  and  its  allied  salts  in  the  incrustation 
found  on  the  roots  of  the  exfoliated  teetli.  The  eheniical  analyses  made 
by  Prof.  Ernest  ('ongdon  of  the  Drexel  Institute  have  demonstrated 
the  j)resence  of  these  salts  beyond  (juestion.'  All  of  the  established 
tests  for  uric  acid  were  emjjloyed  and  in  all  instances  crystals  of  uric 
acid,  sodium  urate,  and  calcium  phos])hate  were  detected.  In  several 
instances  sodium  urates  were  most  abundant.  The  constant  presence 
of  these  salts  on  the  surfaces  of  the  roots — the  presence  of  which  is 
ascertained  by  proper  analyses  and  aided  vision — taken  in  connection 
with  the  fiict  of  the  coexistence  of  gouty  disorders  in  other  tissues  justi- 
fies the  belief  that  the  form  of  pyorrhea  alveolaris  here  described  is  a 
gouty  inflammation. 

The  derivation  of  the  salts  from  the  blood,  the  abundance  of  the 
calcium  salts  present,  and  the  primary  hwation  of  the  inflammatory  pro- 
cess suggested  to  the  writer  the  term  hematogenic  calcic  pericementitis, 
though  it  is  admitted  that  the  single  epithet  gotdy  'pericementitis  would 
be  sufficiently  explanatory  and  descriptive.  The  succession  of  patho- 
logical states  is  readily  explained  and  justified  by  the  uratic  deposit. 
The  formation  of  pus  is  preceded  by  a  lowering  of  the  vitality  and  solu- 
tion of  the  pericemental  tissues.  This  having  been  accomplished,  the 
disintegrating  peridental  membrane  affords  a  favorable  nidus  for  the 
entrance  and  development  of  micro-organisms,  which  can  be  effected 
either  by  the  route  of  the  circulation  or  by  lesions  around  the  gum 
margins  which  give  opportunity  for  direct  infection  from  the  oral  fluids. 

When  organisms  once  gain  access  to  the  devitalized  tissue  they  mul- 
tiply with  great  rapidity,  and  in  so  doing  increase  the  disintegration  and 
solution  of  the  pericemental  membrane  with  the  formation  of  pus.  The 
specific  bacteria  which  have  been  demonstrated  to  be  present  in  the  pus 
are  the  usual  forms — the  staphylococcus  pyogenes  aureus,  citreus,  and 
albns — which  though  capable  of  producing  pus  are  not  pathogenic  in  the 
sense  that  they  are  the  causative  agents  of  the  pericementitis  with  the 
formation  of  an  abscess.  The  purulent  fluid  burrows  in  the  line  of 
least  resistance,  which  in  the  majority  of  cases  is  toward  the  gum  mar- 
gin, whence  it  is  discharged  into  the  mouth,  the  fistulous  tract  thus 
established  constituting  the  well-known  pyorrheal  pocket. 

By  the  continued  irritation  of  the  uratic  deposition  and  the  co-opera- 
tion of  micro-organisms,  the  inflammatory  process  extends  until  the 
membrane  is  destroyed  to  such  an  extent  that  it  is  no  longer  capable 
of  nourishing  and  supporting  the  teeth. 

The  absorption  of  the  alveolar  process  is  in  accordance  with  the  laws 
^  See  Infeiifialional  Dental  Journal,  1894,  vol.  xv.  p.  1. 


GOUTY  PERICEMENTITIS.  525 

governing  bone  softening  and  absorption  in  general.  Any  constant 
pressnre,  whether  from  infiamniatory  exntlation,  from  tnmors,  or  from 
mechanical  or  infective  agencies  which  interfere  with  its  nntrition,  will 
lead  to  softening  and  absorption.  In  pericementitis  the  effusion  exerts 
a  pressnre  in  both  directions,  toward  the  cementum  and  toward  the 
alveolar  walls ;  as  the  latter  are  spongy  in  character,  they  readily  yield 
to  the  absorptive  process.  Should  the  pressure  continue  indefinitely, 
or  until  the  alveolar  walls  become  denuded,  caries  or  necrosis  would 
inevitably  result.  Fortunately  this  termination  is  seldom  if  ever  seen  : 
the  most  careful  examination  of  the  alveolar  process  of  a  large  number 
of  patients  has  failed  to  show  any  alveolar  denudation ;  never,  in  the 
writer's  experience,  has  there  been  either  caries,  necrosis,  exfoliation, 
or  sequestration  of  bone.  Nor  could  there  be,  for  the  reason  that  the 
teeth  are  removed  either  naturally  or  artificially  before  complete  de- 
struction of  the  pericemental  membrane  has  been  accomplished.  With 
the  removal  of  the  teeth  and  its  associated  irritants  the  process  of  re- 
})air  at  once  begins.  The  dead  and  dying  tissues  are  removed,  and 
fibrous  tissues  make  their  appearance,  organization  is  established,  and 
in  a  short  time  all  traces  of  abnormal  action  have  disappeared. 

Diagnosis. — The  diagnosis  of  pyorrhea  alveolaris  becomes  compara- 
tively easy  when  its  constitutional  relations,  its  mode  of  origin,  its  prin- 
cipal symptoms  and  pathology  are  borne  in  mind.  The  only  diseases 
with  which  it  might  be  (indeed,  has  been)  confounded  are,  first,  that  form 
of  pericementitis  which  has  been  designated  a  ptyalogenic  calcic  peri- 
cementitis;  or,  second,  a  general  gingivitis  due  to  some  systemic  dis- 
turl,)ance  such  as  results  from  mercurial  ptyalisni  or  syphilis ;  or,  third, 
a  severe  inflammation  of  continuity  due  to  some  local  disturbance  such 
as  an  ill-fitting  partial  denture  or  an  imjiaeted  tooth,  possibly  a  third 
molar,  greatly  aggravated  by  some  morbid  systemic  condition.  These 
forms  of  pericementitis,  however,  present  many  points  of  contrast,  dif- 
fering in  their  clinical  history,  their  pathology,  symptomatology  and 
susceptibility  to  treatment.  In  the  hematogenic  forms  the  patient,  in 
the  great  majority  of  cases,  presents  some  other  manifestations  more  or 
less  pronounced,  of  the  gouty  or  rheumatic  diathesis. 

The  age  at  which  it  makes  its  appearance  is  usually  from  thirty-five 
to  fifty  years.  The  extreme  pain  frecjuently  present  around  the  roots  of 
one  or  more  teeth  in  the  early  stages,  and  before  there  is  any  evidence  of 
a  gingivitis  ;  the  deviation  in  the  position,  and  the  apjianmt  or  actual 
elevation  of  the  tooth,  with  response  to  pressiu'c  ;  the  swelling  or  thick- 
ening of  the  pericemental  mend)rane  ;  slight  tuuiefaction  of  the  gum 
with  deep  red  or  ])iu'plisli  color  oj)j)osite  the  a[)ieal  end  of  the  root  of 
the  tooth  or  teeth  affected — and  all  of  this  before  the  a])])earance  of  pus  ; 
the  isolated  character  of"  the  iullaminatiou,  being  usuallv  confined  to  one 


526  PYORRHEA    ALVEOLARIS. 

tooth  or  two  or  more  teotli  in  widely  separated  regions  of  the  mouth  ; 
the  exudation  and  discharge  of  pus  ah)ng  but  one  side  of  the  root, 
<letaching  the  gum  at  the  neck,  thus  establishing  a  sinus  or  ])us  pocket ; 
the  increase  of  the  flow  of  pus  from  llic  interior  of  the  alveolus  under 
])i'essure  ;  the  usually  limited  amount  of  cahnc  deposition  as  contrasted 
with  the  ])tval(\Q:enic  form  ;  the  destruction  of  the  pericemental  nu'm- 
brane  and  the  denudation  of  the  cementum  ;  the  absorj>tion  of  the 
alveolar  process;  the  loosening  and  exfoliation  of  the  teeth  indurated 
in  structure  and  changed  in  physical  apjK-arancc  are  the  main  charac- 
teristics of  the  disorder;  all  these  features  taken  in  their  totality  so 
individualize  this  disease  that  there  shoidd  be  no  difficulty  in  identi- 
fving  it. 

In  the  pfi/((/of/aiic  form  almost  the  ojiposite  conditions  })rcvail.  As 
a  general  rule  there  is  no  evidence  that  there  is  any  constitutional  diath- 
esis of  which  it  might  be  an  expression.  The  age  at  which  it  presents 
itself  extends  from  the  eighteenth  year,  sometimes  earlier,  to  any  period 
in  later  years,  varying  in  its  virulence  with  the  varying  systemic  condi- 
tions and  food  habits  of  the  individual.  The  ])resence  of  a  calcic  depo- 
sition around  the  neck  of  the  tooth  is  often  most  abundant;  the  primary 
gingivitis  occasioned  by  the  ])resence  of  this  mechanical  irritant  is  not 
confined  to  one  tooth  nor  to  isolated  regions  of  the  mouth  ;  the  subse- 
quent extension  (where  neglected)  and  infiltration  of  this  deposit  into 
and  beneath  the  pericemental  membrane ;  the  localization  of  the  sup- 
puration in  the  early  stages  around  the  margin  of  the  gums ;  the  de- 
layed loosening  of  the  teeth,  the  infrequent  loss  of  the  teeth  and  the 
susceptibility  to  successful  treatment  upon  the  removal  of  the  salivary 
deposit :  these  features  taken  together  fully  characterize  this  disease  and 
render  its  identification  easy. 

Contrasting  these  different  inflammatory  states  of  the  pericemental 
membrane  from  their  inception  to  their  termination,  it  becomes  evident 
that  distinct  yet  closely  allied  diseases  are  here  very  frequently  confused 
and  associated. 

Causation. — If  we  take  as  our  point  of  departure  the  postulate  that 
hematogenic  calcic  pyorrhea  alveolaris  is  but  a  special  manifestation  of 
the  gouty  diathesis,  we  should  expect  to  find  in  its  causation  the  same 
predisposing  and  exciting  agencies  operative  as  in  the  production  of  all 
other  manifestations  of  the  general  diathesis. 

Predisposing  Causes. — 1.  Heredity. — Among  the  predisposing 
causes  may  be  mentioned  heredity,  which  may  be  regarded  as  one  of 
the  most  important  factors  concerned  in  its  development.  The  writer 
feels  justified  in  asserting,  after  a  careful  investigation  into  the  fiimily 
history  of  a  large  number  of  pyorrhea  patients  that  fully  90  per  cent, 
inunifest  an  hereditary  tendency  to  this  disorder,  parents  and  grand-par- 


GOUTY  PERICEMENTITIS.  527 

ents  having  been  victims  of  the  same  disease.  Magitot  was  impressed 
with  the  significance  of  this  fact  years  ago,  and  stated  that  pyorrhea 
extended  through  two  and  three  generations  and  made  its  appearance 
at  corresponding  periods  of  life  and  in  similar  types  of  constitution. 

2.  Sex. — As  far  as  the  writer's  observations  extend,  sex  does  not 
appear  to  have  much  influence  in  the  production  of  pyorrhea,  women 
seeming  to  be  equally  affected  with  men ;  eliminate  the  masculine 
dietary  habit  and  there  would  certainly  be  little  diiference  in  the  pre- 
disposition to   the  disease. 

3.  Age. — The  age  at  which  pyorrhea  most  frequently  presents  itself 
is  the  period  of  middle  life — that  is,  between  the  ages  of  thirty  and 
fifty.  It  may  be,  though  it  is  very  rarely  seen  before  the  age  of 
thirty,  and  still  less  frequently  does  it  make  its  appearance  after  the 
age  of  sixty.  These  observations  are  corroborated  by  the  writings  of 
Magitot  and  others.  It  is  very  evident  that  pyorrhea  is  a  disease 
belonging  largely  to  a  period  of  life  when  growth  has  ceased  and  food 
is  required  only  for  tissue  repair  and  the  production  of  heat. 

4.  Diet. — A  careful  investigation  into  the  dietary  of  pyorrhea 
patients  will  disclose  the  fact  that  there  is  usually  a  consumption  of 
excessive  quantity  of  both  albuminous  and  starchy  foods,  much  more 
than  is  necessary  for  the  maintenance  of  the  nutrition,  and  more  than 
can  be  completely  oxidized  under  the  customary  or  existing  modes  of 
the  individual's  daily  life.  Coincidently  there  is  also  a  diminished 
consumption  of  water,  leading  to  an  imperfect  elimination  and  a  reten- 
tion of  the  products  of  this  incomplete  oxidation.  In  connection  with 
excessive  consumption  of  food  must  be  also  mentioned  as  co-operative 
factors  the  use  of  fermented  malt  liquors,  the  richer  claret  wines,  cham- 
pagnes, etc.  While  perhaps  no  one  class  of  foods  can  be  said  to  be 
especially  active  in  the  causation  of  pyorrhea  it  is  evident  that  exces- 
sive quantity  and  variety,  by  impairing  the  activity  of  the  digestive  appa- 
ratus and  giving  rise  to  a  large  quantity  of  nitrogenized  waste  products 
through  imperfect  oxidation,  would  materially  impair  and  lower  the  func- 
tional activity  of  the  system  generally  and  individual  tissues  in  particular. 

5.  Sedentari/  Oceiqxdlons. — Occupation  is  also  an  inq)ortant  factor 
in  the  production  of  pyorrhea.  In  the  majority  of  instances  the  disease 
makes  its  appearance  in  those  who  are  obliged  to  lead  lives  of  enforced 
inactivity — school  teachers,  accountants,  etc.  All  sedentary  occupations 
which  necessitate  insufficient  personal  exercise  Avill  favor  the  imperfect 
oxidation  of  food  and  at  the  same  time  retard  the  elimination  of  waste 
products. 

Exciting  Causes. — The  immediate  agency  in  the  development  of 
pvorrhea  is  undoubtedly  the  deposition  in  the  pericemental  mem- 
brane of   waste  products    of   nitrogenous   metabolism    in  c()m})ination 


528  PYORRHEA   ALVKOLARIS. 

with  calcium  salts  derived  from  the  blood.  This  morbific  matciial,  plav- 
iuiSi'  the  part  of  foreign  bodies,  irritates  and  excites  the  membrane  to 
infiammatorv  activity  and  all  its  attendant  symptoms.  But  even  ad- 
mittini;-  this  depositiou,  there  must  be  some  ])redisposition  on  the  part 
of  the  membrane  Avhich  makes  it  specially  liable  to  such  deposition. 
This,  it  is  believed,  is  in  harmony  Avith  gouty  deposition  in  all  other 
tissues  of  the  body  ;  it  is  to  be  found  in  im])aired  nutrition  and  lowered 
vitality  in  consequence  of  mechanical  strain  from  an  overcrowding  of 
the  dental  arch,  contusions  or  injuries  consequent  upon  the  usual  and 
aj)parently  unavoidable  dental  manipulations,  such  as  wedging  and 
malleting,  and  similar  procedures.  It  may  be  from  the  unskilful  em- 
ployment of  toothpicks,  toothbrushes,  etc. — though  these  latter  are  rare 
as  compared  with  other  acts  and  conditions  which  may  impair  the  nor- 
mal nutritional  condition  of  the  pericemental  membrane.  On  numer- 
ous occasions  where  the  predisposition  existed,  pyorrhea  has  devel- 
oped immediately  foUoM'ing  operations  upon  one  or  more  teeth.  Prof. 
Armand  Depres  ^  attributes  considerable  importance  to  the  overcroAvded 
condition  of  the  dental  arch  as  a  predisposing  cause  in  the  develop- 
ment of  pyorrhea. 

Treatment. — The  treatment  of  gouty  pericementitis  resolves  itself 
into  both  local  and  constitutional. 

The  local  treatment  is  to  be  directed  toward  removal  of  the  deposit 
and  the  control  and  the  suppression  of  the  inflammation  and  its  con- 
comitants, and  has  been  already  described  at  p.  511  in  connection  with 
the  study  of  ptyalogenic  calcic  pericementitis. 

Constitutional  Treatment. — Whatever  the  predisposing  cause  may  be, 
the  immediate  or  exciting  cause  must  ever  be  borne  in  mind.  This,  it 
is  believed,  to  a  certain  extent  at  least  is  found  in  all  of  those  mechani- 
cal agencies,  so  well  known  to  the  dentist,  which  impair  or  lower  the 
nutritional  level  of  the  pericementum,  thus  rendering  it  liable,  under 
certain  systemic  conditions,  to  a  deposition  of  uratic  salts.  The  ques- 
tion has  been  raised  as  to  why  the  membrane  of  one  or  more  teeth 
widely  separated  or  occupying  positions  on  opposite  sides  of  the  mouth, 
either  simultaneously  or  successively  becomes  the  seat  of  inflammation 
when  there  is  no  continuity  of  structure.  The  answer  to  this  must  be 
found  in  the  fact  that  impaired  nutrition  and  lowered  vitality  in  such 
structures  are  due  in  the  majority  of  instances  to  mechanical  injury  of 
these.  Malocclusion  may  be  noted  as  a  fruitful  cause.  It  is  certainly 
within  the  experience  of  many  observant  dentists  that  pyorrhea  has  not 
infrequently  developed  around  a  tooth  after  it  has  been  subjected  to  the 
necessary  mechanical  manipulations  incident  to  tooth  protection  and 
tooth  preservation. 

^  Legons  de  Clinique  chirurgicale,  p.  9-656. 


GOUTY  PEBICEMEJ^TITIS.  529 

This  apparent  interference  with  the  nntrition  of  the  pericemental 
membrane  before  the  deposit  of  uric  acid  salts  takes  place  is  in  accord- 
ance with  what  is  believed  to  hold  true  for  other  manifestations  of  the 
gouty  diathesis.  As  a  prophylactic  measure,  therefore,  it  is  suggested 
that  whenever  there  is  the  slightest  tendency  to  pyorrhea,  or  any  other 
evidence  of  the  gouty  diathesis,  great  care  should  be  exercised  in  all 
dental  operations,  so  as  not  to  impair  the  nutrition  of  the  pericementum 
and  thus  establish  the  necessary  condition  for  the  uric  acid  deposit ;  also 
correction  of  all  cases  of  malocclusion — surgical  rest  as* far  as  possible. 

The  constitutional  treatment  which  has  been  indicated  as  efficient  in 
the  elimination  of  already  established  uric  acid  conditions  and  the 
restoration  of  a  faulty  nutrition  to  its  normal  state  may  with  great 
propriety  be  subdivided  into  hygienic  and  medicinal. 

The  hygienic  treatment  embraces  systematic  outdoor  exercise,  stimu- 
lation of  the  functional  activity  of  the  excretory  organs,  the  skin,  bowels, 
and  kidneys,  and  regulation  of  the  diet,  which  must  be  insisted  upon  in 
all  well-marked  cases,  and  especially  with  those  who,  for  various  reasons, 
lead  sedentary  and  inactive  lives.  Increased  muscular  activity  quickens 
circulation,  induces  deeper  and  fuller  respiratory  movements,  leads  to 
greater  vigor  in  the  general  nutritive  processes  ;  waste  products  are 
removed  more  rapidly  and  the  combustion  of  the  food  increased  by  the 
absorption  of  a  large  amount  of  oxygen.  The  promotion  of  the  func- 
tional activity  of  the  eliminating  organs  is  well  recognized  as  an  import- 
ant hygienic  measure. 

The  perspiratory  and  sebaceous  glands  and  the  surface  capillary  circu- 
lation should  all  be  stimulated  by  sponging  of  the  skin  with  cold  water, 
vigorous  friction,  and  an  occasional  Turkish  bath,  where  such  treatment 
is  not  contraindicated  by  pulmonary  or  cardiac  aifections.  Where  the 
liver  and  intestinal  glands  are  deficient  in  secretion  with  prevailing 
constipation,  they  should  be  stimulated  into  activity  by  the  use  of 
saline  waters ;  most  excellent  for  this  purpose  being  the  Hunyadi  Janos 
and  Friedrichshalle.  These  are  especially  to  be  commended  because 
they  contain  a  large  percentage  of  sodium  and  magnesium  sulfates, 
both  of  which  are  useful  as  eliminating  agents. 

The  kidneys  should  be  assisted  in  the  excretion  of  waste  products 
by  the  free  use  of  negative  waters,  or  waters  in  which  the  saline  con- 
stituents are  present  in  minimum  quantity. 

Hot  or  distilled  water  in  sufficient  (piantity  will  flush  the  alimentarv 
canal,  increase  the  volume  of  blood,  and  stimulate  the  kidneys  to 
increased  activity.  It  is  not  only  a  common  observation,  but  rather 
a  remarkable  fact,  that  gouty  patients  are  inclined  to  drink  but  a  com- 
paratively small  quantity  of  water.  One  quart  of  hot  water  taken 
daily,  in  four  doses,  before  breakfast,  between  meals,  and  at  bedtime,  is 

34 


530  PYORRHEA   ALVEOLARIS. 

considered  most  beneficial  in  its  effects  in  dissolving:  and  rcniovinti-  ini- 
tatintj;  prodncts. 

The  most  imjwrtant  of  the  hygienic  nieasnrcs  in  the  trcatiucnt  ol" 
all  gonty  manifestations  is  that  pertaining  to  the  diet.  As  nric  acid  is 
a  nitrogenized  compound  and  therefore  presumably  one  of  the  imper- 
fectly oxidized  products  of  albuminous  or  nitrogenized  food,  it  is  desir- 
able that  such  foods  be  excluded  as  far  as  possible  from  the  daily 
diet.  The  value  of  this  measure  is  admitted  and  insisted  upon  by  all 
clinicians. 

In  the  milder  manifestations  of  the  gouty  diathesis  such  as  we 
assume  exists  in  pyorrhea,  it  is  not  so  imperative  that  all  albuminous 
food  be  prohibited ;  nevertheless,  as  many  ])atients  are  consumers  of 
large  quantities  of  meat,  it  would  be  well  to  insist,  if  the  effort  to 
cure  is  to  be  made,  upon  the  total  exclusion  of  beef,  veal,  mutton,  and 
pork,  restricting  the  patient  in  albuminous  diet  to  white  meat  of  fowl, 
oysters,  fish,  and  lobsters.  Cheese,  beans,  and  the  white  of  eggs  are 
considered  objectionable,  and  in  many  cases  of  acute  gout  are  strictly 
prohibited  by  the  attending  physician. 

Experience  has  shown  that  various  alcoholic  drinks,  such  as  cham- 
pagnes, port,  madeira,  and  sherry,  are  particularly  liable  to  give  rise  to 
the  accumulation  of  uric  acid.  The  lighter  wines,  as  claret  and  hock, 
are  not  considered  so  injurious.  The  malt  liquors,  beer,  ale,  and  porter, 
are  also  by  many  clinicians  considered  in  their  influence  to  be  great 
offenders. 

The  medical  and  constitutional  treatment,  it  is  obvious,  should  be 
directed  toward  the  elimination  of  uric  acid  and  its  compounds.  For 
this  purpose  remedies  which  promote  the  formation  of  soluble  and 
easily  diffusible  products  which  are  readily  eliminated  by  the  kidneys 
are  indicated.  From  time  immemorial  the  alkalies  and  alkaline  com- 
binations have  been  used  with  marked  success  in  the  management  of  all 
phases  of  the  gouty  diathesis. 

The  treatment  of  acute  gout  necessitates,  of  course,  different  or  more 
vigorous  remedies  than  those  required  for  the  subacute  or  chninic  forms 
with  which  the  dental  practitioner  will  be  called  upon  to  deal. 

Of  the  various  alkalies,  lithium  compounds — the  citrate  and  car- 
bonate— have  been  found  well  adapted  to  the  milder  phases  of  the 
disease.  The  writer  has  had  much  satisfaction  in  using,  on  the  sugges- 
tion of  Dr.  E.  C.  Kirk,  the  tartarlithine  lithium  bitartrate,  also  alka- 
lithia  prepared  in  the  same  form  as  the  above-named  compounds — com- 
pressed tablets  containing  five  grains  each  ;  one  tablet  three  or  four 
times  daily  will  be  found  sufficient.  Should  the  use  of  these  lithia 
tablets  not  agree  with  the  patient,  the  potassium  carbonate  in  ten-grain 
doses,  in  some  simple  bitter — gentian  or  quassia  water — three  or  four 


GOUTY  PERICEMENTITIS.  531 

times  daily,  may  be  sulxtituted.  A  valuable  adjunet  to  the  medicinal 
treatment  is  the  free  use  of  alkaline  waters,  which  assist  in  the  elimi- 
nation of  waste  products,  though  it  is  probable  that  the  good  effects 
attributed  to  these  are  largely  due  to  the  quantity  of  liquid  consumed. 

The  Saratoga,  Vichy,  alkaline  waters  of  Wisconsin,  the  ]Marienbad, 
Carlsbad,  Apollinaris,  etc.  have  all  been  found  efficacious.  Should 
the  patient  be  very  dyspeptic,  as  is  frequently  the  case,  remedies 
directed  to  the  digestive  viscera  are  of  course  indicated.  If  anemia  be 
a  concomitant,  iron  and  quinin  Avill  be  necessary.  A  combination 
which  has  been  found  of  great  value  in  improving  the  quality  of  the 
blood  is  one  of  iron  and  a  salt  of  potassium.  Bland's  pill,  consisting 
of  these  two  ingredients,  is  a  desirable  form  for  administration  ;  one 
three  times  a  day  will  be  sufficient. 

There  is  in  addition  one  factor  which  may  be  regarded  as  therapeutic 
or  at  least  prophylactic,  and  which  is  deserving  of  more  than  a  passing 
notice,  viz.  the  exercise  of  great  care  in  the  avoidance  of  injuries  to  the 
pericemental  membrane,  wherever  there  is  a  possibility  of  the  presence 
of  the  unfortunate  diathesis. 

However  ingenious  our  interpretation  of  pathological  conditions 
may  be,  and  however  plausible  our  deductions  may  appear,  the  ultimate 
test  of  their  value  will  be  the  readiness  with  which  they  yield  to  and 
disappear  under  approjiriate  treatment. 

If  pyorrhea  alveolaris  be  a  manifestation  of  the  gouty  diathesis,  and 
the  symptoms  and  pathological  conditions  which  characterize  it  be  ex- 
cited and  maintained  by  the  deposit  and  pressure  of  uric  acid  and  its 
salts,  it  should  be  in  general  terms  amenable  to  the  therapeutic  measures 
which  have  been  efficacious  in  the  treatment  of  all  other  forms  of  gout 
in  other  portions  of  the  body.  It  must  be  borne  in  mind,  however,  that 
though  a  case  be  cured  for  a  period  of  six  months,  or  even  a  year,  this 
does  not  preclude  a  relapse  should  the  patient  return  to  an  improper 
diet  or  irregular  mode  of  life.  It  is  hardly  necessary  to  say  that  this 
is  true  of  all  diathetic  diseases.  In  individuals  predisposed  to  uric  acid 
accumulations,  a  new  mode  of  life  is  to  be  instituted  and  followed  with 
extreme  care  for  a  long  period  of  time. 

The  conclusions  entertained  may  be  represented  in  a  condensed  form 
in  the  following  postulates  : 

(1)  Pyorrhea  alveolaris  of  constitutional  origin — which  is  its  most 
destructive  and  unyielding  form — primarily  begins  as  a  local  inflam- 
matory disorder  in  tissues  on  the  side  of  the  root  near  the  apical  ex- 
tremity, and  secondarily  advances  in  the  very  large  majority  of  cases 
toward  the  gingival  borders. 

(2)  The  cause  of  this  inflammation,  or  gingivitis  and  pericementitis, 
is  the  plasma  exudation  from   the  bloodvessels,  freighted  with  salts 


532  PYORRHEA    ALVEOLARIS. 

uliich  ill  their  deposition  and  crvstnllization  npon  tlic  ccnK'ntuin  ol'  the 
root  and  infiltration  of  the  more  vascnkir  tissnes,  exert  the  infinen(!e 
of  foreign  bodies  and  reaet  as  irritants. 

(3)  The  salts  in  question,  as  disclosed  by  chemical  analysis,  are  cal- 
cium and  sodium  urates,  free  uric  acid,  and  calcium  phosphate. 

(4)  The  chemical  nature  of  these  salts  indicates  a  condition  of  the 
bli)()d  in  which  there  is  an  excess  of  uratic  salts  and  uric  acid  due  to 
either  hicrcased  formation  or  imperfect  eliminatiou. 

(5)  The  excess  of  these  salts,  as  is  well  known,  is  regarded  by  gen- 
eral pathologists  as  indicative  of  a  faulty  metabolism,  and  is  the  imme- 
diate cause  of  a  series  of  local  disturbances  to  which  the  term  gouty  has 
been  applied,  the  nutritional  disturbance  giving  rise  to  what  is  known 
as  the  "  uric  acid  diathesis." 

(G)  An  attentiye  study  and  accurate  observation  of  the  various 
organs  and  tissues  of  patients  suffering  with  jn'orrhea  alveolaris  have 
disclosed  the  coexistence,  in  a  very  large  proportion  of  them,  of  one  or 
more  local  expressions  of  this  constitutional  diathesis. 

(7)  Ivecognition  of  the  fact  that  a  constitutional  malady  presents 
itself,  one  phase  of  which  only  has  claimed  the  attention  of  the  dental 
practitioner,  indicates  that  a  treatment  designed  to  be  curative  must 
have  reference  not  only  to  the  local  exi)ression,  but  especially  to  this 
important  systemic  condition  as  well. 

(8)  llesults  from  constitutional  treatment  in  connection  with  the 
usual  local  applications  in  a  ninnbei-  of  well-authenticated  cases  of 
pyorrhea  alveolaris  have  been  so  markedly  satisfactory  that  the  writer 
feels  fully  justified  in  his  assumptions  regarding  the  origin  of  the 
disease. 

While  the  foregoing  pages  embody  views  quite  consistent  with  an 
extended  experience,  yet  the  writer  fully  a})preciates  the  fact  that  many 
abnormal  conditions  closely  allied  in  superficial  characteristics  to  those 
above  recognized  and  described  may  exist  without  any  other  local 
expressions  indicating  a  uric  acid  dyscrasia. 

The  association  of  the  class  of  dental  diseases  included  under  the 
generic  title  of  pyorrhea  alveolaris  with  conditions  of  general  mal- 
nutrition has  been  recognized  by  many  writers  during  the  past  hun- 
dred years,  but  until  within  very  recent  times  no  systematic  attempt 
had  been  made  at  their  classification.  Dr.  M.  L.  Khein,  who  has 
closely  studied  the  relations  existing  between  general  disorders  and  the 
dental  diseases,  finding  that  many  general  diseases  are  accompanied  by 
the  symptom  pyorrhea  alveolaris,  and  that  the  dental  disorder  persists 
so  long  as  the  general  disease  is  in  activity,  suggests  that  the  diseases 
known  under  the  latter  title  be  diyided  into  two  classes — pyorrhcd 
simplex  and   pyorrhea  complc.r. 


GOUTY  PERICEMENTITIS.  533 

Under  the  head  pi/orr/ica  simplex  are  inchided  all  of  those  varie- 
ties and  cases  in  which  local  therapeutic  measures  suffice  to  effect 
a  cure.' 

Pyorrhea  complex  covers  those  cases  and  varieties  in  which  local 
therapeusis  fails  to  subdue  the  dental  disease,  and  which  are  associated 
with  some  perversion  of  general  nutrition.  This  class  is  subdivided 
intofourgroups  :  (o)  Those  due  to  nutritional  disorders  such  as  gout, 
diabetes,  chronic  rheumatism,  nephritis,  scurvy,  chlorosis,  anemia, 
leukemia,  pregnancv  ;  {b)  Tiiose  occurring  during  attacks  of  acute  infec- 
tive diseases,  as  typhoid  fever,  tuberculosis,  malaria,  acute  rheumatism, 
pleurisy,  pericarditis,  syphilis;  (e)  Those  due  to  nervous  disorders, 
cerebral  diseases,  spinal  diseases,  neurasthenia,  hysteria  ;  ((/)  Con- 
ditions resulting  from  the  action  of  toxic  drugs — mercury,  lead, 
iodids. 

Dr.  Rhcin  believes  from  his  studies  that  each  member  of  the  group 
of  pyorrhea  complex  has  a  distinctive  clinical  expression,  which  might 
be  utilized  as  diagnostic  signs  of  the  constitutional  conditions. 

One  who  is  familiar  with  oral  abnormalities  and  able  to  diiferentiate 
them  must  be  very  liberal  in  the  interpretation  of  causes  in  order  to 
embrace  the  wide  range  of  pathological  conditions  which,  in  some  stages 
of  development,  present  appearances  that  would  or  could  very  properlv 
be  termed  pyorrhea  alveolaris,  yet  whose  very  ready  response  to  t()i)ical 
remedies  would  naturally  suggest  that  they  were  not  associated  with  a 
uric  acid  hal)it.  While  fully  recognizing  the  fact  that  this  uric  acid 
dyscrasia  can  be  associated  Avith  almost  any  disease  which  is  a  concomi- 
tant of  malnutrition,  we  must  remember  and  fully  appreciate  the  fact 
that  imperfect  assimilation  of  food  and  faulty  metabolism  are  often 
responsible  for  local  abnormalities,  and  at  the  same  time  they  mav  be 
factors  in  the  establishment  of  a  uric  acid  dyscrasia. 

In  one's  judgment  of  the  soundness  or  unsoundness  of  theories  or 
hypotheses,  the  fact  must  not  be  overlooked  that  aifections  of  the  kid- 
neys, the  liver,  the  lungs,  the  heart,  the  mucous  membrane,  the  stomach, 
etc.  may  exist  without  any  other  recognized  expression,  or  we  may  have 
irritation  of  the  pericemental  membrane  alone  associated  with  any  one 
of  them,  the  disturbance  of  the  normality  of  this  tissue  being  severe  or 
slight  as  the  functional  or  organic  abnormality  of  the  organ  is  exalted 
or  inconspicuous. 

While  in  the  previous  pages  the  treatment  advocated  had  reference 
mainly  to  that  form  of  pyorrhea  the  concomitant  of  the  gouty  diathesis, 
it  must  nevertheless  be  borne  in  mind  that  a  similar  condition  of  the 
])ericemental  membrane  is  at  tiines  associated  with  other  perversions  of 
the  general  nutrition,  as  pointed  out  by  Dr.  M.  I^.  Rhcin,  and  wliich 
'  Venial  Cosmos,  1894,  p.  780. 


534  PYORRHEA  ALVEOLA RIS. 

therefore  must  receive  treatment  especially  adapted  to  the  general  con- 
stitutional state. 

Inasmuch  as  these  constitutional  conditions  are  complex  in  their 
manifestations  and  their  medicinal  and  liyt>:icnic  management  almost 
exclusively  in  the  hands  of  the  physituan,  the  duty  of  the  dental  i)rac- 
titioner  is  confined  largely  to  the  question  of  diagnosis  ;  the  local  treat- 
ment, however,  must  be  varied  in  accordance  with  the  peculiarities  of 
the  local  pathological  condition. 


CHAPTER    XX. 

DISCOLORED  TEETH   AND  THEIR  TREATMENT. 

By  Edavaed  C.  Kirk,  D.  D.  S. 


Discoloration  of  a  tooth  is  consequent  upon  death  of  its  pulp. 
"While  death  of  the  pulp  does  not  always  or  necessarily  involve  dis- 
coloration of  the  tooth  structures,  yet  ^\\\en  the  condition  does  exist  the 
general  cause  is  as  stated.  Reference  is  here  nuule  to  a  progressive 
interstitial  staining  of  the  entire  dentin  structure,  and  is  exclusive 
of  certain  metallic  stains,  and  also  localized  stains  resulting  from  the 
imbibition  of  pigmentary  matters  which  occasionally  are  observed  where 
small  areas  of  dentin  have  become  denuded  of  enamel  covering,  or 
where  the  latter  has  been  so  imperfectly  formed  as  to  afford  an  in- 
sufficient barrier  to  the  ingress  of  pigmentary  matters  from  the  food 
or  oral  secretions. 

Three  classes  of  conditions  are  presented  for  consideration  and  treat- 
ment :  First,  cases  where  discoloration  has  resulted  from  death  of  the 
pulp  due  to  causes  other  than  its  exposure  ;  second,  discoloration  from 
])ulp  death  consequent  upon  exposure  ;  and  third,  special  discolorations 
due  to  adventitious  causes  superadded  to  the  conditions  affecting  the 
cases  included  in  the  foregoing  second  division. 

Any  of  the  numerous  traumatic  causes  which  bring  about  death  of 
the  pulp,  e.  g.  blows,  sudden  contact  with  hard  substances,  biting 
threads,  violent  thermal  shocks,  the  injudicious  application  of  continuous 
force  in  regulating,  or  the  application  of  arsenous  oxid  to  the  dentin 
(see  p.  425),  where  no  exposure  or  only  minute  exposure  of  the  pulp 
exists,  may  produce  hyperemia  and  congestion  of  the  pulp,  or  strangu- 
lation of  its  circulatory  system,  the  formation  of  emboli,  thrombus, 
hemorrhagic  infarct,  etc.,  leading  to  a  breaking  down  of  the  corpus- 
cular elements  of  the  blood,  the  escape  of  hemoglobin  from  the  stroma 
of  the  red  corpuscles,  its  solution  in  the  blood  plasma,  and  resulting 
infiltration  of  the  tubular  structure  of  the  dentin  by  the  hemoglobin 
solution,  giving  the  tooth  a  distinctly  pinkish  hue  when  examined  by 
direct  or  transillumination. 

Teeth  so  affected  rapidly  change  in  color  through  various  gradations 
in  tint  from  the  original  pinkish  hue,  which  becomes  yellow^ ;  this,  grow- 
ing darker,  passes  into  brown,  and  after  the  lapse  of  considerable  time 
the  tooth  may  become  a  permanent  slaty  gray  or  black. 

535 


536  DISCOLORED   TEETH  AND    THETR    TREATMENT. 

The  violence  of  the  pulpitis  preceding  the  death  and  disintegration 
of  the  pulp,  in  a  considerable  degree  determines  the  rapidity  of  the 
])rocess  of  subsequent  tooth  discoloration.  AVhere  congestion  of  the 
pulp  has  been  relatively  slight  and  the  necrotic  process  has  proceeded 
slowly,  the  sudden  infiltration  of  the  dentin  with  hemoglobin  does  not 
occur,  consequently  the  initial  change  in  color  following  complete  death 
of  the  pulp  may  be  so  slight  as  to  escape  detection  except  ujion  most 
searching  examination  with  special  means  of  illumination,  and  even 
then  may  be  manifested  only  by  a  slight  diminution  in  the  normal 
translucency  of  the  tooth  as  compared  with  adjoining  teeth.  Such  teeth, 
however,  if  permitted  to  remain  untreated,  eventually  grow  darker, 
and  while  they  may  not  acquire  a  degree  of  discoloration  equal  to  those 
which  have  suffered  sudden  and  violent  death  of  the  pulp,  still  they 
become  so  unsightly  as  to  demand  treatment  for  the  restoration  of 
their  normal  color. 

The  Rationale  of  the  Process  of  Discoloration. — In  teeth  dis- 
colored as  a  consequence  of  the  death  of  the  pulp  without  its  exposure  — 
viz.  those  of  the  first  class — it  is  evident  that  the  sources  of  pigmenta- 
tion are  internal  to  the  tooth  and  are  to  l)e  sought  for  solely  in  the 
products  of  decomposition  of  the  elements  of  the  pulp  tissue  and  of  its 
vascular  supply. 

The  proteid  elements  of  the  pulp  tissue  are  complex  cond>inations 
of  carbon,  oxygen,  hydrogen,  nitrogen,  sulfur,  and  phosphorus,  which 
in  their  gradual  breaking  down  by  the  process  of  putrefactive  decom- 
position are  split  up  finally  into  carbon  dioxid,  water,  ammonia,  and 
hydrogen  sulfid,  with  possibly  the  formation  of  traces  of  phos])hatic 
salts.  The  group  of  substances  entering  into  the  composition  of  the 
histological  elements  of  pulp  tissue  contains  no  constituents  which  in 
the  progressive  changes  resulting  from  putrefactive  decomposition 
should  form  compounds  likely  to  cause  permanent  discoloration  of 
the  tooth  structures. 

When,  however,  the  vascular  supply  is  considered  as  a  factor,  the 
explanation  of  the  cause  of  discoloration  in  the  cases  in  question 
becomes  reasonably  clear.  The  red  blood  corpuscles  contain  as  their 
characteristic  component  hemoglobin  or  oxyhemoglobin  according  as  the 
blood  is  venous  or  arterial,  and  this  substance  is  its  essential  coloring 
ingredient.  When  undergoing  gradual  decomposition,  hemoglobin 
passes  through  a  variety  of  alterations  in  its  chemical  constitution, 
accompanied  by  a  corresponding  series  of  color  changes. 

A  familiar  illustration  of  these  color  changes  is  furnished  by  the 
cycle  of  color  alterations  witnessed  in  a  bruise.  Immediately  following 
on  injury  to  the  flesh,  of  the  character  alluded  to,  an  extravasation  of 
blood  in  the  bruised  territory  occurs,  causing  undue  reddening  of  the 


RATIONALE  OF  THE  PROCESS  OF  DISCOLORATION.  537 

skin  ;  tliis  is  soon  followed  by  an  increasing  darkening  of  the  tissue, 
until  there  results  what  is  popularly  termed  a  "  black-and-blue  spot," 
Further  decomposition  of  the  coloring  matter  of  the  extravasated  blood 
induces  a  variety  of  color  changes  ranging  through  the  scale  of  yellows 
and  browns,  until  the  pigmentary  matter  is  finally  removed  by  absorp- 
tion through  the  capillary  bloodvessel   system  of  the  part. 

In  passing  through  its  cycle  of  color  changes,  hemoglobin  undergoes 
several  alterations  in  composition  during  which  a  number  of  definite 
compounds  are  formed,  each  having  marked  chromogenic  features.  Of 
these  decomposition  products,  methemoglobin  (brownish  red),  hemin 
(bluish  black),  hematin  (dark  brown  or  bluish  black),  and  hematoidin 
(orange),  are  the  most  important  and  best  know^n.  While  the  gradual 
decomposition  of  the  coloring  matter  of  the  blood  here  noted  may  and 
<loubtless  does  account  for  certain  phases  of  tooth  discoloration,  other 
factors  which  exert  a  })rofoundly  modifying  influence  upon  the  process 
are  yet  to  be   considered. 

The  putrefactive  decomposition  of  the  proteid  elements  of  the  pulp 
results,  as  before  stated,  in  the  production  of  hydrogen  sulfid  in  con- 
siderable quantity.  The  albumins  contain  from  0,8  to  2,2  per  cent,  of 
sulfur  (Hammarsten)  which  in  the  splitting  up  of  the  compound  during 
putrefaction  yields  a  large  amount  of  hydrogen  sulfid.  In  pulp  decom- 
position this  hydrogen  sulfid  is  generated  in  contact  with  the  hemoglobin 
and  necessarily  exerts  a  marked  modifying  action  upon  the  decomposi- 
tion process  of  that  substance.  Miller  says,  "  If  a  current  of  sulfuretted 
hydrogen  is  conducted  through  fresh  blood  or  a  solution  of  oxyhemo- 
globin in  the  presence  of  air  or  oxygen,  sulfomethemoglobin  is  formed, 
which  is  greenish  red  in  concentrated  solutions  and  green  in  dilute  solu- 
tions. If  we  lay  a  freshly  extracted  tooth  in  a  mixture  of  meat  and 
saliva  so  that  a  part  of  the  enamel  surface  remains  free,  and  moisten 
the  surface  with  blood,  it  will  take  on  a  dirty-green  color  if  kept  at 
blood  temperature  in  an  absolutely  moist  condition  for  from  twenty-four 
to  forty-eight  hours.  It  is  quite  possible  that  the  dirty-green  deposits 
which  form  in  putrid  conditions  of  the  mouth,  in  stomatitis  mercurialis, 
S(!orbutica,  gangrenosa,  etc,  or  even  in  inflammatory  conditions  of  less 
importance,  as  well  as  in  cases  of  absolute  neglect  of  the  care  of  the 
mouth,  may  owe  their  green  color  to  the  presence  of  sulfomethemo- 
globin," 

As  in  pulp  decomposition  hydrogen  sulfid  is  being  formed  in  the 
presence  of  hemoglobin,  this  llict  warrants  the  belief  that  a  combina- 
tion takes  place  resulting  in  the  formation  of  this  same  compound, 
which  Miller  regards  as  ])rodu('tive  of  certain  stains  upon  the  external 
surface  of  the  teeth. 

The  slaty  gray  or   bluisii    [)igni('ntati()n  always   noticeable   uj)on  the 


5:^S  DISCOLORED  TEETH  AND   THEIR   TREATMENT. 

visceral  walls  and  IVccjiiciitly  beneath  the  skin  of  animal  bodies  under- 
goiiiii'  })ntret;u^tive  de42;enei'ati(>n  is  a  I'aniiliar  example  of"  the  action  ot" 
hvdrog'cn  snllid  npon  decomposinjj:;  hemot>;lol)in  in  hemorrhagic  extrava- 
sations, and  is  a  ])rocess  and  ibrm  of  pigmentation  exactly  analogous  to 
tl.at  wliich  is  here  described  as  taking  place  in  the  dentinal  strnctnre 
from  putrelhctivc  decomposition  of  the  pulj).  "  When  red  corpuscles 
arc  just  beti'inning  to  disintegrate,  the  coloi"ing  mtitter  formed  is  hemo- 
globin ;  but  the  yellow  and  brown  granidar  masses  found  in  cells  and 
lying  free  in  tissues  are,  as  a  rule,  derivatives  of  hemoglobin,  not  hemo- 
globin itself.  These  derivatives  are  divided  into  two  groups  according 
as  they  contain  iron  or  not,  the  former  being  called  hemosiderin,  the 
latter  hematoidin."  '  "  When  acted  upon  by  ammonium  sulfid  (a  deriv- 
ative of  putrefactive  decomposition  of  albumin)  hemosiderin  becomes 
black,  iron  sultid  being  formed."^  Grohe'^  believes  that  as  a  result  of 
putrefaction  iron  is  liberated  from  its  compound  with  hemoglobin,  so 
that  when  thus  freed  it  readily  combines  with  the  hydrogen  snllid. 

Iron  is  the  most  important  element  to  be  considered  in  the  list  of 
factors  causing  the  discoloration  of  this  group  of  cases.  It  is  the  iron 
constituent  of  the  red  corpuscles  Avhich  is  the  essential  chromogenic 
factor  from  first  to  last  in  their  cycle  of  color  changes. 

The  process  of  putrefactive  decomposition  consists  of  a  series  of 
chemical  changes  wrought  out  through  the  agency  of  micro-organisms, 
involving  the  breaking  down  by  successive  stages  of  highly  complex 
organic  compounds  and  their  resolution  into  compounds  of  much  sim- 
pler constitution.  It  is  not  known  to  what  extent  this  splitting  up  of 
the  components  of  the  pulp  and  its  vascular  elements  is  ultimately  car- 
ried in  the  series  of  changes  resulting  in  the  permanent  discoloration 
of  the  tooth.  From  what  is  known  of  the  ultimate  composition  of  the 
compounds  involved  it  may,  howev(>r,  be  safely  inferred  that,  reduced 
to  its  lowest  terms,  the  result  would  be  the  formation  of  iron  sultid,  the 
elements  of  which,  with  the  exception  of  some  unimjiortant  alkaline  and 
earthy  salts,  are  the  only  ones  entering  into  the  original  compounds 
which  are  fixed  and  therefore  capable  of  forming  a  stable  residuum  in  the 
tubular  structure  of  the  dentin.  While  iron  sulfid  as  such  cannot  be 
held  wholly  accountable  for  the  final  bluish-black  color  of  a  tooth  which 
has  reached  the  stage  of  permanent  discoloration,  the  pigmentation  is 
almost  certainly  due  either  to  it  or  to  some  allied  compound  in  which 
iron  and  sulfur,  with  some  organic  constituents,  largely  enter,  and  which 
by  a  further  slight  decomposition  would  yield  true  iron  sultid. 

The  significance  and  importance  of  a  recognition  of  the  possible 
))rcsence  of  the  iron  compound  as  a  factor  in  tooth  discoloration  is 
further  brought  out  in  the  study  of  bleaching  methods  (pp.  542  and  558). 

'  Ziegler,  General  Putholof/y,  1895.  '^  Ibid.  ^  Virchow's  Archiv.,  Bd.  xx. 


DISCOLORATION  FOLLOWING  DEATH  OF  THE  PULP.         539 

Discoloration  of  Teeth  follo^w^ing-  Death  of  the  Pulp  consequent 
upon  its  Exposure. — When  death  and  deeonipusition  of  the  pulp  is 
consequent  upon  exposure  of  that  organ,  throngli  earies  or  otherwise,  to 
the  irritative  influences  of  infective  agents  present  in  the  oral  secretions 
and  food,  or  to  thermal  shock,  etc.,  the  pntrefactive  process  involving 
the  pulp  tissues  is  modilied  in  character  and  rapidity  to  a  degree  which 
may  affect  the  character  of  the  resulting  discoloration.  Thus  the  yel- 
lowish or  brownish  discoloration  so  often  seen  in  teeth  whose  pulps 
have  been  devitalized  through  systemic  or  traumatic  causes,  and  which 
in  many  cases  appears  to  be  more  or  less  permanent  in  character,  is 
rarely  observed  in  those  teeth  whose  pulps  have  been  devitalized  through 
exposure  by  caries.. 

In  these  latter  cases  the  progress  of  the  putrefactive  process  is  com- 
paratively ra})id,  the  conditions  being  more  favorable  so  that  the  color- 
ing matter  of  the  blood  is  sooner  reduced  to  its  lowest  terms  in  the  scale 
of  decomposition  products,  /.  e.  to  the  slaty  blue  or  black  pigmentation 
before  noted.  In  addition  to  the  increased  rapidity  of  putrefactive  de- 
coniposition  incident  to  cases  of  discoloi'ation  following  pulp  exposure, 
another  and  ini])ortant  modifying  factor  in  the  process  of  discoloration 
is  the  ingress  aflPorded  to  the  oral  fluids,  food  materials,  and  other  ad- 
ventitious substances  which  find  their  way  into  the  mouth  and  ulti- 
mately, through  the  o})en  cavity  of  the  tooth,  to  its  pulp  canal  and 
thence  to  the  tubular  structure  of  the  dentin.  These  extraneous  sub- 
stances, in  the  course  of  time,  may  infiltrate  tlie  tooth  stnicture,  and 
while  no  especially  noticeable  or  characteristic  effect  may  be  observed 
so  far  as  color  is  concerned,  yet  they  frequently  exert  an  inflnence  upon 
the  coloration  of  the  tooth  which  so  alters  its.  character  as  to  render 
successful  bleaching  treatment  extremely  difficult  and  a  resort  to  special 
methods  or  a  variety  of  methods  necessary. 

The  introduction  of  fatty  or  oily  substances  or  of  astringent  and 
coagulant  matters,  for  example,  may  act  upon  the  coloring  matter  in 
such  a  way  as  to  permanently  "  set "  it  in  the  same  manner  that  mor- 
dants form  insoluble  compounds  or  lakes  with  the  dye-stufls  used  in 
the  dyeing  of  textile  fabrics. 

Another  and  important  class  of  substances  which  frequently  are  the 
cause  of  staining  of  the  tooth  structure  are  metallic  salts  which  are  used 
in  dental  therapeutic  treatment  or  are  accidentally  formed  (hiring  the 
a])])lication  of  corrosive  medicaments  to  the  teeth,  through  the  action  of 
such  remedies  npon  fillings  in  xif^i  or  upon  the  instruments  by  which 
the  applications  are  made.  For  example,  the  use  of  iodin  or  sulfuric 
acid  in  connection  with  steel  instruments  and  the  snbsequent  use  of 
medicaments  containing  tannin  as  an  ingredient. 

The  treatment  of  these  conditions  will  be  se})arately  considered. 


540  DISCOLORED   TEETH  AND   TlIKIli   TREATMENT. 

Tooth-Bleaching. — Use  of  Chlorin. 

Nature  of  the  Problem  Involved  in  Tooth-Bleaching-. — The 
bleaching  process  is  (lependeiit  upon  a  elieniical  reaction  betwecai  a  com- 
pound liavino-  color  and  some  substance  capal)le  of  so  atrectin(>;  its  (!om- 
j)osition  that  the  color  is  discharged,  or,  in  other  words,  of  so  atfecting 
the  integrity  of  the  color  molecule  as  to  destroy  its  identity,  which 
results  in  a  loss  of  its  distinguishing  characteristic,  viz.  its  color. 

The  substances  concerned  in  discoloration  of  tooth  structure,  as  has 
been  previously  shown,  are  derived  from  the  pulj)  and  its  vascular 
elements  and  the  organic  contents  of  the  tubular  structure  of  the  dentin, 
through  the  gradual  putrefactive  processes  which  become  operative 
subsequent  to  the  death  of  the  ])ulp.  These  pigmentary  products  of 
pulp  decompositiou  we  know  to  be  organic  in  character;  and  further, 
that  they  exhibit  the  ])roperty  of  color  by  virtue  of  definite  conditions 
of  molecular  composition — that  is  to  say,  a  certain  arrangement  of  a 
definite  kind  and  number  of  atoms  has  resulted  in  the  formation  of  a 
molecule  having  its  individual  group  of  chemical  and  physical  prop- 
erties, among  which  latter  is  a  characteristic  color. 

Whatever  brings  about  an  alteration  in  the  composition  of  the  mole- 
cule at  once  destroys  the  identity  of  the  matter  so  treated.  Hence  if 
we  can  act  upon  the  coloring  matter  which  gives  rise  to  the  staining  of 
a  tooth  by  means  of  an  agent  capable  of  effecting  an .  alteration  in  the 
atomic  arrangement  or  composition  of  the  color  molecule,  we  may  expect 
to  remove  or  discharge  its  color  feature. 

Two  general  classes  of  substances  have  been  successfully  used  as 
bleaching  agents  :  First,  those  whicli  act  by  virtue  of  their  power  to 
evolve  oxvgen  in  the  active  or  nascent  condition,  and  known  as  oxidiz- 
ing agents  ;  second,  those  which  act  in  an  opposite  manner  by  virtue 
of  their  strong  affinity  for  oxygen  and  which  are  called  reducing  agents. 
The  oxidizing  bleachers  destroy  the  identity  of  the  color  molecule  by 
seizing  upon  its  hydrogen  element  to  form  water.  The  reducing  agents 
act  bv  removing  the  oxygen  atom  from  the  color  molecule  to  form  by- 
products depending  ui)on  the  character  of  the  reducing  agent  used. 

Chlorin  and  its  associates  iodin  and  bromin  act  as  indirect  oxidizing 
b/cachers;  the  dioxid  of  hydrogen  and  of  sodium  are  direct  oxidizers. 
Potassium  permanganate  may  also  be  classed  with  this  group,  though  its 
successful  use  as  a  bleaching  agent  depends  upon  a  subsequent  treat- 
ment of  the  substance  to  be  bleached  with  some  solvent  capal)le  of  re- 
moving the  manganese  dioxid  formed  as  a  by-product  of  the  action  of 
the  permanganate.  It  has  somewhat  extensive  and  satisfiictory  use  as 
an  agent  for  bleaching  sponges,  and  has  been  used  for  bleaching  teeth, 
but  is  of  greatly  inferior  value  to  other  agents  for  the  latter  use. 


TOOTII-BLEACHING—USE   OF  ClILORIN.  541 

The  only  agent  belonging  to  the  group  of  reducing  bleachers  which 
has  thus  far  been  found  available  for  bleaching  teeth  is  sulfurous  oxid, 
either  in  the  gaseous  coudition  or  in  aqueous  solution. 

Chlorin  as  a  Bleacher. — The  general  use  of  chlorin  as  a  bleaching 
agent  in  the  arts  no  doubt  suggested  its  use  in  the  treatment  of  tooth 
discoloration.  Its  introduction  as  a  tooth-bleaching  agent,  as  well  as  the 
assembling  of  the  general  principles  of  tooth  bleaching  into  a  co-ordi- 
nate system,  are  due  to  Dr.  James  Truman,  whose  method  depends  upon 
the  liberation  of  chlorin  from  calcium  hypochlorite,  commonly  called 
bleaching  powder  or  "chlorinated  lime,"  in  the  pulp  chamber  and  cav- 
ity of  decay  in  the  tooth.  Chlorin  is  liberated  from  the  bleaching  pow- 
der by  the  action  of  dilute  acetic  acid  ;  this  taking  place  in  contact  with 
the  discolored  structure,  it  is  rapidly  bleached  as  a  result  of  the  action 
of  the  chlorin  upon  the  coloring  matter  contained  in  the  dentinal  tubules. 
Numerous  modifications  of  this  original  method  of  bleaching  tooth  struc- 
ture have  been  suggested,  but,  as  the  ultimate  result  in  each  is  accom- 
plished through  the  activity  of  chlorin,  a  rational  understanding  of  the 
mode  of  action  of  chlorin  in  this  relation  is  of  importance  as  an  aid 
to  the  intelligent  use  of  those  methods  for  tooth-bleacliing  which  are 
dependent  upon  or  owe  their  efficacy  to  that  agent. 

Chlorin  is  an  elementary  gaseous  body,  greenish  in  color,  soluble  in 
water,  iiaving  a  disagreeable  odor,  intensely  irritating  to  the  air-passages 
when  inhaled,  and  poisonous  when  breathed  in  sufficient  quantity.  It 
has  a  strong  affinity  for  all  metallic  bodies,  entering  into  direct  combi- 
nation with  a  number  of  tliem,  under  favorable  circumstances,  with 
great  energy — forming,  as  a  rule,  compounds  that  are  soluble  in  water. 

One  of  its  distinguishing  features  and  one  which  is  directly  concerned 
in  its  use  as  a  bleaching  agent  is  its  strong  affinity  for  hydrogen.  So 
strong  is  this  affinity,  that  when  a  molecule  of  chlorin  is  brought  into 
contact  with  a  molecule  of  water  under  favorable  conditions,  the  hydro- 
gen of  the  water  molecule  is  seized  upon  by  the  chlorin  to  form  chlor- 
hydric  acid  and  the  oxygen  is  set  free  in  the  nascent  state,  a  condition 
under  which  its  oxidizing  powers  are  exhibited  in  their  greatest  intensity. 
This  powerful  affinity  of  chlorin  for  hydrogen  enables  it  to  decompose 
many  other  hydrogen-containing  molecules  in  a  similar  manner,  form- 
ing chlorhydric  acid  and  destroying  the  identity  of  the  matter  acted 
upon. 

It  ha,s  been  shown  that  all  organic  compounds  which  are  the  products 
of  the  vital  processes  of  the  animal  body  contain  hydrogen  as  an  im- 
portant constituent.  This  applies  also  to  the  decomposition  products 
whose  presence  in  the  tubular  structure  of  the  dentin  is  the  cause  of 
tooth  discoloration. 

These   organic   stains   exhibit    the    pi-opcrty   of"  color   by    virtue   of 


542  DISCOLORED   TEETH  AND   THEIR   TREATMENT. 

certain  definite  conditions  of  molecular  composition  ;  hence,  if  cliloi'iii 
is  caused  to  act  upon  the  coloring  matter  which  causes  the  staininij^  of 
a  tooth,  by  seizing  upon  and  combining  with  the  liydrogen  of  the 
organic  pigment,  the  identity  of  the  compound  as  such  is  destroyed, 
and  its  characteristic  feature,  that  of  color,   is  lost. 

The  principle  here  outlined  is  involved  in  what  is  termed  the  direct 
action  of  chlorin  in  bleaching.  There  is,  however,  another  method  by 
which  chlorin  is  believed  to  act  as  a  bleacher  in  which  its  function  is 
indirect.  In  some  cases  it  has  been  observed  that  chlorin  fails  to  act 
except  in  the  presence  of  moisture,  and  the  rationale  of  this  is  that  the 
bleaching  under  such  conditions  is  effected  by  nascent  oxygen  liberated 
from  the  water  molecule  when  the  chlorin  combines  with  its  hydrogen 
to  form  chlorhydric  acid  ;  thus  :  CI  +  H,()  -=  2HC1  +  O.  That  such 
is  the  nature  of  the  process  in  many  cases  is  a  reasonable  deduction 
from  the  behavior  of  chlorin  under  analogous  conditions  where  it  acts 
indirectly  as  an  oxidizing  agent. 

"Whatever  may  be  the  exact  nature  of  its  ultimate  action,  it  is  to  be 
borne  in  mind  that  its  bleaching  effect  is  due  solely  to  the  alteration 
which  it  makes  in  the  composition  of  the  color  molecule,  and  that  it 
has  no  solvent  power  whatever  on  the  organic  matter  upon  which  it 
acts.  It  changes  its  characteristics,  but  does  not  remove  it  by  solution. 
It  should  be  also  noted  in  this  connection  that  the  chlorin  compounds 
of  most  of  the  metallic  elements,  especially  when  in  dilute  solution,  are 
almost  colorless  as  compared  with  many  of  the  other  metallic  com- 
pounds— the  oxids  and  sulfids  for  example.  Hence  it  is  that  where 
stains  owe  their  color  to  the  presence  of  certain  organic  compounds 
with  some  of  the  metals,  or  even  where  the  coloration  is  due  to  decom- 
position products  of  hemoglobin,  the  color  may  readily  be  discharged 
by  chlorin,  but  if  the  iron  chlorid  thus  produced  remains  in  the  tooth 
structure  it  is  gradually  decomposed  and  new  combinations  of  it  are 
liable  to  occur,  which  results  in  a  return  of  the  discoloration. 

All  tooth-bleaching  methods  should  aim  not  only  to  discharge  the 
color  by  suitable  chemical  means,  but  should  go  farther  than  this  and, 
as  far  as  it  may  be  possible  to  do  so,  remove  all  organic  debris  from  the 
tubules,  for  as  long  as  any  remains  the  tendency  to  a  return  of  the  dis- 
coloration is  always  a  ]iossible  and  indeed  probable  menace  to  the  com- 
plete and  permanent  success  of  the  operation. 

Where  the  tubular  contents  cannot  be  successfully  removed,  the 
tendency  to  a  return  of  discoloration  may  be  combated  by  hermetically 
sealing  the  tubular  orifices  with  an  impermeable  resinous  varnish  or 
permanently  coagulating  them.  This  feature  is  described  more  fully  in 
relation  to  the  details  of  the  bleaching  procedure. 

Teeth  Suitable  for  the  Bleaching  Operation. — In  deciding  upon 


TOOTH-BLEACHING— USE  OF  CHLORIX.  543 

the  advisability  of  attompting  the  bleaching  operation  in  any  given  case, 
the  general  conditions  which  determine  the  jndgnient  of  the  operator 
with  respect  to  all  dental  operations  should  govern  his  course. 

As  all  therapeutic  and  restorative  measures  in  dentistry  are  a  series 
of  compromises  Avith  disease  conditions  or  their  scquela%  it  is  the  duty 
of  the  operator  under  all  circumstances  to  capitulate  upon  the  basis  of 
greatest  advantage  to  the  patient.  Therefore  if  discoloration  of  a  tooth  is 
practically  the  only  factor  in  the  problem  presented  by  a  given  case, 
the  effort  should  be  made  to  restore  the  organ  to  its  normal  condition 
of  color.  The  same  rule  should  be  applied  to  all  cases  of  discolored 
teeth  in  which  structural  loss  by  caries  or  fracture  has  not  been  so  great 
as  to  preclude  a  satisfactory  restoration  by  proper  filling  or  replace- 
ment of  the  lost  structure  by  a  porcelain  inlay.  The  cases  in  which  it 
is  not  advisable  to  attempt  a  bleaching  operation  are  only  those  in  which 
loss  of  structure  is  so  extensive  as  to  require  a  crowning  operation. 

In  the  judgment  of  many  operators  it  is  considered  useless  to  at- 
tempt the  bleaching  of  any  teeth  excepting  the  incisors,  because  of  the 
difficulty  and  length  of  time  frequently  required  for  the  successful 
bleaching  of  canines,  bicuspids,  and  molars,  owing  to  the  thickness  of 
their  walls  and  the  consequent  depth  of  structure  requiring  treatment. 
It  is  also  held  to  be  useless  to  attempt  the  bleaching  of  teeth  which 
have  been  discolored  by  metallic  stains  throughout  their  structure. 
The  fallacv  of  such  a  view  is  self-evident  when  it  is  considered  that  if 
any  portion  of  the  dentinal  structure  of  a  discolored  tooth  is  amenable 
to  the  bleaching  treatment,  its  complete  restoration  is  simply  a  question  of 
continuance  or  repetition  of  the  operation  until  the  desired  end  is  attained. 

With  regard  to  discoloration  by  metallic  stains,  while  teeth  so  af- 
fected present  problems  of  great  complexity,  and  require  not  only 
special  study  but  the  application  of  special  methods  of  treatment  based 
upon  proper  recognition  of  the  chemical  relationships  involved  between 
the  nature  of  the  stain  and  that  of  the  agent  used  for  its  removal,  the 
attempt  should  be  made  in  justice  to  the  patient,  even  though  idtimate 
failure  result,  in  order  that  the  necessity  for  destruction  of  the  natural 
crown  for  the  purpose  of  its  replacement  by  an  artificial  substitute  may, 
if  possible,  be  postponed  for  as  long  a  ]ieriod  as  may  be  attainable. 

Preparation  of  the  Tooth  for  the  Operation  of  Bleaching. — Cer- 
tain general  details  are  necessary  to  be  observed  in  tlu^  jn-eparation  of 
teeth  for  the  bleaching  operation,  whatever  may  be  the  method  of  treat- 
ment employed. 

Appropriate  treatment  for  the  removal  of  all  se])tic  matter  from  the 
pulp  chamber  and  canal,  and  for  the  relief  of  any  existing  condition  of 
irritation  of  the  pericemental  membrane  and  tissues  of  the  apical  region, 
should  have  been  carried  out  and  the  tooth  brought  to  the  condition  in 


544  DISCOLORED    TEETH  AND   THEIR   TREATMENT. 

which  jxTinaiuMit  clo.sure  of  the  apical  ioraincn  of  the  root  may  l)c  safclv 
pci'foi'incd. 

The  rubber  dam  should  be  adjusted  with  especial  care  and  (»nly 
include  the  tooth  to  be  bleached.  If  two  adjoining  teeth  are  to  be 
bleached* they  may  both  be  isolated  by  the  dam,  but  in  no  case  should 
one  or  more  adjacent  normal  teeth  be  included  with  the  tooth  to  be 
bleached.  AVhilc  the  inclusion  of  teeth  adjacent  to  the  one  which  is  the 
subject  of  any  ordinary  dental  operation  is  in  nearly  all  cases  desirable^ 
there  are  good  reasons  why  such  a  plan  should  not  be  pursued  in  the 
bleaching  procedure.  The  chemicals  used  for  the  purpose  may  possibly 
have  some  disintegrating  or  solvent  action  u})on  the  enamel  structure, 
and  such  action,  should  it  occur,  should  be  confined  strictly  to  the  tooth 
undery-oiny;  treatment  and  held  within  the  limits  of  safety  bv  close 
observation  and  appropriate  treatment,  which  conditions  cannot  be  as 
thoroughly  controlled  and  the  process  as  satisfactorily  managed  when 
several  teeth  are  included  within  the  territory  of  operation. 

Furthermore,  as  nearly  all  of  the  bleaching  agents  used  or  those 
which  are  employed  as  adjuvants  in  the  process  have  a  more  or  less 
irritative  or  escharotic  effect  U])on  the  soft  tissues  of  the  mouth,  extra 
precautions  must  be  taken,  in  adjusting  the  dam,  against  leakage  at  its 
attachment  to  the  cervix  of  the  tooth.  As  the  chances  of  leakage  are 
greatly  niulti})lied  when  several  holes  are  punched  in  the  dam  for  ad- 
justment to  as  many  teeth,  it  is  for  this  reason  also  that  no  other  than 
the  tooth  to  be  treated  should  have  the  dam  adjusted  to  it. 

Su]iposing  the  tooth  to  be  an  u])per  incisor,  the  dam  should  be 
slipped  over  it  and  the  margin  of  rubber  encircling  the  cervix  should 
be  gently  carried  under  the  free  margin  of  the  gum  either  by  means  of  a 
small  flat  burnisher  of  suitable  angle  and  curvature,  or  by  means  of  a 
waxed  floss-silk  thread.  One  or  two  turns  of  a  ligature  should  then  be 
thrown  around  the  cervix  below  the  dam  to  hold  it  securely  in  place. 
The  dam  may  be  fixed  with  greater  security,  especially  as  against  any 
accidental  traction  made  u])on  it  during  the  operation,  by  fastening  it 
with  a  liMture  made  as  follows  and  thrown  around  its  cervix  : 

A  piece  of  waxed  ligature  silk  about  eighteen  inches  in  length  has 
a  large  knot  tied  at  about  its  middle  portion  by  making  six  or  eight 
turns  of  the  thread  loosely  around  the  end  of  the  index  finger  of  the 
left  hand.  Upon  withdrawing  the  finger  a  series  of  loops  are  had 
through  which  one  of  the  free  ends  of  the  thread  is  now  passed,  as 
in  making  the  first  half  of  a  flat  knot,  as  illustrated  in  Fig.  480. 
By  drawing  upon  the  free  ends  of  the  thread  until  all  of  the  loops 
are  closed  upon  themselves,  a  hard  knot  of  more  or  less  spheroidal 
shape  is  formed  about  midway  between  the  ends  of  the  ligature.  The 
ligature  so  prepared  is  placed  around  the  tooth  in  such  a  manner  that 


TOOTH-BLEACHING— USE  OF  CHLORIN.  645 

the  knot  as  described  shall  be  located  upon  and  at  the  middle  portion 
of  the  palatal  cervical  margin.  A  half  knot  is  then  made  by  tying  the 
ligature  in  front  so  that  it  shall  rest  directly  opposite  the  palatal  knot, 
viz.  at  the  middle  portion  of  the  labial  cervical  margin.  The  ligature 
is  drawn  into  fairly  close  contact  with  the  tooth,  and,  with  both  ends 
held  hrmly  in  the  left  hand  and  drawn  somewhat  tense,  the  portion 
encircling  the  tooth  is  firmly  but  gently  forced  up  against  the  rubber 

Fig.  480. 


dam  and  gingival  margin,  the  ligature  at  the  same  time  being  drawn 
tightly  until  the  anatomical  constriction  of  the  tooth  at  its  cervix  will 
serve  to  hold  it  from  slipping  downward,  especially  upon  the  palatal 
aspect  of  the  tooth. 

When  the  ligature  is  found  to  be  securely  placed  as  described,  the 
knot  upon  the  labial  aspect  is  completed  and  further  enlarged  in  bulk 
by  re-tying  the  thread  four  or  five  times.  The  free  ends  of  the  ligature 
should  then  be  cut  oif  close  to  the  knot.  As  an  additional  safeguard 
against  leakage  of  irritating  bleaching  agents  through  the  cervical 
attachment  of  the  dam,  and  out  upon  the  soft  tissues,  it  is  well  after 
making  the  tooth  perfectly  dry  to  paint  the  ligature  and  a  narrow  band 
of  its  adjacent  territory  with  chloro-percha,  which  will  effectually  prevent 
any  accident  from  leakage. 

The  placing  of  a  large  knot  upon  the  palatal  aspect  at  the  cervical 
margin  has  another  decided  advantage  in  that  it  not  only  holds  the  dam 
more  securely  against  slipping  downward,  but  holds  it  away  from  the 
palatal  surface,  which  is  ordinarily  the  point  of  entrance  to  the  pulp 
chamber  and  canals  in  these  cases.  The  point  of  canal  entrance  may, 
however,  be  through  an  approximal  cavity,  if  such  an  one  affords 
sufficient  access. 

The  canal  filling  in  all  cases  of  bleaching  without  exception  should 
be  gutta-percha.  No  other  material  used  for  canal  filling  possesses  the 
generally  desirable  qualities  needed  for  that  purpose  in  this  class  of 
cases.  The  extent  of  the  canal  filling  should  include  one-third,  or  at 
least  not  over  one-half,  of  the  distance  from  the  apex.  A  considerable 
portion  of  the  canal  beyond  the  level  of  the  gingival  margin  is  thus 
left  unfilled  in  order  that  the  coronal  end  of  the  root  may  be  bleached 
as  well  as  the  tooth  crown.  This  is  especially  necessary  where  more 
or  less  recession  of  the  gum  from  its  normal  attachment  has  occurred, 

35 


546  DISCOLORED   TEETH  AND   THEIR   TREATMENT. 

leaving  the  cervical  cementum  exposed  to  the  action  of  the  oral  flnids, 
food,  etc.,  Avhich  have  a  tendency  to  canse  discoloration  of  the  exposed 
root  tissue. 

The  root  being  filled  as  directed,  all  fillings  wherever  existent  in  the 
tooth  should  be  removed.  This  is  a  })r('liniinary  ])roceduro  which 
should  not  be  omitted  in  any  case,  but  where  any  bleaching  method  is 
used  which  involves  the  em])loynient  of  chlorin  as  the  active  agent  it 
becomes  imperatively  necessary  for  reasons  which  are  exjilaincd  in  con- 
nection with  the  description  of  the  chlorin  methods  (l)age  547).  Aside 
from  other  considerations,  the  removal  of  all  fillings  preparatory  to  the 
bleaching  operation  has  a  decided  value  in  facilitating  the  process  by  ex- 
posing an  increased  area  of  the  dentinal  structure  and  thereby  })ermit- 
ting  the  action  of  the  bleaching  agent  over  a  larger  territory  of  ingress. 

When  all  fillings  or  softened  tooth  structure  have  been  removed,  as 
well  as  all  septic  and  extraneous  matter  of  whatever  character,  by 
mechanical  process,  the  tooth  should  be  washed  thoroughly  with  dilute 
ammonia  water,  or  better  with  a  hot  solution  of  borax  in  distilled  water 
in  the  proportion  of  5j  to  fsj.  The  object  of  this  treatment  is  to  re- 
move by  saponification  and  solution  all  fatty  matters  which  may  obstruct 
the  ingress  of  the  bleaching  agent  into  the  dentinal  structure. 

In  nearly  all  cases  where  discoloration  has  occurred  from  a  decom- 
posed pulp  and  where  the  canals  and  pulp  chamber  have  been  left 
untreated,  there  will  be  observed,  on  opening  into  such  a  pulp 
chamber  for  the  first  time,  a  dark  layer  of  oily  or  greasy  material 
lining  its  walls.  The  thorough  removal  of  this  dark  layer  should 
be  cifccted  prior  to  any  attempt  at  bleaching,  as  it  ajipears  to  prevent 
the  ingress  of  the  bleaching  agent  into  the  dentinal  structure.  The 
most  satisfactory  method  for  removing  the  dark  greasy  layer  is  by  the 
use  of  suitable  instruments — either  properly  shaped  spoon  or  hoe  ex- 
cavators or  round  burs  in  the  engine.  The  thorough  removal  of  this 
layer  necessitates  free  access  to  the  pulp  chamber,  which  should  be 
as  a  general  rule  obtained  by  means  of  an  ample  opening  upon  the 
lingual  aspect  of  the  tooth  in  the  case  of  incisors,  and  through  the 
morsal  surface  in  bicuspids,  etc. 

Having  by  mechanical  means  and  through  the  agency  of  borax  or 
ammonia  and  hot  distilled  water  effected  a  thorough  cleansing  of  the 
interior  portion  of  the  tooth,  it  should  next  be  dried  to  the  extent  of 
having  all  superfluous  moisture  removed,  and  it  Avill  then  be  in  condi- 
tion for  the  application  of  whatever  method  of  bleaching  may  be  chosen 
for  the  particular  case  in  hand. 

Dr.  James  Truman's  Method. — This,  as  before  stated,  was  the  first 
method  successfully  employed  foi'  bleaching  teeth.  It  consists  in  liberat- 
ing chlorin  from  ordinary  chlorinated  lime  by  means  of  a  weak  acid 


TOOTH-BLEACHING— USE  OF  CHLOBIN.  547 

ill  the  pulp  chamber  of  the  tooth.  Any  acid  will  effect  the  liberation  of 
chlorin  from  the  bleaching  powder,  but  acetic,  tartaric,  or  oxalic  are 
generally  used.  Care  must  be  observed  in  selecting  a  good  quality  of 
bleaching  powder,  as  that  substance  rapidly  undergoes  decomposition 
spontaneously,  especially  in  a  moist  atmosphere.  Good  chlorinated  lime 
is  a  dry  powder  having  a  strong  odor  of  chlorin.  If  it  is  moist  or  pasty 
aiid  has  but  a  feeble  odor  it  should  be  rejected  as  worthless.  Brands 
of  bleaching  powder  dispensed  in  metallic  packages  should  not  be  used, 
as  they  are  invariably  contaminated  with  metallic  chlorids  due  to  the 
slow  action  of  the  contents  upon  the  containing  package.  This  is  par- 
ticularly the  case  where  sheet-iron  boxes  are  used.  The  return  of  dis- 
coloration in  many  cases  after  bleaching  by  the  Truman  method  is 
undoubtedly  due  to  the  use  of  bleaching  powder  so  contaminated. 
The  powder  dispensed  in  glass  bottles  or  in  paraffined  paper  cartons 
is  more  reliable. 

Its  application  to  the  tooth  may  be  effected  in  several  ways  : 

(a)  By  packing  the  dry  powder  in  the  pulp  chamber  and  then  moist- 
ening the  latter  with  the  acid  ; 

(b)  By  mixing  the  powder  with  sufficient  distilled  M'ater  to  make  a 
coherent  mass  which  is  more  easily  manipulated,  then  packing  it  in  the 
pulp  chamber  and  applying  the  acid  ; 

{(')  By  first  moistening  the  interior  of  the  tooth  with  the  acid,  next 
dipping  the  instrument  into  the  powder  and  then  into  the  acid,  each 
time  carrying  the  mixed  materials  into  the  tooth  until  the  desired 
change  of  color  is  produced. 

Probably  the  most  satisfactory  method  is  to  pack  the  dry  powder 
into  the  tooth  and  apply  the  acid  to  it,  after  which  immediately  seal  the 
cavity  with  a  single  pellet  of  gutta-percha.  By  using  a  50  per  cent, 
solution  of  acetic  acid  the  evolution  of  chlorin  will  take  place  with  a 
satisfactory  degree  of  uniformity,  and  not  so  rapidly  as  to  interfere  with 
its  penetration  throughout  the  discolored  tubular  structure  of  the  dentin. 
The  bleaching  mass  may  be  sealed  in  place  by  means  of  oxy phosphate 
of  zinc  if  desired,  but  it  is  usually  unnecessary  to  use  anything  other 
than  gutta-percha  or  one  of  the  soft  temporary  stopping  materials  for 
this  purpose. 

The  case  may  be  dismissed  for  one  or  two  days  and  the  treatment  as 
outlined  repeated  at  similar  intervals  until  the  tooth  is  restored  to 
normal  color. 

The  instruments  used  in  connection  with  this  jiroccss  should  be  of 
vulcanite,  bone,  ivory  or  wood.  Upon  no  consideration  should  steel, 
gold,  or  platinum  instruments  be  used,  as  chlorin  acts  directly  upon 
each  of  these  metals,  forming  soluble  chlorids  which  if  carried  into  the 
tooth  structure  will  give  rise  to  a  permanent  staining  of  most  intract- 


548  DISCOLORED   TEETH  AND  THEIR  TREATMENT. 

jiblc  character.  The  only  metals  Avhich  may  be  safely  used  in  connec- 
tion Avith  any  chlorin  ])rocess  of  bleaching  are  zinc  and  aluminum, 
the  chlorids  of  which  arc  colorless.  Aluminum  instruments  for  the 
purpose  may  be  quickly  improvised  out  of  wire  or  heavy  plate.  Gold 
instruments  have  been  recommended,  but  they  are  open  to  the  very 
(2:rave  ol^jection  of  forming  a  chlorid  by  direct  combination  with  chlorin, 
which  salt  is  one  of  the  most  important  staining  media  known  to  the 
histologist ;  as  a  matter  of  fact  the  writer  has  seen  several  cases 
where  a  permanent  ])urple  staining  of  the  tooth  has  resulted  from 
neglect  to  remove  gold  fillings  before  applying  the  chlorin  method  of 
bleaching,  and  there  is  certainly  no  reason  why  the  same  result  should 
not  follow  the  using  of  gold  instruments  in  the  same  connection. 

When  the  tooth  has  been  restored  to  its  proper  color  it  should  be 
thoroughly  washed  with  very  hot  distilled  water,  dried  out  with  bibu- 
lous paper  and  thoroughly  desiccated  with  a  current  of  dry  hot  air, 
after  which  the  canals,  Jiulp  chamber,  and  cavities  should  be  filled  with 
oxychlorid  of  zinc. 

The  final  filling  of  the  cavities  of  entrance  and  of  decay  should  be 
postponed  until  by  a  lapse  of  considerable  time  the  permanence  of  the 
operation  has  been  established.  This  probationary  period  may  with 
advantage  be  prolonged  to  four  or  six  months. 

The  final  washing  of  the  tooth  with  hot  distilled  water  previous  to 
the  insertion  of  the  oxychlorid  of  zinc  filling  is  a  feature  of  the  opera- 
tion which  requires  special  care  and  attention.  As  left  after  the  appli- 
cation of  the  bleaching  agent,  the  pulp  chamber  and  canals  and  denti- 
nal structure  are  filled  with  free  chlorin  in  solution,  calcium  acetate,  or 
other  salt  of  calcium  depending  upon  the  nature  of  the  acid  used  in 
the  process,  and  some  undecomposed  bleaching  powder.  These  sub- 
stances should  be  thoroughly  removed  by  the  hot-water  douche.  At 
least  a  pint  of  water  should  be  strongly  injected  into  the  interior  of  the 
tooth  l)y  means  of  a  large  bulb  syringe,  before  the  dam  is  removed.  A 
towel  held  in  close  proximity  to  the  tooth  will  catch  the  water  as  it  re- 
turns from  the  tooth  and  protect  the  clothing  of  the  jxatient.  Distilled 
water  should  in  all  cases  be  used  for  this  irrigating  douche,  as  river 
water  and  many  other  specimens  of  water  from  natural  sources  contain 
iron  in  solution,  which  could  readily  become  a  contaminating  factor 
leading  to  subsequent  return  of  discoloration. 

Oxychlorid  of  zinc  is  selected  as  the  permanent  filling  for  the  pulp 
chamber  for  the  reason  that  it  is  necessary  to  so  act  upon  the  bleached 
organic  residuum  in  the  tubular  structure  as  to  prevent  any  alteration 
of  its  character  which  may  result  in  the  production  of  a  subsequent 
coloration.  Zinc  chlorid  possesses  the  property  of  converting  many 
organic  substances  into  unalterable  compounds  by  its  coagulant  action, 


TOOTH-BLEACHING— USE  OF  CHLORIN.  549 

thus  tanning  or  mummifying  animal  tissue  and  preserving  it  indefi- 
nitely. A  mass  of  oxychlorid  of  zinc,  before  it  sets,  i.  e.  before  chemical 
combination  takes  place  between  the  oxid-of-zinc  powder  and  the  zinc 
chlorid  liquid,  is  functionally  free  zinc  chlorid — and  as  a  matter  of  fact 
the  properties  of  zinc  chlorid  are  manifested  by  such  a  mass  for  a  con- 
sideralile  period  of  time  after  the  mass  has  apparently  set.  When 
introduced  into  the  pulp  chamber  and  canal,  its  action  upon  the  organic 
debris  in  the  tubuli  is  as  stated,  and  the  material,  if  the  operation  has 
been  successfully  performed,  is  effectually  prevented  from  further  alter- 
ation, upon  which  condition  the  permanence  of  the  operation  depends. 

Another  method  for  preventing  subsequent  alteration  of  the  bleached 
organic  debris  in  the  tubular  structure  is  to  thoroughly  desiccate  the 
tooth  by  means  of  the  hot-air  blast  and  saturate  the  dentin  with  some 
insoluble  resinous  varnish,  such  as  copal  ether  varnish,  or  what  is  still 
better  the  solution  of  trinitrocellulose  in  methyl  alcohol,  known  in  com- 
merce as  "  kristaline  "  or  at  the  dental  depots  as  "  cavitine."  The 
pulp  chamber  and  canals  may  then  be  filled  with  any  suitable  filling. 

As  between  the  oxychlorid  of  zinc  filling  and  the  varnish  lining  the 
choice  in  general  should  be  of  the  former.  The  varnish  lining  is  adapt- 
able more  especially  to  cases  of  long  standing  where  complete  liquefac- 
tion of  the  tubular  contents  has  left  them  practically  empty,  and  where 
as  a  consequence  there  is  nothing  upon  which  zinc  chlorid  can  exert  its 
coao'ulatino'  effect. 

other  Chlorin  Methods. — The  solution  of  chlorinated  soda  known 
as  Labarraque's  solution,  or  Liquor  sodte  chloratje  U.  S.  P.,  may  be 
applied  to  the  previously  desiccated  tooth  structure  until  the  dentin 
is  saturated  with  the  solution,  after  which  an  application  of  a  dilute 
acid  is  made  which  liberates  chlorin.  The  chemical  principles  in- 
volved are  exactly  analogous  to  those  upon  which  the  method  with 
bleaching  powder  depends,  the  only  difference  being  that  the  source 
of  the  active  agent,  chlorin,  is  in  one  case  its  calcium  compound,  which 
is  a  dry  powder,  and  in  the  second  case  the  analogous  soluble  sodium 
compound  of  chlorin  is  the  material  from  which  the  active  agent  is 
evolved. 

The  precautions  necessary  to  be  observed  are  exactly  the  same  as 
those  required  in  Truman's  method  already  described.  The  results 
obtained  by  this  process  are  not  as  thorough  or  as  satisfactory  as  by  the 
Truman  method. 

Chlorin  per  se  has  been  used  for  tooth-bleaching,  and  was  the  basis 
of  a  method  devised  by  Dr.  E.  P.  Wright  of  Richmond,  Va. 

"Wright's  method  involved  the  use  of  a  complicated  apparatus  by 
which  a  glass  vessel  of  about  a  half-liter  capacity,  and  filled  with  chlorin 
previously  prepared  in  the  laboratory,  was  connected  by  means  of  a 


550  DISCOLORED  TEETH  AND   THEIR   TREATMENT. 

doubly  perforated  rubber  stopper  and  two  pieces  of  rubber  tubing  with 
a  glass  adapter,  around  the  open  end  of  which  was  tied  the  rubber  dam 
encirclinj^  the  tooth  to  be  operated  upon.  About  midway  of  the  lenj:;th 
of  one  of  tlie  rubber  tubes  connecting  th(>  chlorin  res(>rvoir  with  tlie 
rubber  dam  Mas  interposed  an  ordinary  syringe  bull),  so  arranged  with 
hard-rubber  valves  that  by  rei)eatedly  c()m])r(>ssing  and  relaxing  it  the 
chlorin  would  be  drawn  from  the  reservoir  and  injected  through  a  glass 
dcliverv  j(»t  into  the  pulp  (;hamber.  Return  of  the  gas  to  the  reservoir 
was  provided  for  by  the  second  piece  of  rubber  tubing  first  alluded  to. 
In  this  way  a  continuous  jet  of  chlorin  was  thrown  into  and  about  the 
tooth,  which,  by  means  of  the  rubber  dam,  was  placed  in  a  close  cham- 
hvY  forming  a  part  of  the  apparatus  ;  none  of  the  gas  could  escape  into 
the  surrounding  atmosphere.  The  complexity  of  the  apparatus  was 
a  formidable  obstacle  to  the  general  use  of  the  method  and  it  was 
abandoned,  though  the  results  were  in  many  cases  very  satisfactory. 

The  Dioxid  Bleaching  Methods. 

Bleaching-  by  Means  of  the  Dioxid  of  Hydrog-en  and  the  Dioxid 
of  Sodium. — The  commercial  introduction  of  solutions  of  hydrogen 
dioxid  marked  a  new  era  in  the  operation  of  bleaching  discolored  teeth. 
The  bleaching  property  of  hydrogen  dioxid  had  been  known  to  chemists 
for  many  years,  but  the  application  of  this  property  to  tooth-bleaching 
dates  from  the  medicinal  use  of  hydrogen  dioxid  solutions  for  the  treat- 
ment of  purulent  conditions  of  the  pulp  canal  and  about  the  roots  of 
teeth.  When  applied  in  the  canals  of  discolored  and  infected  teeth  it 
was  observed  that  a  noticeable  bleaching  of  the  discolored  structure 
resulted.  The  hint  thus  given  was  further  studied  until  it  was  found 
that  under  proper  conditions  the  whole  structure  of  a  discolored  tooth 
might  be  successfully  restored  to  normal  color. 

The  earlier  preparations  were  found  to  be  lacking  in  strength  ; 
aqueous  solutions  containing  more  than  3  or  4  per  cent,  of  absolute 
hydrogen  dioxid  were  found  to  be  too  unstable  to  keep  for  any  length 
of  time,  and  hence  were  unreliable.  The  problem  of  securing  a  stable 
high-percentage  solution  of  the  dioxid  was  solved  by  using  ether  as  a 
menstruum,  and  the  25  per  cent,  solution  of  hydrogen  dioxid  made  by 
INIcKesson  &  Robbins  of  New  York  and  sold  as  "■  caustic  pyrozone  " 
is  now  generally  used  where  hydrogen  dioxid  is  employed  as  a  bleaching 
agent  in  connection  with  discolored  tooth  structure. 

Hydrogen  dioxid,  H.O,,,  belongs  to  the  class  of  "  oxidizing  bleach- 
ers," and  owes  its  activity  in  this  respect  to  the  Aveak  state  of  chemical 
combination  in  which  one  of  its  atoms  of  oxygen  is  bound  to  the  water 
molecule.  Many  substances  serve  to  disrupt  the  compound  and  liber- 
ate one  of  its  oxygen  atoms.     In  contact  w^th   pus,  blood,  inspissated 


BLEACHING  BY  HYDROGEN  DIOXID.  551 

mucus,  albumin,  and  in  fact  almost  every  kind  of  dead  organic  matter, 
its  decomposition  takes  place,  evolving  oxygen  and  decomposing  the 
organic  matter  either  wholly  or  in  part.  Hydrogen  dioxid  does  not 
bleach  all  of  the  decomposition-products  of  hemoglobin  with  equal 
facility.  It  quickly  removes  the  pink  discoloration  following  the  initial 
extravasation  of  hemoglobin  into  the  dentin,  but  when  the  brown  stage 
has  been  reached  indicative  of  the  formation  of  hematin  its  action  is  but 
slight.  Later,  however,  it  bleaches  more  readily.  The  refractory 
nature  of  hematin  with  respect  to  hydrogen  dioxid  has  been  experimen- 
tally tested  upon  the  substance  out  of  the  mouth. 

In  bleaching  discolored  teeth  with  hydrogen  dioxid  the  ethereal  25 
per  cent,  solution  known  as  pyrozone  is  directly  applied  to  the  internal 
portions  of  the  tooth  upon  small  pledgets  of  cotton  or  cotton  wisps 
rolled  upon  a  fine  flexible  canal  instrument.  After  each  application 
the  ethereal  menstruum  is  evaporated  by  blasts  of  warmed  air  from  a 
hot-air  syringe,  and  the  applications  similarly  made  are  repeated  until 
the  desired  effect  is  produced.  It  has  been  found  in  practice  that  more 
rapid  and  permanent  effects  are  produced  when  the  pyrozone  solution 
is  rendered  alkaline.  This  may  be  readily  done  by  the  addition  of  a 
few  drops  of  liquor  ammonite  fortior  or  by  a  solution  of  one  of  the 
caustic  alkalies,  e.  g.  sodium  or  potassium  hydroxid  or  sodium  dioxid, 
A  very  satisfactory  method  of  securing  the  alkaline  effect  in  this  pro- 
cess is  that  suggested  by  Dr.  D.  N.  INIcQuillen,  His  method  is  to 
first  treat  the  pulp  chamber  and  canals  with  applications  of  Schreier's 
Kalium-natrium  preparation  and  after  the  debris  from  its  action  has 
been  mechanically  removed  with  instruments  and  cotton  twists,  with- 
out washing  the  canal,  an  application  of  pyrozone  is  made.  The 
bleaching  action  follows  with  great  rapidity,  and  has  apparently  greater 
permanence  than  where  the  pyrozone  is  used  alone.  In  cases  where 
the  action  proceeds  very  slo^vly,  for  example  when  at  the  end  of  a  thirtv 
minutes'  continuous  treatment  the  bleaching  is  not  complete,  it  is  Avell 
to  seal  an  application  of  pyrozone  upon  cotton  in  the  canal  and  allow  it 
to  remain  for  twenty-four  hours,  when  a  second  treatment  will  usually 
complete  the  operation. 

In  this  as  in  all  bleaching  operations  it  is  advisable  to  fill  the  tooth 
temporarily  with  some  easily  removable  filling  in  order  to  test  the  per- 
manence of  the  operation,  and  after  the  lapse  of  a  reasonable  time  if 
there  is  no  tendency  to  a  return  of  the  discoloration  the  canals  and 
cavity  may  be  permanently  filled. 

Dr.  Harlan's  method,  consists  in  acting  upon  hydrogen  dioxid  by 
aluminum  chlorid.  The  aluminum  salt  is  packed  in  the  cavity  and 
moistened  with  the  dioxid.  The  technique  of  the  procedure  is  the 
same  as  for  the  methods  already  described.     This  process  was  origin- 


552  DISCOLORED   TEETH  AND   THEIR  TREATMENT. 

ally  classified  with  the  chlorin  methods,  as  the  decomposition  was  sup- 
posed to  take  place  according  to  the  following  equation  : 

Allele  +  3HA  =  Al  A  +  SH^O  +  6C1. 

Experimental  study  of  the  reaction  between  aluminum  chlorid  and 
hydrogen  dioxid  by  the  writer  developed  the  fact  that  oxygen  and  not 
chlorin  was  given  off,  and  that  the  aluminum  chlorid  was  unaltered 
during  the  process.  Hence  it  was  discovered  that  the  reaction  was 
simply  due  to  a  catalytic  action  of  the  aluminum  salt  (a  property 
which  in  this  relation  it  shares  in  common  with  many  other  metallic 
salts),  whereby  nascent  oxygen  is  liberated  from  the  hydrogen  dioxid. 
The  process,  therefore,  has  no  greater  value  than  those  in  which  hydro- 
gen dioxid  is  directly  applied.  The  aluminum  chlorid  being  an  active 
coagulant  is  contraindicated  as  a  factor  in  tlic  bleaching  process  until 
a  point  has  been  reached  where  a  coagulant  is  needed  as  a  fixative  after 
the  bleaching  has  been  effected. 

The  Sodium  Dioxid  Method. — Sodium  dioxid,  NajO^,  is  the  chem- 
ical analogue  of  hydrogen  dioxid,  and  like  the  latter  is  characterized 
by  the  readiness  with  which  it  parts  with  its  atom  of  loosely  com- 
bined oxygen  under  similar  circumstances.  The  essential  difference  in 
its  properties  is  the  character  of  its  by-product  after  its  decomposition 
has  taken  place.  Itself  a  strong  caustic  alkali,  it  still  retains  its  alka- 
line and  caustic  properties  after  the  loss  of  one  of  its  atoms  of  oxygen, 
becoming  NagO,  which  in  combination  with  water  is  ordinary  sodium 
hydroxid  or  caustic  soda.  This  substance  as  well  as  the  sodium  dioxid 
has  not  only  a  saponifying  property  for  all  of  the  vegetable  and  animal 
oils  and  fats,  but  also  a  solvent  action  upon  animal  tissue.  This  property 
is  of  great  value  in  removing  from  the  dentin  structure  all  of  the  con- 
tained organic  matter,  whether  normal  or  in  a  state  of  decomposition. 
Having  the  oxidizing  and  consequently  the  bleaching  quality  in  addi- 
tion to  its  solvent  and  saponifying  properties  it  is,  therefore,  one  of  the 
most  valuable  bleaching  and  detergent  agents  at  our  command.  The 
substance  is  dispensed  as  a  yellowish  white  powder  in  tin  cans  or 
glass  bottles  hermetically  sealed,  as  it  is  very  hygroscopic  and  after 
twenty-four  hours'  exposure  to  moist  air  absorbs  nearly  its  own  weight 
of  water ;  it  also  loses  much  of  its  activity. 

For  use  as  a  bleaching  agent  it  is  applied  to  the  dentin  in  saturated 
solution.  In  making  the  solution  especial  care  is  necessary  in  order  to 
avoid  elevation  of  temperature,  by  reason  of  the  energy  with  which  it 
enters  into  combination  with  the  water.  If  the  solution  is  allowed 
to  become  heated  in  the  making,  decomposition  of  the  compound  with 
loss  of  oxygen  occurs  and  its  bleaching   power   is   destroyed.      The 


BLEACHING  BY  SODIUM  DIOXID.  55S 

solution  is  best  made  by  pouring  into  a  small  beaker  of  about  one 
ounce  capacity  about  two  drachms  of  distilled  water,  and  immersing  the 
beaker  in  a  larger  vessel  or  dish  containing  ice-water  or  pounded  ice. 
The  can  containing  the  dioxid  powder  should  then  have  its  lid  per- 
forated with  a  number  of  small  holes  similar  to  the  lid  of  a  pepper 
caster,  and  the  powder  be  slowly  dusted  into  the  distilled  water  in  the 
small  beaker ;  or  the  powder  may  be  gradually  dropped  into  the  water 
by  tapping  it  from  the  point  of  a  knife  or  spatula.  The  powder  is 
added  to  the  water  until  the  solution  assumes  a  semi-opaque  appearance, 
indicating  the  point  of  saturation.  On  removing  the  beaker  from  the 
cooling  mixture,  the  dioxid  solution  will  in  a  few  minutes  assume  a 
transparent,  straw-colored  appearance   and  is  ready  for  use. 

The  applications  are  to  be  made  similarly  to  the  hydrogen  dioxid 
applications,  but  upon  asbestos  fiber  instead  of  cotton,  as  the  latter  is 
acted  upon  by  the  sodium  dioxid  and  converted  into  a  glue-like  mate- 
rial, amyloid,  which  is  difficult  to  remove  and  interferes  with  the  suc- 
cess of  the  operation. 

After  the  dentin,  which  should  have  been  previously  desiccated,  is 
thoroughly  saturated  with  the  dioxid  solution  an  application  of  10  per 
cent,  sulfuric  acid  should  be  made,  which  neutralizes  the  strong  alkali^ 
forming  sodium  sulfate  and  hydrogen  dioxid,  thus  : 

XaP^  +  H,SO,  =  NagSO,  +  H2O2. 

The  reaction  is  usually  attended  with  some  effervescence,  which  taking 
place  in  the  tubular  structure  of  the  dentin,  mechanically  forces  out  its 
contents  and  thus  exerts  a  detergent  action  upon  it.  The  tooth  should 
now  be  washed  with  hot  distilled  water  in  copious  quantity  and  the 
dioxid  application  repeated,  omitting  the  subsequent  treatment  with 
acid  but  washing  again  thoroughly  with  the  hot  water. 

Sodium  dioxid  solution,  as  prepared  for  bleaching,  may  be  applied 
to  the  pulp  chamber  and  root  canal  without  the  preliminary  treatment 
required  where  other  bleaching  agents  are  employed.  It  is  without 
harmful  irritative  action  upon  the  apical  tissues  unless  used  in  excess 
or  foi'ccd  through  tlie  foramen  by  careless  manipulation.  It  is  a  power- 
ful germicide  and  disinfectant,  and  therefore  peculiarly  suited  to  the 
treatment  of  putrescent  cases,  which  by  its  action  are  rendered  sterile 
and  aseptic  as  well  as  bleached  at  one  operation.  Its  saponifying  and 
solvent  properties  completely  remove  the  greasy  dark  layer  of  decom- 
posed material  which  is  found  lining  the  pulp  chamber  and  canals 
alluded  to  on  page  546,  so  that  the  use  of  the  sodium  dioxid  method 
makes  unnecessary  the  application  of  borax  or  ammonia  for  its  removal 
as  a  preliminary.     When  used  for  its  sterilizing  property  the  foramen 


554  DISCOLORED  TEETH  AND   THEIR   TREATMENT. 

shoiikl  be  allowed  to  remain  unsealed  until  after  the  bleaching  operation 
has  been  completed.  It  sometimes  happens  that  the  improvement  in 
color  following  the  application  of  the  dioxid  methods  is  only  partial 
and  the  result  falls  short  of  restoration  to  normal ;  or,  in  other  words, 
the  bleaching  reaches  a  certain  point  beyond  which  the  color  resists  the 
further  action  of  the  bleaching  agent.  In  such  cases  the  decomposition 
of  tlie  color  molecule  has  probably  resulted  in  the  formation  of  iron 
oxid  as  an  end-product.  In  practice  this  residual  discoloration  can 
generally  be  removed  by  treatment  with  oxalic  acid.  A  small  crystal 
is  to  be  sealed  in  the  moist  pulp  chamber  for  twenty-four  liours, 
and  afterward  washed  out  with  a  copious  irrigation  of  hot  distilled 
water. 

The  sodium  dioxid  method  removes  more  completely  than  any 
other  the  tubular  contents,  and  the  result  is  unique  from  the  fact 
that  not  only  is  the  tooth  restored  to  normal  color  but  to  normal 
translucency ;  the  opaque  white  effect  resulting  from  other  methods 
of  bleaching  is  due  to  the  bleached  organic  debris  remaining  in  the 
tubuli,  but  by  the  solvent  action  of  the  strong  caustic  alkali  this  is 
removed.  The  final  treatment  of  the  tooth  is  the  same  in  this  as  in 
other  methods,  though  the  dentin  should  be  desiccated  and  saturated 
as  thoroughly  as  possible  with  an  unalterable  varnish  before  the  final 
filling  is  inserted. 

The  Sulfurous  Acid  Method. — Reference  has  already  been  made 
to  sulfurous  acid  as  the  single  example  of  the  reducing  tyjje  of  bleach- 
ing agent.  Its  activity  is  due  to  its  affinity  for  oxygen,  and  it  bleaches 
by  seizing  upon  and  combining  with  that  element  of  the  color  molecule, 
thus  destroying  its  identity  and  consequently  its  color.  Attempts  have 
been  made  to  utilize  the  bleaching  property  of  sulfurous  acid  in  the 
treatment  of  discolored  teeth  by  direct  applications  of  the  solution  of  the 
gas  in  water  and  by  igniting  small  quantities  of  sulfur  in  the  root  canal 
by  means  of  the  electro-cautery  wire.  Those  methods  have,  however, 
proved  inefficient.  The  gas  may  be  successfully  used  in  bleaching  teeth 
by  evolving  it  from  its  compounds  placed  in  the  cavity  and  root  canal 
in  a  manner  analogous  to  that  employed  in  the  Truman  chlorin  process 
already  described.  For  this  purpose  the  writer's  method  may  be  con- 
veniently employed  :  100  grains  of  sodium  sulfite  and  70  grains  of 
boric  acid  are  separately  desiccated  and  afterward  ground  together  in  a 
warm  dry  mortar.  The  powder  is  then  to  be  transferred  to  a  tightly 
stoppered  bottle.  For  bleaching  purposes  the  powder  is  packed  into  the 
root  canal  and  cavity  of  the  tooth,  and  then  moistened  with  a  drop  of 
water  and  the  cavity  immediately  closed  as  tightly  as  possible  with  a 
stopping  of  gutta-percha  previously  prepared  and  warmed.     A  reaction 


CATAPHORIC  BLEACHING   OF  TEETH.  555 

ensues  between  the  boric  acid  and  sodium  sulfite  whereby  sulfurous 
acid  is  liberated,  thus : 

2H3BO3  -f  3Xa,S03  =  2Xa3B03  +  3H,0  +3SO2. 

The  process  is  eiFective  in  many  cases  where  the  chlorin  methods  have 
failed,  but  is  slow  in  its  action  and  is  largely  superseded  by  the  dioxid- 
of-hydrogen  and  dioxid-of-sodium  methods. 

Cataphoric  Bleaching  of  Teeth. 

Since  the  revival  of  interest  in  cataphoresis  and  its  application  to 
dental  operations  its  possibilities  as  an  adjuvant  in  the  tooth-bleaching 
process  are  being  investigated  with  much  promise  of  valuable  results. 
It  has  been  found  that  aqueous  solutions  of  hydrogen  dioxid  may  be  car- 
ried into  the  dentinal  structure  with  great  ease  by  the  cataphoric  action 
of  the  continuous  current.  The  appliances  necessary  for  tooth-bleaching 
operations  by  this  means  are  practically  the  same  as  those  required  in  the 
treatment  of  hypersensitive  dentin,  and  are  detailed  at  length  in  the 
chapter  dealing  with  that  subject  (page  189).  The  resistance  oifered  by 
the  hard  structures  of  the  tooth  is  much  greater  after  loss  of  the  tooth 
pulp,  requiring  a  much  higher  voltage  pressure  to  drive  the  bleaching 
agent  into  the  tissue.  While  in  some  cases  25  to  30  volts  will  be  all 
that  is  necessary,  some  cases  will  require  as  high  as  60  volts  to  carry 
1.5  milliamperes  of  current  through  the  dentin.  The  ethereal  solution 
of  hydrogen  dioxid  has  been  found  to  oppose  too  great  resistance  to 
the  current,  but  the  aqueous  solution  containing  a  slight  addition  of 
some  salt  to  increase  its  conductivity  is  entirely  manageable. 

A  25  per  cent,  aqueous  solution  of  hydrogen  dioxid  may  be  quickly 
made  by  shaking  together  in  a  test  tube  one  volume  of  water  and  two 
volumes  of  25  per  cent,  pyrozone.  The  H^O^  dissolves  in  the  water, 
and  the  ether  of  the  pyrozone  may  be  removed  by  pouring  the  mixture 
into  a  small  evaporating  dish  of  porcelain  or  glass  and  gently  heating  it 
over  a  water  batli  until  all  of  the  ether  has  evaporated.  The  addition 
of  a  small  quantity  of  sodium  acetate  or  sulfate  will  greatly  diminish 
the  resistance  of  the  solution  to  the  passage  of  the  current. 

With  the  tooth  isolated  by  the  rubber  dam  and  having  received  the 
treatment  preliminary  to  bleaching,  as  already  described  in  detail,  the 
aqueous  solution  of  H^O,  is  dropped  upon  cotton  within  the  tooth 
cavity  and  a  platinum  needle  anode  is  applied  in  contact  with  it. 
The  cathode  may  be  a  sponge  electrode  moistened  with  salt  solution  and 
held  in  the  hand  or  applied  to  the  cheek  or  neck.  The  hand,  however, 
is  preferable  because  of  the  amount  of  voltage  required  in  the  operation. 
Great  care  must  be  exercised  that  the  external  surfaces  of  the  tooth  are 


55G  DISCOLORED   TEETH  AND  THEIR  TREATMENT. 

kept  dry  so  that  short-circuiting  of  the  current  may  not  take  place.  In 
some  cases  a  more  rapid  effect  is  obtained  by  making  contact  of  the 
cathode  pole  through  a  needle  electrode  upon  the  external  surface  of  the 
tooth,  and  with  the  anode  applied  to  the  pyrozone  solution  on  cotton 
within  the  tooth.  The  cotton  must  at  all  times  be  kept  wet  with  the 
solution. 

The  arrangement  of  the  electrical  terminals  with  respect  to  the 
bleaching  operation  is  both  theoretically  and  practically  correct  as  de- 
scribed, viz.  the  flow  of  current  should  be  from  the  anode  point  through 
the  bleaching  solution  and  tooth  and  the  body  of  the  patient  to  the 
cathode.  In  practice  it  has  been  found  in  some  cases  which  have  failed 
to  bleach  with  the  elements  arranged  in  the  series  as  stated,  that  upon 
reversing  the  poles  and  direction  of  current  flow  the  bleaching  has 
rapidly  followed.  The  explanation  of  this  apparent  paradox  is  that 
by  the  application  in  normal  order  H2O2  M'^as  first  carried  into  the 
tubular  structure,  and  the  reversal  of  the  current  has  acted  upon  the 
tubular  contents  now  saturated  with  the  dioxid,  and  by  its  propulsive 
as  well  as  electrolytic  effect  removed  the  pigmentary  matter  pulpward 
from  the  tubuli.  Bleaching  with  reversed  poles  would  be  impossible 
without  previous  saturation  of  the  dentin  by  the  dioxid  solution. 

Dr.  M.  AV.  Holliup-sworth  has  devised  an  ingenious  anode  for  feed- 
ing  the  bleaching  solution  or  other  medicament  into  the  cavity  as  de- 
sired.    The  instrument  (Fig.  154)  is  described  in  Chapter  VII. 

Another  device  by  Dr.  Hollingsworth  is  of  especial  value,  as  it 
makes  possible  the  enveloping  of  the  entire  tooth  with  the  bleaching 
fluid  in  which  it  is  immersed  as  in  a  bath.     The  appliance  is  shown  in 

Fig.  481. 


Dr.  Hollingsworth's  device  for  applying  the  bleaching  agent  to  the  tooth. 

situ  in  Fig.  481,  and  consists  of  a  thin  vulcanized  caoutchouc  bulb 
shaped  like  the  bulb  of  a  medicine  dropper.  Through  a  perforation 
at  its  rounded  end  made  with  the  ordinary  rubber  dam  punch,  the 
tooth  is  slipped  by  mounting  the  bulb  on  the  applicator  (Fig.  482),  and 


CATAPHORIC  BLEACHING   OF  TEETH. 


557 


forcing  it  over  the  tooth  as  though  it  were  a  rubber  dam.    A  glass  tube 

Fig.  482. 


is  then  attached  to  the  open  end  of  the  l)ulb,  and  to  the  glass  tube  is 
connected  a  spiral  platinum  wire  electrode  (Fig.  483).    Before  the  elec- 


FiG.  48.3. 


Tube  electrode. 


Irode  is  attached  the  bulb  and  glass  tube  are  completely  filled  with  the 
aqueous  pyrozone  solution  by  means  of  a  duplex  syringe  (Fig,  484),  the 


Fig.  484. 


Duplex  syringe. 


lower  and  larger  bulb  of  which  exhausts  the  contained  air  in  the  appa- 
ratus and  the  smaller  thumb  bulb  injects  the  bleaching  solution  into  the 
exhausted  apparatus.     Connection  is  now  made  with  the  source  of  cur- 


558  DISCOLORED   TEETH  AND  THEIR   TREATMENT. 

rent  as  usual,  and  the  bleaching  is  very  rajiidly  effected.  Dr.  Hol- 
lingsworth  recommends  the  addition  of  about  1  j)er  cent,  of  zinc  sulfate 
to  tlie  aqueous  pyrozone  solution,  which  not  only  diminislies  the  resist- 
ance to  the  ])assa_i>:e  of  the  current,  but  has  a  coagiilating  effect  u])on 
the  bleached  oro-anic  matter  wiiich  gives  it  translucency  and  greatly 
enhances  the  permanency  of  the  operation.  The  results  obtained  by 
this  method  are  extremely  satisfactory. 

Bleaching  Methods  for  Special  Stains. 

Pulpless  teeth  are  especially  liable  to  discoloration  from  external  and 
accidental  causes.  If  decayed  and  the  cavity  has  remained  unfilled  for 
a  length  of  time  many  substances  ^vhich  find  their  \vay  into  the  oral 
cavity  either  as  food  or  as  medicine  may  produce  discoloration  when 
absorbed  by  the  tooth  through  the  open  cavity  walls. 

3fefalUe  salts  are  particularly  apt  to  cause  such  staining  by  reaction 
with  the  sulfids  with  which  the  dentin  structure  is  usually  saturated 
during  decomposition  of  its  organic  contents.  Many  of  the  medica- 
ments used  in  pulp-canal  treatment  or  even  for  hypersensitive  dentin 
may  stain  the  tooth  structure,  and  finally  the  action  of  sulfids  in  the 
structure  of  a  pulpless  tooth  may  react  with  amalgam  fillings,  forming^ 
salts  of  mercury,  silver,  tin,  copper,  etc.,  which  are  absorbed  by  the 
tooth,  resulting  in  its  discoloration.  The  treatment  of  these  stains,. 
which  were  grouped  as  Class  III.  at  the  beginning  of  this  chapter,, 
is  extremely  difficult  and  often  unsatisfactory.  However,  there  may 
arise  individual  cases  of  discolorations  of  this  class  where  it  is  of  the 
utmost  importance  to  remove  them,  and  much  may  often  be  accom- 
plished when  the  causes  of  the  discoloration  are  known  and  the  proper 
bleaching  method  is  applied. 

Gold  stains  may  arise,  as  has  been  already  indicated,  from  the  inju- 
dicious use  of  gold  instruments  or  failure  to  remove  all  gold  fillings 
when  applying  some  one  of  the  chlorin  methods  of  bleaching.  In  the 
course  of  time  where  this  has  happened  the  tooth  assumes  a  pinkish 
hue  which  merges  into  a  characteristic  violet  or  purple,  finally  becom- 
ing black. 

Iron  stains  may  arise  from  the  use  of  steel  instruments  in  connection 
with  the  chlorin  methods  of  bleaching  or  in  contact  with  iodin  or  any 
of  the  mineral  acids  in  connection  with  canal  treatment.  The  iron 
stain  is  yellowish  at  first,  gradually  becoming  brown  and  finally  black. 

Copper  and  nickel  stains  may  arise  from  contact  ^yith  these  metals 
or  their  alloys,  as  copper  amalgam  or  nickel  or  German  silver 
dowels  for  artificial  crowns  or  anchorages  for  fillings.  The  stains 
from  these  metals  are — for  copper,  bluish  to  black,  and  for  nickel  a 
characteristic  chlorophyll  green  which  eventually  becomes  black. 


BLEACHING  METHODS  FOR  SPECIAL  STAINS.  559 

The  best  general  treatment  for  all  of  the  foregoing  stains  is  to 
re-bleach  the  tooth  by  the  chlorin  method,  with  especial  care  as  to  the 
several  precautions  already  recommended,  and  when  the  color  of  the 
metallic  stain  lias  been  discharged  bv  conversion  of  the  dark-colored 
salt  into  a  soluble  chlorid,  wash  the  tooth  thorouglily  first  with  dilute 
chlorin  water  50  per  cent.,  and  afterward  with  hot  distilled  water  to 
remove  all  of  the  metallic  chlorid  which  has  been  formed.  The  process 
may  require  roj)etition  to  secure  permanent  results. 

Silver  stains  are  comparatively  easy  to  remove,  either  by  an  applica- 
tion of  the  chlorin  method  or  by  saturating  the  tooth  with  tincture  of 
iodin,  thus  converting  the  silver  salt  into  a  chlorid  or  iodid  as  the  case 
may  be,  after  which  it  may  be  dissolved  out  with  a  saturated  solution 
of  sodium  hyposulfite  applied  as  a  bath  to  the  tooth.  For  this  pur- 
pose the  Hollingsworth  bulb  dam  (see  Fig.  483)  answers  admirably, 
and  although  the  experiment  has  not  as  yet  been  tried,  there  is  good 
reason  to  believe  that  the  cataphoric  method  with  electrodes  applied  in 
reverse  order  would  under  these  circumstances  greatly  facilitate  the 
solution  and  removal  of  the  metallic  salts. 

Mercurial  stains  are  always  black  from  the  formation  of  mercuric 
sulfid,and  are  removable  by  the  same  method  as  are  silver  stains,  with 
the  exception  that  where  the  stain  has  been  converted  into  a  chlorid 
by  the  chlorin  method,  the  mercuric  chlorid  is  best  removed  by  an 
aqueous  ammoniacal  solution  of  hydrogen  dioxid,  or  when  the  stain 
has  been  converted  into  mercuric  iodid  by  the  use  of  a  saturated  solu- 
tion of  potassium  iodid.  In  both  cases  a  final  Avashing  with  hot  dis- 
tilled water  is  a  sine  qua  non. 

llanganese  stains  frequently  occur  from  the  use  of  potassium  per- 
manganate, in  solution  or  in  substance,  in  the  treatment  of  putrescent 
canal  conditions.  The  manganese  stain  is  a  characteristic  mahogany 
brown.  It  is  very  readily  removed  by  a  25  per  cent,  aqueous  solution 
of  hydrogen  dioxid  in  which  oxalic  acid  crystals  have  been  dissolved 
to  saturation.  A  few  applications  of  this  mixture  will  quickly  de- 
colorize the  stain,  after  whicli  a  liberal  treatment  of  hot  distilled  water 
is  required  as  in  the  foregoing  cases. 

In  all  cases  a  careful  diagnosis  of  the  chemical  nature  of  the  dis- 
coloration should  be  made  when  possible.  Much  information  upon  this 
point  may  be  gained  by  a  detailed  study  of  the  present  condition  of  the 
tooth  and  its  environment,  but  in  addition  to  this  the  patient  should  be 
questioned  as  to  the  history  of  the  case,  and  especially  as  to  its  previous 
treatment.  The  data  thus  obtained  should  be  carefully  noted  and  treat- 
ment instituted  in  accordance  wdth  the  conditions  to  be  met. 

Success  in  the  bleachino:  of  teeth  demands  a  recotrnition  of  the  fact 
that  each  case   presents    individual   peculiarities,  that  the   problem   is 


560  DISCOLORED   TEETH  AND   THEIR  TREATMENT. 

essentially  a  chemical  one  always,  and  that  the  bleaching  method  in  any 
given  case  mnst  be  selected  with  especial  reference  to  the  character  of 
the  discoloration  and  applied  with  due  care  as  to  its  details  in  order  that 
the  chemical  requirements  of  the  operation  may  be  intelligently  met ; 
without  which  care  success  is  impossible. 


CHAPTER    XXI. 

EXTRACTION  OF  TEETH. 

By  M.  H.  Cryer,  M.  D.,  D.  D.  S. 


Indications  for  the  Operation. 

It  is  impossible  to  formulate  a  set  of  exact  rules  by  which  the  prac- 
titioner may  be  governed,  in  deciding  upon  the  extraction  of  teeth.  So 
many  circumstances  both  local  and  general  must  be  taken  into  consid- 
eration that  little  more  can  be  done  than  to  suggest  the  most  important 
causes  which  demand  the  operation. 

Deciduous  Teeth. — The  indications  for  extracting  deciduous  teeth 
are — 

First :  When  the  teeth  are  a  source  of  irritation  affecting  the  gen- 
eral health  or  comfort  of  the  child  and  do  not  respond  to  treatment. 

Second  :  When  the  deciduous  teeth  are  preventing  the  eruption  of 
the  permanent  teeth  into  their  normal  jjositions.  Occasionally  a  de- 
ciduous tooth  will  assist  in  the  proper  placing  of  a  permanent  one, 
in  which  case  it  should  not  be  removed  as  long  as  it  is  of  such 
use. 

Third  :  When  a  loAver  ])ermanent  incisor  shows  signs  of  erupting  on 
the  labial  side  of  the  deciduous  tooth,  the  latter  should  be  removed  at 
once,  but  if  the  erupting  tooth  appears  on  the  lingual  side  the  removal 
of  the  deciduous  tooth  may  in  that  case  be  delayed  somewhat  longer. 

Fourth  :  When  upper  permanent  incisors  show  a  tendency  to  erupt 
on  the  palatal  side  of  the  temporary  teeth,  the  latter  should  be  extracted, 
but  when  they  are  erupting  on  the  labial  side  the  deciduous  teeth  may 
be  allowed  to  remain  for  a  time,  as  they  are  often  useful  in  forcing  the 
permanent  teeth  outwardly.  This,  however,  must  be  closely  watched 
to  prevent  the  permanent  incisors  from  moving  too  far. 

Permanent  Teeth. — The  indications  for  extraction  of  the  permanent 
teeth  are — 

First :  Diseased  roots  which  cannot  be  cured  and  so  made  useful 
for  crowning,  or  assisting  in  retaining  a  bridge,  ]>late,  or  other  pros- 
thetic device. 

36  561 


562  EXTRACTION  OF  TEETH. 

Second  :  Teeth  of  mastication  tliat  have  lost  their  occhuling  teeth 
and  in  consequence  thereof  are  being  pushed  from  their  alveoli  and  are 
a  source  of  trouble.  As  a  rule,  this  refers  only  to  the  second  or  third 
molars,  and  more  particularly  to  the  third  molar.  When  it  occurs  with 
other  teeth  the  opposite  vacant  space  should  be  filh.'d  by  an  artificial 
tooth  to  })revent  the  extrusion  of  the  natural  tooth. 

Third :  AVhen  incurable  abscesses  originating  from  teeth  in  the 
upper  jaw  tend  to  open  into  the  nasal  chamber,  maxillary  sinus,  or 
zygomatic  fossa,  the  teeth  associated  with  such  abscesses  should  be  ex- 
tracted. AVlien  diseased  teeth  are  the  exciting  cause  of  an  incurable  ab- 
scess in  the  lower  jaw  which  opens  or  threatens  to  open  externally  on 
the  chin,  jaw,  or  below  the  bone  into  or  upon  the  neck,  they  should  be 
removed. 

Fourth  :  Teeth  which  occupy  irregular  positions  in  the  arch,  that 
cannot  be  corrected  so  as  to  become  useful  or  contribute  to  the  gen- 
eral symmetry  of  the  mouth,  should  be  removed. 

Fifth  :  Erupting  teeth  that  are  retarded  because  of  lack  of  room 
in  the  jaw,  if  giving  pain,  should  be  extracted  or  else  the  tooth  that  is 
preventing  the  eruption  should  be  removed.  A  marked  example  of 
this  is  often  found  in  the  eruption  of  the  third  molar  when  all  the  other 
teeth  are  of  good  size  and  are  in  place.  These  molars  when  retarded 
cause  the  greatest  distress,  sometimes  producing  serious  results,  and 
must  be  extracted  ;  if  they  cannot  be  safely  removed  the  second  molar 
may  be  extracted,  in  consequence  of  which  the  third  molar  will  usually 
be  erupted  near  its  place.  When  an  upper  third  molar  is  erupting 
under  the  same  circumstances  there  is  usually  less  difficulty,  as  having 
but  slight  resistance  distally  it  can  erupt  outwardly  or  slightly  back- 
ward, though,  should  it  impinge  upon  the  soft  tissues  covering  the  ramus 
of  the  lower  jaw,  it  should  be  extracted. 

Sixth  :  Teeth  so  badly  diseased  that  they  will  not  respond  to  treat- 
ment and  are  a  source  of  discomfort  to  the  patient  should  be  removed, 
as  they  impair  the  general  health. 

Seventh  :  First  molars.  There  has  been  much  discussion  regarding 
the  early  extraction  of  these  teeth,  many  claiming  that  if  the  pulp  of 
one  becomes  devitalized  at  an  early  period  of  life  and  it  is  deemed  best 
to  extract  it,  the  other  three  should  also  be  removed.  No  fixed  general 
rule,  however,  can  be  given  ;  each  case  must  be  considered  separately. 
There  are  cases  where  the  extraction  of  all  is  necessary,  and  others 
where  it  would  be  a  most  unwise  thing  to  do.  When  the  anterior  teeth 
are  fully  in  position,  the  bicuspids  occluding  correctly  with  their  oc- 
cluding teeth  and  the  second  molars  are  about  to  erupt,  the  case  may 
then  be  one  for  extracting  the  four  first  molars,  provided  it  be  neces- 
sary to  extract  one  of  them,  or  if  it  be  likely  that  one  or  more  of  them 


INDICATIONS  FOR   THE  OPERATION.  563 

will  be  lost  in  a  few  years.  If,  however,  the  bicuspids  are  not  in  good 
position,  it  is  better  not  to  extract  the  first  molars,  as  they  assist  in  keep- 
ing the  jaws  the  proper  distance  apart,  and  preventing  the  lower  anterior 
teeth  from  biting  against  the  upper  gum. 

Removal  of  Sound  Teeth  Preparatory  to  Inserting-  Artificial 
Dentures. — AVhen  preparing  the  mouth  for  an  artificial  denture  the 
removal  of  sound  teeth  may  be  indicated  as  a  measure  of  expedi- 
ency in  relation  to  mechanical  and  hygienic  considerations.  For  ex- 
ample : 

(1)  Roots  which  a  plate  or  bridge  would  cover,  excepting  when  they 
assist  in  holding  the  device. 

(2)  Teeth  from  which  the  gums  have  receded  to  such  an  extent  as 
to  become  useless  or  unsightly. 

(3)  Teeth  that  are  being  extruded  from  their  alveoli  from  the  ab- 
sence of  occluding  teeth.  The  extraction  of  these  depends,  however, 
on  the  extent  of  "  elevation  "  and  the  possibility  of  placing  occluding 
artificial  teeth  in  position. 

(4)  Where  there  is  but  one  tooth  remaining,  or  two  teeth  standing 
together,  or  in  certain  cases  when  several  isolated  teeth  remain  which 
cannot  be  made  to  contribute  to  the  mechanical  adaptation  of  an  arti- 
ficial denture,  extract  when  in  the  upper  jaw.  They  interfere  wdth  the 
fitting  of  an  upper  plate,  but  in  the  lower  jaw  they  may  be  useful  in 
retaining  the  plate. 

(5)  When  there  are  two  teeth,  one  on  each  side  of  the  upper  jaw,  in 
good  position  and  desirable  shape  for  clasping,  do  not  extract  unless 
they  are  the  third  molars  or  the  oral  teeth. 

(6)  In  preparing  the  upper  jaw  when  two  canine  teeth  alone  remain, 
or  when  there  is  also  a  molar  or  bicuspid,  or  both,  and  it  is  decided  to 
extract  the  molars  and  bicuspids,  then  extract  the  two  canine  teeth  also. 
It  has  been  claimed  by  some  of  the  very  best  dental  practitioners,  whose 
opinions  must  be  respected,  that  by  keeping  these  teeth  the  expression 
of  the  face  is  less  likely  to  be  marred.  For  the  following  combined 
reasons,  however,  extraction  is  advised  : 

a.  It  is  very  difficult  to  obtain  a  correct  impression  of  the  mouth 
while  these  teeth  only  are  in  position. 

h.  It  is  nearly  impossible  to  perfectly  match,  grind,  and  arrange  the 
lateral  incisors  beside  single  canines. 

c.  The  adhesion  of  the  plate  to  the  mouth  is  interfered  with,  as  air 
and  food  work  in  between  the  plate  and  these  natural  teeth. 

d.  The  ])late  is  very  nuich  weakened  by  being  cut  out  for  the  accom- 
modation of  these  teeth  at  what  might  be  termed  the  abutments  of  the 
arch. 

In  the  lower  jaw  single  teeth   which  are  sound  are  usually  of  great 


564  EXTRACTION  OF  TEETH. 

iniportanoo.  Thev  slumld  not  bo  removod,  as  they  assist  in  retaining 
a  (Icntuiv  l)V  means  of  clasps  or  other  devices.  Especially  is  this  true 
in  persons  adxanccd  in  years,  as  then  the  alveolar  process  is  generally 
much  absorbed.  It' the  lower  pro(;ess  is  much  absorbed  even  an  imper- 
fect tooth  will  do  good  service  of  this  character  for  a  time,  and  if  it  is 
the  first  plat(!  the  patient  has  worn  it  will  serve  a  good  purpose  by 
assisting  in  the  retention  of  the  plate  until  the  patient  has  become  ac- 
customed to  it,  after  which  the  tooth,  if  giving  trouble  or  if  it  is  un- 
sightly, may  be  removed  and  an  artificial  one  placed  on  the  plate. 

Instruments  and  Accessories  for  Extracting. 

The  instruments  used  in  extracting  teeth  are  forceps  and  elevators 
of  various  shapes  and  sizes. 

Forceps. — The  forceps  should  be  made  of  steel  of  the  best  quality 
for  the  purpose  obtainable,  in  order  to  give  great  strength  and  stiifness, 
and  at  the  same  time  toughness,  so  that  they  will  not  break.  Forceps 
that  will  spring  or  bend  destroy  the  sensitivity  of  the  hand  using  them 
in  such  a  Avay  as  to  prevent  the  operator  from  discerning  in  what  di- 
rection the  resistance  to  extraction  is  being  made.  The  beaks  of  the 
forceps  as  a  general  principle  should  be  shaped  so  as  to  fit  and  adjust 
themselves  to  as  great  a  surface  of  the  various  teeth  or  roots  as  pos- 
sible so  that  they  may  take  a  firm  hold.  They  should  be  at  such  an 
angle  in  relation  to  the  handles  as  will  permit  them  to  be  easily  and 
readily  placed  in  the  proper  position  without  obscuring  the  view  of  the 
tooth  to  be  extracted.  The  inner  surface  of  each  beak  should  be  concave 
in  a  transverse  section  and  without  serrations,  as  these  are  of  no  assist- 
ance, but  tend  to  weaken  the  beaks  and  are  difficult  to  clean.  The  edges 
of  the  concave  portion  should  be  sharp  enough  to  cut  through  the  alveolar 
process  if  necessary.  The  points  of  the  beaks  should  be  sharp  and 
tapering  so  they  can  be  forced  into  position.  The  handles  should  be  of 
a  shape  to  allow  a  firm  grasp,  and  as  the  hands  of  different  operators 
vary  in  shape  and  size  it  will  l)e  evident  that  the  same  size  of  forceps 
handles  will  not  be  perfectly  satisfactory  to  all.  The  curvature  of  the 
handles  should  vary  according  to  the  general  or  special  use  of  the  for- 
ceps. The  curved  ends,  as  seen  in  Fig.  485,  are  of  little  use,  and  should 
be  done  away  with  in  all  forceps  excepting  perhaps  those  made  especially 
for  the  up])er  and  lower  molars. 

The  joints  of  extracting  instruments  should  be  so  made  that  the 
handles  can  be  separated  by  some  simple  mechanism  to  permit  of 
thorough  and  easy  cleansing.  Figs.  485  and  486  represent  an  instru- 
ment of  this   character.     There  are  others  of  the    same    nature,  but 


lySTRLLMhWTS  AND  ACCESSORIES  EOR  EXTRACTING. 


565 


Fig.  485. 


this  being  the  most  simple  and 
the  strongest  should  be  gen- 
erally adopted  unless  a  similar 
device  can  be  adapted  to  the 
*'  knuckle-jointed  "  instrument. 
(Fig.  487.) 

There  should  be  no  sharp 
angles  or  crevices,  and  if  the 
ordinary  forceps  is  used,  that 
portion  around  the  joint  in  a 
transverse  section  should  be  oval. 
Forceps  are  often  made  with 
octagonal  joints,  but  these  should 
be  condemned,  as  they  may 
not  only  hurt  the  lips  of  the 
patient,  but  in  case  of  a  slip, 
which  may  happen  with  the  best 
operators,  they  are  more  liable  to 
cause  injury  by  striking  the  other 
teeth  ;  moreover  they  are  very 
clumsy  and  require  more  room. 

Fig.  486. 


Antiseptic  universal  lower  molar  forceps.  Joint  of  an  antiseptic  lower  molar  forceps 


566 


EXTRACTION   OF   TEETH. 


Unless  the  antiseptic  joint 
(Figs.  485  and  486)  is  used  the 
union  of  the  joints  is  usually 
made  upon  one  of  two  })rineiples  : 
first,  by  one  hall"  passiug  into  a 
mortise  in  the  other  and  held  in 
tlie  centre  by  a  pinion  (Fig.  488). 
The  second  is  known  as  a 
knucklc-joiut  (Fig.  487)  made 
by  each  portion  being  let  half 
way  into  the  other  and  held  to- 
gether by  a  screw.  This  is  a 
neater  joint  and  does  away  with 
many  of  the  objectionable  fea- 
tures noted  in  other  forms  of 
forceps  joint. 

All  handles  should  be  ser- 
rated as  shown  in  the  illustra- 
tions, and  the  iustruments  if 
properly  cared  for  need  not  be 
nickel-plated.  The  number  of 
forceps  in  a  practical  set  will 
vary  with  the  requirements  of 
every  individual  who  extracts 
teeth,  therefore  only  the  general 
principles  which  should  govern 
the  selection  of  a  set  of  instru- 
ments will  be  here  given  ;  at  the 
same  time  the  uselessness  of  a 
verv  larg-e  selection  is  here  em- 
phasized.  As  an  illustration  of 
the  range  of  tooth  extractions 
which  may  be  performed  with  a 
limited  number  of  instruments 
the  force})s  represented  by  Figs. 
488  and  489,  shoAving  the  exact 
size,  Avill  serve  as  examples. 
They  are  smaller  than  the  ones 
generally  used,  especially  in 
America. 

The  instrument  shown  in  Fig. 
488  may  be  used  almost  universally  for  the  up])er  teeth. 

Fig.  489  is  a  forceps  of  the  same  general  character  as  that  in  Fig. 


Knuckle-joint  root  forceps. 


INSTRUMENTS  AND  ACCESSORIES  FOR  EXTRACTING.         567 
488,  only  the  beaks  are  at  a  different  angle  with  the  handles.    This  pair 

Fig.  488.  Fig.  489. 


Universal  njjper  incisor  and  root  forceps. 


Universal  lower  incisor  and  root  forceps. 


may  be  nsed  similai'ly  tor  the  lower  teeth.      These  forceps  are  nsefnl  in 
all  eases,  except  in  the  I'ull   arch,  wlien  either  a  first  or  second  molar  is 


568 


EXTRACTION  OF  TEETH. 
Fig.  490.  Fig.  491. 


!X 


w 


For  the  ten  upper  aiuerior  teeth. 


Root,  upper  front.     Straight. 


INSTRUMENTS  AND  ACCESSORIES  FOR  EXTRACTING. 


569 


to  be  extracted, 
grhuling  surface!^ 


If  the  teeth  are  large,  the  jaw  stroiio;,  and 
concave,  it  is 


the  line  of 


better  to  use  the  special  lower 
molar  forceps  as  shown  in  Figs. 
485  and  498. 

Fig.  490  and  Fig.  491  rep- 
resent very  useful  forceps  for 
extracting  the  ten  upper  an- 
terior teeth.  Fig.  491  has 
longer  beaks  and  its  points  are 
finer.  In  skillful  hands  where 
too  grreat  a  force  will  not  be 
brought  to  bear  on  the  points 
they  are  the  better  forceps. 
Under  nitrous  oxid  and  where 
many  teeth  are  to  be  extracted, 
thus  requiring  rapid  work,  the 
instrument  shoMn  in  Fig.  490 
is  preferable. 

Figs.  492  and  493,  right  and 
left,  represent  forceps  specially 
used  for  extracting  the  first  and 
second  upper  molars  on  either 
side.  The  outer  beak  is  made 
pointed  for  the  purpose  of  pass- 
ing in  between  the  buccal  roots, 
the  inner  beak  is  concave  in 
order  to  gras})  the  palatal  root. 
Figs.  495  and  496  show  bayonet- 
shaped  forceps,  that  illustrated 
by  Fig.  495  being  especially 
made  for  extracting  the  upper 
third  molars,  Fig.  496  being 
used  for  upper  roots.  The  ends 
of  the  handles  of  all  forceps 
which  are  forced  in  by  the  palm 
of  the  hand  should  have  a  broad 
surface  as  shown  in  Fig.  496. 
These  forceps  are  popular  with 
many  operators.  The  writer 
considers  them  clumsy,  as  they 
obscure  the  proper  view  of  the 
tooth  and  its  associated  parts. 


Fig.  492. 


i;i\'lit  wppLT  molar. 


570  EXTRACTION  OF  TEETH. 

Fio.  493.  Fkj.  494. 


Left  upper  molar 


Hawk-beaked  forceps. 


ISSTEVMENTS  AND  ACCESSORIES  FOR  EXTRACTING.         571 
Fig.  495.  Fig.  496. 


Km 


i 
1 


Universal  upper  third  m')lar. 


Dorr's  upper  root  forceps. 


572 


EXTRACTION  OF  TEETH. 


Fjg.  497. 


Fig.  498. 


Universal  lower  canines  and  bicuspids. 


Universal  lower  molars,  designed  by  Dr. 
Chapin  A.  Harris. 


INSTRUMENTS  AND   ACCESSORIES  FOR   EXTRACTING.  573 

Fig.  499. 


Fig.  501. 


Root,  lower.    Half  curved 


Klevator. 


Right  and  left  scalers 
used  for  extracting 
roots. 


574  EXTRACTION  OF  TEETH. 

Forceps  for  E.vtr(ictin(/  Lower  Teeth. — Instead  of  the  beaks  of  the 
forcej)s  beiiii^  iiearlv  on  a  line  with  the  liandles  as  in  those  for  the  u{)[)er 
jaw,  they  are  bent  at  nearly  a  right  angh'.  For  the  incisors  of  tlie  lower 
jaw  there  are  no  better  forceps  than  those  shown  in  Fig.  489.  This 
instrnnient  is  very  useful  in  extracting  the  lower  third  medlar  when  fix- 
ation of  the  jaw  from  diifuse  cellulitis  in  the  region  of  the  temporo- 
maxillary  articulation  renders  it  difficult  to  open  the  mouth  sufficiently 
for  inserting  a  larger  instrument.  In  such  cases  the  forceps  should  be 
carried  backward  in  the  vestibule  of  the  mouth  with  the  inner  beak 
passing  between  the  upper  and  lower  teeth  ;  when  the  beaks  reach  the 
third  molar  the  inner  beak  can  usually  be  forced  over  the  inner  surface 
of  the  tooth  and  into  position,  after  which  the  tooth  can  be  grasped 
and  extracted.  The  forceps  represented  in  Fig.  488  can  also  be  used 
to  advantage  for  these  teeth,  the  operator  standing  behind  and  working 
over  the  head  of  the  patient,  as  shown  in  Fig.  546. 

Fig.  494  exhibits  a  hawk-beaked  forceps  for  extracting  the  anterior 
lower  teeth.  It  is  very  popular  with  some  operators,  especially  those 
in  Europe.     The  writer  does  not  recommend  it. 

Fig.  497  also  exhibits  a  special  instrument.  It  is  made  for  extract- 
ing the  lower  canine  and  bicuspid  teeth  of  either  side.  Fig.  498  is  a 
special  instrument  used  for  the  lower  molars  of  either  side.  The  beaks 
are  pointed,  with  a  convexity  on  each  side  of  the  point  to  allow  it  to 
pass  in  between  the  roots.  The  two  concave  portions  fit  against  each 
root. 

Fig.  499  represents  a  universal  lower  root  forceps. 

Elevators  or  Root  Extractors. — There  are  many  kinds  of 
elevators  used  in  extracting  roots.  Some  are  also  occasionally  used  in 
the  extraction  of  teeth  (usually  the  third  molar). 

Fig.  500  shows  one  of  the  most  useful  forms  of  this  instrument.  It 
is  especially  useful  in  extracting  third  molars  when  the  teeth  in  front 
of  them  are  in  position. 

Fig.  501  represents  two  elevators  ;  they  are  similar  to  right  and 
left  scalers,  being  made  somewhat  heavier ;  they  are  extremely  use- 
ful in  extracting  roots.  They  are  so  unlike  an  extracting  instru- 
ment that  patients  do  not  dread  the  a])pearance  of  them  as  they  do 
that  of  forceps.  By  carefully  inserting  the  blade  with  the  point 
toward  the  root  to  be  removed,  between  it  and  the  adjoining  root  or 
tooth,  and  giving  a  slight  rotary  motion,  the  point  will  force  the  root 
from  its  socket  with  but  little  pain. 

Figs.  537  and  538  illustrate  two  other  forms  of  elevator,  with  their 
mode  of  application  in  the  removal  of  roots. 

Lancets. — Figs.  502  and  503  represent  various  forms  of  lancets, 
the  more  useful  of  which  are  Nos.  1    and   5,  which  are  all  that  are 


INSTRUMENTS  AND  ACCESSORIES  FOR  EXTRACTING.         575 

required  for  lancing;  in  extracting  or  for  relief  of  retarded  eruption  of 

deciduous  or  other  teeth.     Tiiey  are  also  useful  in  general  surgery  of  the 

mouth.     The  handles  should  be  made  of  metal  instead 

Fig.  502.  q^-  ^yood,  in  order  that  they  may  be  thoroughly  sterilized. 

Fig.  503. 


Lancets  with  ebony  handles  and  with  solid  steel  handles. 

Scissors. — A  good  pair  of  curved  scissors,  as  shown 
in  Fig.  504,  should  be  at  hand  in  case  a  portion  of 
gum  tissue  is  found  to  be  attached  to  the  root.  If  the 
scissors  were  slightly  more  curved  they  would  be  even 
better  adapted  for  this  purpose. 

In  connection  with  the  instruments  already  men- 
tioned, there  should  be  a  mouth  mirror  (Fig.  505) 
and  a  few  excavators  and  probes  for  general  exami- 
nation of  the  teeth,  especially  for  examining  the  position 
and  character  of  a  root  or  impacted  tooth  which  it  is 
purposed  to  extract. 

Mouth  Props. — When  an  anesthetic  is  to  be  given 
it  is  advisable  to  use  some  kind  of  a  mouth  prop,  in 
order  to  keep  the  mouth  well  open.  Some  operators  do 
not  use  them,  as  they  may  interfere  with  the  giving  of 
the  anesthetic  by  impeding  respiration  upon  beginning 
the  administration.  The  majority  of  patients,  if  asked 
to  hold  the  mouth  open  while  taking  the  anesthetic, 
especially  nitrous  oxid  and  oxygen,  will  keep  it  open 
during  the  anesthetic  stage. 
Fig.  506  illustrates  excellent  props  devised  by  Dr.  Frederic  Hewitt, 
of  London,  England. 


576 


EXTR ACTION  OF   TEETH. 


V\v,.  504. 


The  Mfx'iianicat.  Mouth-opener  (Fig.  507). — This  inslrumcnt 
is  made  in  various  shapes  and  sizes.  It  is  inserted  between  the  jaws 
wlien  the  ])r()])s  are  to  be  removed  or  in  eases  of  trismus,  and  may  also 
be  used  to  separate  tlie  jaws  and  retain  them  so  in  eases  of  emergency 
or  (bn-ing  eertain  o])erations  within  the  oral  eavity. 

All  denti>^ts,  and  espeeially  those 
who  extract  teeth,  should  have  at 
least  one  ])airof  I'HAiiYNCiEAL  FOR- 
CEPS (Fig.  508).  It  is  possible  that 
they  may  never  be  used,  but  on  the 
other  hand  an  accident  may  occur 
such  as  a  fragment  or  tooth  slip- 
ping into  the  pharynx,  where  if  the 
finger  cannot  reach  it  this  instru- 
ment will  be  absolutely  necessary. 
Surgical  Anatomy. — To  extract 
teeth  successfully  it  is  first  neces- 
sary to  be  perfectly  familiar  with 
the  general  shapes  of  the   difi'erent 

Fig.  50."). 


Curved  scissors. 


Mouth  mirror. 


teeth  and  their  position  in  relation  to  the  jaw  and  to  their  associates,  in 
order  that  the  operator  may  intelligently  apply  the  force  in  the  line  of 
the  least  resistance  required  for  their  removal.  This  knowledge  cannot 
be  obtained  from  books  ;  they  are  but  the  guides  to  it.  The  jaws  of  the 
dead  subject  must  be  dissected — both  the  cleaned  bones  and  those  with 
the  soft  tissues  left  upon  them.  "Dissection"  means  that  not  only 
shall  the  superficial  relations  be  studied,  but  that  the  bones  shall  be  cut 
in  various   directions,  both  with   the  saw  and  other  instruments,  until 


SURGICAL  ANATOMY. 


577 


the  relations  of  the  teeth  of  the  upper  jaw  with  the  floor  of  the  nasal 

chamber  and  the  maxillary  sinus  are  fully  understood.     In  the  lower 

jaw  the  relations  of  the  teeth  with  the  inferior  dental  canal  and  the 

position  of  the  roots,  especially  those  of  the  third  molar,  must  also  be 

thorouijldv  known. 

Fig.  506. 


Hewitt's  mouth  props  (half  size). 


The  alveolar  process  of  both  jaws  is  made  up  of  two  plates,  external 
and  internal,  consisting  of  dense  compact  bone  without  a  true  line  of  de- 


FiG.  507. 


Mechanical  mouth-opener  (half  size). 


markation  between  the  process  and  maxilla  proper.    The  interspaces  be- 
tween these  plates  form  the  sockets  for  the  teeth  and  are  surrounded  by  a 


Fir,.  oOS. 


I'haryngeal  forceps  (half  .size). 


very  thin  cribriform  plate  of  cortical  bone.     The  remaining  space  is  filled 
with  cancellated  tissue,  small  bony  channels,  connective  tissue,  nerves, 

37 


578 


EXTRACTION  OF  TEETH. 


vessels,  etc.  As  this  process  belongs  to  the  teeth,  being  developed  with 
them,  and  is  for  the  jiurposc  of  iiolding  tlieni  in  position,  it  disappears  to 
a  greater  or  less  extent  when  the  teeth  :ire  lost.  The  resorj)ti()n  of  this 
process  does  not  take  place  alike  in  each  Jaw.  In  tlie  ni)j)er  jaw  the 
external  platt'  disapj)ears  more  rapidly  and  to  a  greater  extent  than 
the  inner  plate  ;  in  the  lower  jaw  the  resorption  of  the  two  plates  is 
about  equal  in  extent  and  rate.  The  inner  plate  of  the  upper  jaw  is 
partially  snj)ported  by  the  external  plate  of  the  palatal  process,  in  fact 
one  merges  into  the  other.  The  outer  alveolar  plate  of  the  upper  jaw 
being  resorbed  to  a  greater  extent  than  the  inner  one  is  of  advantage 
to  the  dentist  in  fitting  teeth  to  the  gums  ;  consequently,  in  extrac- 
tion that  fact  should  be  remembered  and  injury  to  the  internal  plate 
avoided.  At  the  same  time  it  does  no  harm  to  remove  a  small  por- 
tion of  the  outer  plate,  though  loss  of  the  gum  tissue  should  be 
avoided  if  pt)ssible.     In  the  lower  jaw  it  is  not  so  im})ortant  to  avoid 


Fig.  509. 


Alveoli  of  permanent  teeth — upper  jaw. 

removing  slight  jiortions  of  the  inner  plate,  as  resorption  takes  place 
about  equally  in  the  two  plates. 

These  plates  may  be  resorbed  in  such  a  manner  that  a  slight  ridge 
is  left  between  the  places  which  they  occupied.  This  resorption  of 
both  plates  of  the  alveolar  process  of  the  lower  jaw  makes  it  more  diffi- 
cult to  fit  single  plain  teeth  in  the  lower  than  in  the  upper  jaw. 


SURGICAL  ANATOMY. 

Fig.  510. 


579 


Alveoli  of  permanent  teeth— lower  jaw. 

Fig.  509  shows  the  alveoli  of  the  upper  denture,  Fig.  510  that  of 

the  lower. 

Fm.  oil. 


Typical  upper  and  lower  jaw. 

Fig.  511  illustrates  a  typical  upper  and  lower  jaw,  the  external  sur- 


580 


EXTRACTION  OF  TEETH. 


faces  of  the  crowns  of  the  teeth,  also  a  normal  occlusion.  Figs.  512 
and  513  illustrate  the  occluding  surfaces  of  the  teeth  and  their  relations 
-with  each  other.     They  are  made  from  the  same  skull  as  Fig.  511. 

Fig.  512. 


Showing  the  occlusal  surfaces  of  the  upper  teeth.    (From  same  .skull  as  Fig.  511.) 

Fig.  514  is  from  a  photograph  taken  from  the  right  side  of  a  skull. 
It  gives   a  good   representation   of  a  fairly   normal   occlusion   of  the 


Fig.  513. 


Showing  occlusal  surfaces  of  the  lower  teeth.    tFrom  same  skull  as  Fig.  511.) 

teeth,  their  shape,  roots,  and  their  relation  with  the  cancellated  tissue 
and  the  inferior  dental  canal  or  cribriform  tube  of  the  lower  maxilla. 


SURGICAL  ANATOMY. 
Fig.  514. 


581 


-liowing  the  buccal  surfaces  of  the  crowns  and  roots  in  position. 
Fig.  5io. 


(From  thu  saiui;  jaw  a>  Fiu 


582 


EXTRACTION  OF  TEETH. 


In  tlic  iij)])('r  jaw  the  bone  is  tliin  over  the  position  of  the  molar  teeth, 
and  their  roots  are  eoinparatively  sti'aijjjht  ;  none  of  these  should  be 
diffieult  to  extraet.  Tlie  hueeal  roots  of  the  first  molar  are  somewhat 
diver<ient  from  eaeli  other.  The  same  roots  of  the  seeond  molar  spread 
only  slightly  as  they  leave  the  erown  and  close  in  at  the  points.     The 


Fig.  516. 


Mtc 


T  ya  Hp 
Hs,  Hiatus  semilunaris;  Mec,  middle  etlimoidal  cells;  CI,  crystalline  lenses;  Up,  uncinate  pro- 
cess ;  3It,  middle  turbinated  bone  ;  Mm,  middle  meatus  ;  Ms,  maxillary  sinus  ;  Ini,  inferior 
meatus;  It,  inferior  turbinated  bone;  Vm,  vestibule  of  mouth;  Isf  M,  first  molar;  Dis.  r.  IM  M, 
distal  root  first  molar;  Idn,  inferior  dental  nerve;  T,  tongue;  Ns,  nasal  septum;  Hp,  hard 
palate. 

roots  of  the  third  molar  are  too-ether  and  slig-htlv  curved  backward.  In 
the  lower  jaw  the  roots  are  comparatively  straight.  Those  of  the  first 
molar  are  s])read  only  a  little  apart,  this  being  the  usual  condition. 
The  roots  of  the  second  molar  are  almost  straight  and  are  nearly  parallel 
with  each  other.  The  anterior  root  of  the  third  molar  curves  slightly 
backward  until  it  joins  the  posterior  root. 

Fig.  515  is  taken  from  the  left  side  of  the  same  jaw  as  Fig.  514.  In 
Fig.  514  the  roots  have  been  exposed  down  to  their  apices ;  in  Fig.  515 
only  the  external  or  cortical  plate  has  been  removed.     These  two  illus- 


SURGICAL  ANA  TOM  Y. 


583 


trations  give  a  correct  idea  of  the  relations  of  the  teeth  to  the  internal 
structures  of  the  jaw. 

Figs.  516  and  517  are  good  ilhistrations  of  the  relations  of  the  roots 


Onii 


1<I  M  l.<l  M 

Oins,  OpcuiuK  maxilliiry  sinus;  1ft  M,  I'lTt^t  molar. 

with  the  floor  of  the  maxillary  sinus  usually  found  in  the  M'hite  race. 
In  the  negro  there  is  usually  a  considerable  thickness  between  the 
teeth  and  the  floor  of  the  sinus.  It  will  be  noticed  that  the  roots  of 
the  molars  pass  up  on  l)()th  sides  of  the  sinus,  and  because  of  this  fact 
it  is  necessary  in  extractiug  teeth  from  a  jaw  of  this  character  to  use 

Fk;.  olS. 


Arlst  ^f,  Anterior  root  of  lirst  molar;  li  M  Bi,  root  of  secoud  bicuspid;  Idn,  inferior  dental 
nerve ;   U,  U-shaped  or  cortical  portion  of  lower  jaw. 

the  greatest  caution,  otherwise  a  ])<)rti(»u  of  the  floor  of  tliat  cavity  might 
also  be  removed.     Or  if  a  tooth  l)e  broken  and  much  ujiward  force  used 


584 


EXTRACTION  OF  TEETH. 


in  endeavoring  to  take  hold  of  the  root,  the  hitter  could  easily  he  forced 
into  the  sinus.  Tiie  lower  portion  of  Fig.  516  gives  a  general  idea 
of  a  transverse  section  of  the  lower  jaw  made  posterior  to  the  mental 
foramen.  Especial  attention  is  drawn  to  the  U-shaped  formation  of 
the  cortical  portion  of  the  lower  jaw  which  terminates  in  the  two  plates 
of  the  alveolar  j)rocess,  and  between  which  the  roots  are  imbedded  in 
the  cancellated  tissue.  It  also  show\s  how  the  roots  extend  toward  the 
inferior  dental  nerve.  There  is  no  line  of  dciiiarkation  between  the 
alveolar  process  and   the  body  of  the  bone. 

Fig.  518  shows  the  relation,  length,  and  })osition  of  the  second  bicus- 


FiG.  519. 


pid,  showing  that  its  root  is  sometimes  placed  to  the  inner  side  of  the 
anterior  root  of  the  first  molar.  The  roots  of  these  bicuspids  are  flat,  as 
will  be  seen  by  looking  at  Fig.  533.    On  taking  into  consideration  their 


SURGWAL  ANATOMY. 


585 


lensftb,  position,  and  tliinness  it  will  be  readily  seen  why  it  is  so  often 
difficult  to  extract  them  without  breaking. 

Fig.  519  is  taken  from  horizontal  sections  of  the  lower  and  upper 
jaws,  showing  the  transverse  sections  of  the  roots  of  the  teeth.  The 
section  is  made  a  little  above  the  margin  of  the  alveolar  process  of  the 
upper  jaw  and  a  little  below  in  the  lower.  The  illustration  shows  the 
shape  and  position  of  the  various  roots,  with  their  relations  to  the  pro- 
cess and  to  each  other.     Particular  attention  should  be  ffiven  to  the  flict 


Fig.  520. 


R  Ut  M 


R  M  Bi. 


R  1st  Bi 


Ihi,  Dental  nerve:  R  3d  .V,  roots  of  third  molar;  R -2d  M,  roots  of  second  molar;  R  1st  .V,  distal 
root  of  first  molar;  R2dBi,  root  of  second  bicuspid;  R  Ut  Bi,  root  of  first  bicuspid;  Re, 
root  of  canine;  Rli,  root  of  right  lateral  incisor. 

that  the  roots  and  i)roce.ss  are  in  such  close  relation  as  to  make  it  im- 
possible to  force  the  beak  of  a  forceps  between  them  without  breaking 
one  or  both  plates  of  the  process.  The  lines  leading  from  the  roots 
show  the  proper  direction  for  applying  what  is  known  in  extracting 
as  the  "  out-and-in  motion." 

Fig.  520  represents  a  horizontal  section  made  through  the  lower  jaw 
near  the  ends  of  the  roots,  and  from  the  same  bone  as  that  shown  in  the 
lower  half  of  Fig.  519.  The  cancellated  portion  with  the  soft  tissue 
filling  the  spaces  can  be  plainly  seen.  The  nerve  passing  into  its  tube, 
the  ends  of  the  roots  of  the  second  and  third  molars,  the  tij)  of  one  of 


586 


EXTRACTION  OF  TEETH. 


the  roots  of  tlio  first  molar,  and  the  roots  of  tlio  first  and  second  liieus- 
pids  are  all  ])lainly  shown.  A  little  of  the  lateral  incisor  can  he  noticed, 
hnt  the  centrals  do  not  reach  so  far  down. 

Figs.  521  and  522  are  taken  from  a  sagittal  section  of  the  upper 
jaw,  external  to  the  infraorbital  foramen,  and  throutih  the  roots  of  the 

Fig.  521.  Fig.  522. 


—  Om 


Ifx,  Infraorbital  sinus;  If,  infraorbital  foramen; 
Pic,  piece  of  paper  passing  through  infraorbital 
canal;  Ms,  maxillary  sinus;  .la,  apical  abscess. 


Om,  Opening  into  malar  boue  ; 
IJ's,  infraorbital  sinus. 


molar  teeth.  This  illustration  shows  how  the  roots  often  extend  above 
the  lower  portions  of  the  floor  of  tlie  sinus,  an  abscess  from  the  palatal 
root  of  the  first  molar  having  discharged  into  the  floor  of  the  sinus 
at  the  point  Aa. 

It  has  been  demonstrated  both  anatomically  and  clinically  that  in- 
fectious matter  from  a  suppurating  tooth  may  eventually  give  rise  to  an 
inflammation  of  the  meninges  of  the  brain.  Should  pus  from  a  dento- 
alveolar  abscess  discharge  into  the  maxillary  sinus  it  may  pass  out  into 
the  hiatus  semilunaris  and  ascend  into  the  frontal  sinus  or  in  the  vicin- 
ity of  the  cribriform  plate  of  the  ethmoid  through  the  infundibulum  when 
the  passage  through  the  hiatus  into  the  middle  meatus  is  small  or  con- 
stricted, as  it  usually  is  when  inflamed,  or  the  pus  may  pass  directly 
through  the  infundil)ulum.  Recent  research  has  shown  that  the  frontal 
sinus,  the  cribriform  plate  of  the  ethmoid,  and  the  meninges  of  the  brain 
are  in  close  relation  at  the  anterior  portion  of  the  cribriform  plate,  a  dis- 
eased condition  at  which  point  is  liable  to  involve  all  three  structures. 

Fig.  523  is  from  a  longitudinal  section  of  the  lower  jaw,  and  gives  a 
good  idea  of  the  cancellated  tissue,  the  relations  of  the  sockets  of  the 
teeth  to  one  another,  and  the  position  of  the  inferior  dental  canal. 


S URGICAL  ANA  TOM  Y. 
Fig.  52o. 


587 


Fig.  5-24. 


i 


%*^ 


"0 


^^ 


.ri 


H 


588 


EXTRACTION  OF  TEETH. 


FiiT.  524  is  taken  fVom  several  transverse  sections  of  a  lower  jaw. 
The  bone  is  not  (juite  nornuil,  as  several  teeth  were  extracted  beibre 
death,  the  loss  having  caused  changes  in  the  character  of  the  bone. 
Some  of  the  sections  show  but  oue  canal  while  in  others  there  are  many, 
requiring  close  observation  to  tell  in  which  the  nerves  and  vessels  have 
passed.  At  point  d  it  will  l>e  seen  that  the  mot  of  the  second  molar 
penetrates  the  true  nerve  canal. 

Fig.  525. 


Fig.  525  is  taken  from  the  inner  side  of  the  right  half  of  a  lower 
jaw.     The  second  molar  has  been  broken  otf,  the  roots  still  remaining 


Fig.  526. 


in  position.    The  points  of  the  roots  of  the  third  molar  pass  out  through 
the  inner  wall  a  considerable  distance  below  the  mvlo-hvoid  ridge.     A 


SURGICAL  ANATOMY. 


589 


portion  of  the  ridge  has  been  cut  away,  exposing  the  remainder  of  the 
internal  surface  of  the  roots.  This  will  be  further  alluded  to  when  ex- 
traction of  the  lower  third  molar  is  considered. 

Figs.  526  and  527  are  from  the  outer  side  of  the  right  half  of  a  lower 

Fig.  527. 


jaw,  Fig.  526  showing  an  impacted  third  molar  lying  horizontally  in 
the  jaw.  Fig.  527  is  of  the  same  jaw  with  the  tooth  removed  from  its 
bed,  showing  the  inner  surface.  The  second  molar  is  a  pulpless  tooth 
the  distal  root  of  which  shows  where  the  impacted  tooth  has  pressed 
against  it,  causing  the  alisorption  of  a  portion  of  the  root  and  exposing 
the  pulp  canal  within,  producing  death  of  that  organ.  This  must  have 
caused  neuralgia.  The  cancellated  tissue  of  this  bone,  it  will  be  noticed, 
is  not  like  that  shown  in  Fig.  512,  the  change  in  the  character  of  this 
tissue  being  the  result  of  irritation  caused  by  the  impacted  tooth.  It 
will  be  seen  that  the  roots  of  the  other  teeth  in  this  jaw  are  longer 
than  usual,  the  canine  tooth  passing  below  the  nerve  and  to  the  outer 
side. 

Figs.  528  and  529  represent  the  inner  ■^ide  of  the  left  half  of  a  lower 
jaw.  It  shows  an  impacted  third  molar  pointing  slightly  downward. 
The  distal  root  of  the  second  molar  is  slightly  absorbed.  On  uncover- 
ing the  tooth  and  taking  it  from  its  bed,  it  was  found  to  be  incased  in  a 
thin  shell  of  bone  as  though  the  dental  sac  had  ossified  separately  around 
this  tooth  ;  this  thin  incasement  of  bone  may,  however,  have  been  an 
inflammatory  product.  The  inner  portion  of  this  shell  can  be  seen  in 
position.  The  nerve  and  its  accompanying  tissue  passes  into  the  infe- 
rior dental  foramen  immediately  against  the  shell  and  has  the  appear- 


590 


EXTRACTION  OF  TEETH. 


ance  of  being-  flattonod  out.     It  divides  and  sends  a  branch  around  the 
internal  half  of  the  shell. 

Fig.  528. 


Inner  side  of  left  half  of  lower  jaw,  showing  an  impacted  third  molar. 

Figs.  530  and  531   are  taken  from  the  right  and  left  halves  of  the 
lower  jaw.     Fig.   530  shows   the   internal   surface  of   the   right  half; 

Fig.  529. 


(Same  as  Fig.  528.) 


Fig.  531,  the  external  surface  of  the  .^anie.      In  Fig.  530  the  roots 
of  the  third  molar  curve   backward,  are   joined  together,  and  are  so 


SURGICAL  AS  ATOMY. 


591 


enlarged  bv  an  abnormal  deposit  of  cementum  caused  by  continued 
hyperemia  due  to  the  prolonged  irritation  that  the  form  of  each  root 
is  lost ;  the  bone  also  is  much  thickened.     Fig.  531  shows  an  impacted 


Fig.  530. 


Right  lialf  of  lower  jaw. 


tooth  pressing  directly  against  the  one  in  front  of  it,  the  roots  of  which 
have  become  much  enlarged  by  the  deposit  of  cementum.  The  sur- 
rounding bone  is  also  thickened  and  much  more  compact  than  the  nor- 
mal bone.  The  character  of  the  cancellated  tissue  of  the  lower  jaw  is 
lost  by  the  deposit  of  bone  caused  by  continued  irritation  of  that  tissue. 

Fig.  531. 


^=-^-^'^i 


l.cft  half  of  lower  jaw. 

Figs.  532  and  533  show  the  normal  forms  of  the  teeth,  and  Fig.  534 
is  taken  from  a  group  of  abnormal  teeth.  If  only  normal  conditions 
of  the  teeth  had  to  be  considered,  as  shown   in  Figs.  532  and  533,  ex- 


592 


EXTRACTION  OF  TEETH. 


traction  would  be  a  very  simple  operation,  but  unfortunately  this  is 
seldom  the  case.  It  often  happens  that  even  when  the  teeth  them- 
selves are  normal  they  are  situated  in  abnormal  positions,  and  for  this 


Fir;.  532. 


Deciduous  teeth — left  side  (Burchard). 


reason  alone  their  extraction  becomes  necessary.  In  fact,  so  varied  and 
complicated  are  the  different  abnormalities  ])resented  that  it  would  be 
impossible  to  describe  them  all.    The  diagnosis  of  unerupted  teeth  occu- 


FiG.  533. 


Permanent  teeth— right  side  (Burchard). 

pying  abnormal  positions  has  been  greatly  facilitated  by  special  applica- 
tions of  the  skiagraphic  method.  Its  general  use  in  this  connection  is 
but  a  question  of  time  and  further  development.  A  careful  study  of 
the  complications  most  frequently  occurring  will,  however,  give  good 
preparation  for  meeting  the  emergencies. 

Figs.  525  to  531  and  535  show  abnormal  positions  of  various  teeth. 
It  will  be  readily  seen  that  no  set  of  rules  could  be  made  to  govern  the 


593 


Aljiiormalities  in  tetth. 

extraction  of  these  teeth  ;  therefore  only  the  general  principles  govern- 
ing extraction  can  be  here  set  forth. 

General  Principles  in  Extracting  Teeth. 

These  principles  may  be  classified  under  the  following  heads : 

(1)  Management  and  Position  of  Patients. 

(2)  Selection  of  Instruments. 

(3)  Techni(jue  of  the  Operation. 

38 


594  EXTRA  CTIOX   OF  TKETII. 

Manag-ement  of  Patients, — The  first  important  step  toward  a  suc- 
cessful operation  in  dentistrv  is  to  ^ain  the  confidence  of  the  patient, 
who  must  be  hrouoht  to  rely  entirely  on  the  iud<i:ment  and  skill  of  the 


^^,^4^ 


AbiKirmal  jaw  showing  impacled  canines. 

operator.  If  the  operator  feels  entire  confidence  in  his  own  ability  to 
successfully  carry  out  an  operation  he  can,  by  his  manner  of  approaching 
the  patient,  impart  a  feeling  of  almost  absolute  trust  in  his  skill.  This 
feeling  of  confidence  in  himself  should  be  cultivated,  as  it  is  evident 
that  a  slight  nervousness  on  his  part,  even  though  he  be  most  skillful, 
will  tend  to  alarm  the  patient  to  such  an  extent  as  may  cause  great 
interference  with  the  operation. 

Position  of  the  Patient. — The  principal  object  to  secure  in 
placing  the  patient  is  to  obtain  a  good  view  of  the  affected  tooth  and 
contiguous  parts  ;  after  which  the  position  should  be  made  as  comfort- 
able as  possible  both  for  the  patient  and  operator,  taking  care  that  the 
territory  of  operation  can  be  reached  with  but  little  strain  or  efibrt. 

The  position  both  of  ])atient  and  operator  varies  slightly  for  the 
extraction  of  each  tooth.  The  main  points  to  be  observed  are  to  have 
the  particular  tooth  to  be  ojjerated  u])on  in  view,  and  the  head  of  the  pa- 
tient in  such  a  position  that  it  can  be  controlled  by  the  left  arm  and  hand. 

The  chair  should  be  steady,  strong,  and  comfortable,  with  arms  and 
a  good  head-rest  of  rather  a  concave  shape.  It  should  also  have  a  suit- 
able foot-rest.  When  the  regular  dental  chair  is  not  obtainable,  an 
ordinary  strong  wooden  chair  can  be  used.  If  two  of  these  chairs  are 
placed  back  to  back  the  extra  one  gives  a  good  place  for  the  left  foot 
of  the  operator,  and  a  head-rest  may  thus  be  made  of  his  thigh.  The 
patient  should   be  directed  to  grasp  the   seat  at  both   sides  with  his 


GENERAL  PRINCIPLES. 


595 


hands.  At  times  it  may  be  necessary  to  extract  while  the  patient  is  in 
bed  or  on  an  operating  table ;  in  such  cases  the  operator  must  obtain 
the  best  position  available.  Where  an  operating  table  or  couch  is  used 
it  is  well,  if  possible,  to  stand  at  the  head  of  the  couch  or  table  and  a 
little  to  one  side  of  the  patient.  By  reaching  over  the  head,  the  for- 
ceps shown  in  Fig.  488  may  be  used  to  advantage  in  work  on  the  lower 
jaw;  the  same  forceps  may  be  used  for  the  upper  jaw  by  standing  to 
one  side  of  the  patient.  If  the  operator  is  ambidextrous,  so  much  the 
better,  as  it  is  very  advantageous  to  be  able  to  use  the  instrument  in  the 
left  hand,  especially  in  extracting  the  teeth  of  the  right  side  of  the  lower 
jaw.  If,  however,  only  the  right  hand  can  be  used,  the  operator  should, 
as  a  rule,  stand  at  the  right  of  the  chair,  the  left  arm  and  hand  being 
used  in  various  ways  to  control  the  head  of  the  patient.  The  mouth  is 
opened  as  far  as  necessary,  and  the  left  hand  is  then  used  to  hold  the 
li})s  away  and  keep  the  jaw  as  steady  as  possible.  (Sec  Figs.  543,  544.) 
Selection  and  Use  of  Instruments. — The  selection  of  instruments 
depends  on  the  nature  of  the  operation  to  be  performed.  The  means 
used  in  extraction  should  be  of  the  most  simple  character.  Many  de- 
ciduous teeth  and  permanent  teeth  from  about  which  most  of  the  pro- 
cess has  been  resorbed  can  often  be  easily  extracted  witli  the  thumb 
and  finger.  Children  feel  less  apprehension  with  this  method  than 
Avhen  an  instrument  is  used.  The  thumb  should  be  covered  with  a 
napkin  and  placed  on  the  inner  surface  of  the  tooth  with  the  fingers 
against  the  outside  of  the  jaw.  The  tooth  is  then  forced  outwardly 
toward  the  cheek  or  lips.  The  roots  of  the  deciduous  teeth  often  break, 
but  this  is  of  little  importance,  for  when  extraction  is  demanded  the  roots 
are  weakened  by  the  natural  process  of  resorption  and  will  soon  disappear. 
Elevators  of  the  various  patterns  shown  in  Figs.  500,501,  536,  537,  and 


Fig.  536. 


Manner  of  holding  elevator  Fig.  500. 

538  should  be  used  whenever  practicable  for  removing  roots,  and  in  some 
cases  teeth  also.     Fig.  500   is  especially  u.sefid  in    removing  the  third 


596 


EXTRACTION  OF  TEETH. 


molars.     When  tlic  internal  anatomy  of  the  jaws  is  well  understood, 
this  will  be  appreciated. 

Fig.  537. 


Elevator  in  use  labially. 


Fig.  519  shows  how  firmly  the  roots  are  embraced  at  their  necks 
between  the  two  hard  plates  of  compact  tissue.     It  is  usually  impossible 


Fig.  538. 


Elevator  in  use  lingually. 


to  force  an  instrument  between  the  roots  of  teeth  and  these  plates  with- 
out breaking  the  internal  or  external  walls  of  the  latter.  The  cancel- 
lated tissue  between  these  plates  is,  however,  soft  and  yielding,  and  into 


GENERAL  PRINCIPLES.  597 

this  a  properly  shaped  elevator  can  be  passed  between  the  roots.  After 
pushing  the  instrument  with  the  point  toward  the  root  to  be  extracted 
and  the  back  toward  the  contiguous  tooth  or  root,  using  the  latter  as  a 
fulcrum,  revolve  the  elevator  slightly,  prying  at  the  same  time,  and  the 
root  will  leave  its  socket  with  little  or  no  injury  to  the  surrounding  tis- 
sue. Elevators  should  be  firmly  grasped  and  held  in  such  a  manner 
that  if  a  breakage  or  slip  should  occur  the  instrument  will  be  prevented 
from  wounding  the  soft  tissue.  If  root  forceps  were  used  in  cases  of 
this  kind  it  would  be  almost  impossible  to  avoid  injuring  one  or  the 
other  of  the  plates  when  removing  the  root.  It  is  often  advisable  to 
use  the  forceps  by  passing  the  beaks  between  the  plates  and  grasping 
the  root  on  its  approximal  surfaces,  instead  of  the  external  and  internal 
surfaces.  Even  whole  teeth  may  be  extracted  in  this  way  when  there 
are  no  adjoining  teeth  or  roots.  A  similar  plan  is  sometimes  used  in 
rapid  extracting  under  nitrous  oxid,  where  roots  or  teeth  have  been 
extracted  on  each  side  of  a  tooth,  the  beaks  passing  into  the  sockets 
of  the  extracted  teeth,  thus  grasping  the  tooth  to  be  removed  on  its 
approximal  sides.  This  mode  of  operating  must  be  followed  with 
care,  especially  in  teeth  situated  below  the  maxillary  sinus,  as  the  floor 
of  that  cavity  may  be  easily  injured.     (See  Figs.  516  and  517.) 

Lancing. — Lancing  for  extraction  is  not  usually  required,  though 
there  are  cases  where  it  is  quite  necessary.  If  the  teeth  have  been 
standing  alone  for  a  long  time,  especially  those  in  the  back  part  of  the 
mouth,  the  gums  are  apt  to  become  firmly  attached  to  them  ;  when  this 
is  the  case  it  is  well  to  sever  the  connecting  tissue  by  the  use  of  the 
lancet  before  extracting.  In  extracting  roots  where  it  is  necessary  to 
remove  a  portion  of  the  external  plate  of  the  alveolar  process,  it  is  well 
to  make  an  incision  in  a  line  over  the  root,  through  the  gum  to  the 
bone  ;  it  is  even  advisable  to  slightly  dissect  the  gum  and  periosteum 
from  the  bone  on  each  side  of  the  cut.  This  is  done  in  order  that  the 
external  beak  of  the  forceps  may  be  passed  along  the  bone  as  far  as  de- 
sired. By  thus  lancing,  the  parts  will  afterward  come  together  and 
quickly  heal,  whereas  if  the  gum  is  cut  by  the  forceps  it  will  not  heal 
so  well.  In  extracting  roots  in  the  lower  jaw,  if  the  lancing  would 
cause  the  blood  to  cover  the  parts  and  obscure  the  operator's  view  it 
should  be  omitted. 

Use  of  Forceps. — As  nearly  all  operators  are  right-handed,  the 
instruction  as  to  the  use  of  forceps  will  be  given  with  that  understand- 
ing, most  of  the  special  instruments  being  made  for  that  hand.  The 
forceps  are  grasped  in  the  right  hand  with  the  palm  toward  the  body, 
the  thumb  on  top  of  and  partially  between  the  handles  (which  will  indi- 
cate to  a  great  extent  the  amount  of  pressure  being  exerted  upon  the 
tooth),  pressing  against  the  handle  nearest  the  palm  just  back  of  the 


598 


EXTRACTION  OF  TEETH. 


joint.     The  first  fino;cr  should  rest  a  little  between  the  handles,  thns 
giving  a  firmer  grij)  on  the  right  handle  (see  Fig.  5.39),  which  might  he 


Fiu.  539. 


Use  of  forceps. 


termed  the  fixed,  or  passive,  handle  ;  while  the  other  one  is  the  movable, 
or  active,  handle.     Many  operators  do  not  place  the  first  finger  between 


Fig.  540. 


Use  of  forceps. 


the  handles  (see  Fig.  540).     The  second  and  third  fingers  pass  to  the 
outside  of  the  left  handle  and  are  used  to  close  the  forceps,  while  the 


GENERAL  PRINCIPLES,  599 

little  finger  resting  between  the  handles  is  used  to  open  the  forceps, 
the  thumb  being  used  to  force  the  beaks  into  the  required  position. 
After  the  forceps  are  in  position  for  extracting,  the  first  finger  is 
placed  along  the  side  of  the  second  finger  to  give  more  power  to 
extract. 

After  it  has  been  decided  to  extract  by  using  the  forceps,  the  par- 
ticular forms  indicated  must  be  selected  and  arranged  in  a  convenient 
place,  ready  for  immediate  use  as  needed.  Especially  should  this  be 
the  case  when  the  operation  is  done  under  the  anesthetic  influence  of 
nitrous  oxid.  It  is  under  such  conditions  that  the  fewer  forceps  used 
the  better  ;  the  writer  generally  uses  but  one  forceps  (Fig.  489)  for  the 
extraction  of  any  or  all  teeth  except  the  first  and  second  molars  ;  for 
those  teeth,  when  the  other  teeth  are  in  position,  he  advises  using  the 
special  forceps. 

Having  the  patient's  head  in  position,  the  forceps  are  grasped  as 
previously  described  and  the  beaks  adjusted  to  the  tooth.  As  a  rule, 
the  inner  beak  should  be  placed  in  position  first,  and  then  the  outer 
one — this  is  very  important,  especially  for  the  lower  teeth — taking  care 
not  to  include  a  portion  of  the  tongue  or  the  soft  tissues  of  the  floor 
of  the  mouth,  as  both  are  liable  to  get  in  the  way.  When  the  forceps 
are  adjusted  to  the  inner  and  outer  surfaces  of  the  tooth,  they  should 
be  forced  between  it  and  the  gum  until  they  come  in  contact  with  the 
edge  of  the  alveolar  process.  It  is  a  common  error  of  students  to  use 
too  much  force  in  pressing  the  handles  together;  only  sufficient  force 
should  be  used  to  securely  hold  the  tooth  or  root.  The  forceps  should 
grasp  as  much  of  the  roots  as  possible,  avoiding  pressure  upon  the 
crown  and  being  careful  not  to  force  the  beaks  between  the  alveolar 
plates,  as  this  would  result  in  breaking  one  or  both  plates  over  the 
tooth  or  root  extracted  and  also  over  the  adjoining  tooth.  Cases  have 
occurred  in  which  the  entire  external  ]>late  of  one  side  has  been  forced 
off  in  this  way. 

At  times  it  may  be  advisable  to  take  away  a  portion  of  the  outer 
plate,  in  which  case  the  lancet  shown  in  Fig.  502  should  be  used  to  cut 
through  the  gum  a  little  beyond  the  point  of  process  to  be  removed, 
dissecting  up  the  gum  slightly  ;  the  inner  beak  is  then  adjusted  and  the 
outer  one  passed  between  the  divided  gum  and  the  process  as  far  as 
required  ;  the  forceps  should  then  be  closed  with  only  sufficient  force 
to  cut  through  the  bone  and  grasp  the  tooth,  taking  care  not  to 
crush  it. 

After  the  forceps  are  in  position  the  tooth  is  loosened  by  rotating  it 
slightly  if  it  be  a  round  conical-rooted  tooth,  such  as  a  central  incisor, 
but  if  it  be  a  flattened  one  it  should  be  removed  by  an  outward  and 
inward  movement. 


600  EXTRACTION  OF  TEETH. 

By  the  "out-aml-iii  motion"  is  mcjint  that  after  the  forceps  are  ap- 
plied the  force  used  in  loosening  teeth  is  directed  in  such  :i  manner 
that  the  tooth  is  worked  outward  and  inward  from  tlic  median  line 
of  the  mouth  (see  Fig.  519,  in  which  the  lines  show  the  direction  of 
the  motion  for  each  tooth).  The  individual  teeth  do  not  always  bear 
the  same  relation  to  the  median  line  of  the  jaw  as  shown  in  Fig.  519. 
When  the  axis  of  a  tooth  is  not  regular  it  should  be  loosened  by  mov- 
ing backward  and  forward,  and  the  movement  should  be  in  line 
with  its  strongest  diameter,  which  lessens  the  danger  of  breaking  the 
tooth. 

In  the  upper  jaw  the  inward  movement  is  made  after  the  outer,  but 
with  not  so  much  force,  as  the  structure  on  the  inner  side  is  more 
dense. 

Rotation  of  a  tooth  in  extracting  is  seldom  practiced,  as  the  single- 
rooted  teeth  are  usually  flattened  and  teeth  that  have  more  than  one 
root  cannot  be  rotated.  Of  the  single-rooted  teeth,  the  upper  central 
incisors  alone  have  roots  nearly  conical  in  shape  which  permit  rota- 
tion as  well  as  the  out-and-in  motion.  A  rotary  motion  is  usually  of 
advantage  in  extracting  the  roots  of  the  upper  first  bicuspid  when 
double,  and  of  the  u})})er  molars  after  the  crowns  are  broken  away  so 
that  the  roots  are  disunited.  These  roots  are  usually  round,  conical, 
and  somewhat  curved  in  shape. 

If  possible,  the  tooth  should  be  kept  in  view  during  the  operation 
so  that  the  results  of  the  movements  may  be  seen.  A  beginner  may 
let  the  forceps  slip  and  extract  the  w^rong  tooth  when  he  is  not  observ- 
ing each  movement,  but  an  experienced  operator  can  dej)end  on  his  sense 
of  touch  to  a  very  great  extent.  The  amount  of  pressure  a  tooth  will 
stand  wliile  loosening  it  by  an  "  out-and-in  motion  "  depends  on  the  size, 
condition,  and  density  of  the  bony  tissue  surrounding  it.  Experience  is 
the  only  reliable  guide  in  this  matter.  When  a  tooth  resists  ordinary 
effort,  if  the  operator  is  not  quite  sure  of  the  cause  of  the  resistance 
of  the  tooth,  it  is  better  to  desist  temporarily  and  allow  the  patient  to 
rest  in  order  to  investigate  the  condition  of  the  tooth  and  its  surround- 
ings. Fig.  530  will  give  some  idea  of  the  causes  of  the  resistance 
offered  by  apparently  normal  crowns. 

After  the  forceps  are  applied  and  the  tooth  slightly  moved,  if  the 
operator  has  a  cultivated  sense  of  touch  he  will  feel  that  the  tooth  is 
yielding  in  one  particular  direction ;  as  a  general  rule  the  tooth  should 
be  carried  in  that  way. 

The  force  applied  to  safely  and  judiciously  extract  teeth  should  be 
made  with  arm  and  wrist  motion  ;  if  the  whole  body  is  used  the  sense 
of  touch  is  blunted  and  accidents  are  liable  to  occur. 

Extracting  Deciduous  Teeth. — In  extracting  the  deciduous  teeth 


GENERAL  PRINCIPLES— DECIDUOUS  TEETH. 


601 


the  principles  involved  are  nearly  the  same  as  for  the  permanent.  A 
care,  however,  must  be  taken  that  is  not  necessary  Avith  the  perma- 
nent teeth,  i.  e.  to  avoid  injuring  the  developing  permanent  teeth  that 
are  situated  immediately  beneath  them. 

Fig.  541,  Avhich  shows  all  the  deciduous  and  the  developing  perma- 
nent teeth  except  the  third  molars,  gives  a  true  idea  of  their  relative 
positions.  Special  attention  is  drawn  to  the  position  of  the  crowns  of 
the  bicuspids  as  related  to  the  deciduous  molars.  It  will  be  seen  that 
they  are  situated  between  the  roots  of  the  latter  teeth,  and  by  using 
undue  force  in  adjusting  the  forceps  these  crowns  could  easily  be  mis- 
placed, extracted,  or  injured. 

If  the  deciduous  teeth  are  extracted  at  the  proper  time  they  can 
usually  be  removed  by  tlu'  thumb  and  finger  as  described.  If  not, 
one  of  the  forceps  shown  in  Figs.  488  and  489  should  be  used. 


Fig.  541. 


Dentures  of  a  child  six  years  uf  age. 


Extraction  of  Individual  Permanent  Teeth. 

The    anatomy   of  the   individual   teeth   and   the   majority   of  their 
often-repeated   variations  as   well    as    the   general    principles   govern- 


602  EXTR ACTION  OF  ThETH. 

intr  the  extractin<>:  operation  heinti;  understood,  the  extraction  of  each 
tooth  will  now  be  studied,  those  of  the  n})])er  jaw  beino;  first 
considered. 


The  Upper  Teeth. 

THE    CENTRAL    INCISOR. 

This  tooth  has  a  stron<>:,  round  conical  root.  The  force[)s  are  carried 
into  position  bv  ])laein<j  the  inner  beak  at  the  ])alatal  surface  of  the  neck 
of  the  tooth  ;  tlic  outcM'  one  is  then  ])laced  in  ])()siti(»n  and  the  instru- 
ment forced  ujnvard  with  a  slight  rotary  motion  between  the  ginn  and 
the  tooth  until  it  comes  in  contact  with  the  alveolar  process.  As  the 
root  is  round  and  conical,  it  is  loosened  by  rotation  and  the  out-and- 
in  motion  and  then  removed  by  drawing  it  directly  from  its  socket. 
It  is,  as  a  rule,  easily  extracted. 


THE    LATERAL    INCISOR. 

This  tooth  is  much  smaller  than  the  central.  The  root  is  flattened 
and  somewhat  curved,  the  apex  being  often  bent  in  the  direction 
of  the  canine  teeth.  After  applying  the  forceps  as  directed  for 
the  central  incisor,  the  motion  should  })e  outward  and  inward.  As 
the  tooth  has  a  delicate  root,  the  force  used  must  be  light.  When 
loosening  and  removing  it,  care  must  be  exercised,  as  its  root  is  not 
straight.  The  tooth  is  carried  in  the  direction  of  the  least  resistance, 
which  is  usually  toward  the  canine  tooth. 


THE    CANINE. 

This  tooth  is  usually  more  firmly  set  in  the  jaw  than  any  other,  and 
it  often  requires  considerable  force  to  break  up  its  attachments.  The 
root  is  long  and  slightly  flattened.  After  applying  the  forceps  its 
attachments  are  broken  up  by  the  out-and-in  motion.  After  loosening 
it  is  usually  easily  removed  from  its  socket.  As  this  tooth  is  erupted 
after  the  adjoining  teeth  are  in  position,  it  is  often  malposed.  If  the 
deciduous  canine  has  been  lost  before  its  proper  time,  and  the  first 
bicuspid  has  pushed  forward,  there  is  no  room  for  the  canine  to  take 
its  true  position.  This  irregularity  varies  to  a  great  extent.  The 
canine  may  also  be  out  of  position  from  unknown  causes.  A  marked 
specimen  is  seen  in  Fig.  535,  where  both  canines  are  im])acted.  They 
were  entirely  covered  by  a  bony  lamina. 

Sometimes  the  roots  of  these  teeth  project  into  the  mjlxillary  sinus, 


iMG.  542. 


THE   UPPER   TEETH.  603 

or  even  into   the   nasal  ehamber,  while  the  crowns  are  impacted  be- 
tween  the  palatal   plate  and   the    plate   forming 
the  floor  of  the    nose.       Fig.   542    represents  a  Fig.  542. 

canine,  lateral,  and  central  incisor  Avhich  were 
extracted     from     the     sinus,     the     roots    being 

imbedded    in    its    inner    Avail.     Teeth    thus    im-  ''      W    \        ^-'^ 

pacted  are  often  a  source  of  trouble  in  \avi- 
ous  ways  and  when  discovered  should  bo  re- 
moved.      When    the    tooth    is    S(^  covered    bv  bone      Canint,  latnal,  and  central 

that  the  fl>rceps  cannot  be  applied  th^  bone  Z^^S^J^^T  ^^"^ 
must  be  cut  away  sufficiently  to  allow  the  forceps 

to  grasp  it.  A  very  good  instrument  for  removing  the  bone  in  the 
upper  jaw  is  the  elevator  shown  in  Fig.  500 ;  after  the  point  has  been 
sharpened   it  may  be  used  as  a  chisel  or  gouge. 

THE    BICUSPIDS. 

The  first  bicuspid  usually  has  a  bifurcated  root  and  the  only  motion 
that  can  be  used  safely  for  loosening  is  the  out-and-in,  as  these  roots  are 
sometimes  considerably  divergent.  The  removal  after  loosening  is  not 
always  easily  accomplished,  a  little  outward  pressure  being  frequently 
necessary.  If  the  force  required  is  used  too  suddenly  the  inner  root  is 
liable  to  break. 

The  second  hicuMpid  usually  has  a  single  flattened  root,  though  occa- 
sionally it  is  bifurcated.  The  motion  used  to  loosen  this  tooth  is  the 
outward  and  inward,  using  the  same  precaution  as  with  the  first  bicus- 
pid on  account  of  the  possibility  of  a  double  root. 

THE    FIRST    AND    SECOND    MOLARS. 

These  teeth  are  nearly  similar,  having  three  roots,  two  buccal  and 
one  palatal,  which  vary  so  much  in  degrees  of  separation  that  no  set 
rule  can  be  given  for  their  extraction.  The  roots  of  the  first  are  usually 
more  divergent  than  those  of  the  second.  Only  the  out-and-in  motion 
can  be  used,  rotation  being  out  of  the  question  in  loosening  them,  as 
the  roots  often  diverge  to  a  great  extent.  (See  p,  Fig.  534.)  After  the 
tooth  has  been  loosened  there  is  at  times  a  difficulty  in  removing  it, 
on  account  of  the  distance  around  the  three  roots ;  owing  to  their 
divergence  this  distance  is  greater  than  the  size  of  the  anatomical 
neck  of  the  tooth  corresponding  to  the  opening  of  the  socket.  The 
only  general  rule  that  can  be  given  is  to  carry  it  in  the  direction  of 
the  least  resistance.  Each  tooth  has  more  or  less  of  an  individual 
character,  and  therefore  the  operator  must  be  governed  by  circum- 
stances. The  main  precaution  to  be  observed  is  not  to  be  in  too 
great  haste,  as   there  is  danger  of  breaking  one  of  the  roots  or    re- 


604 


EXTRACTION  OF  TEETH. 


moving;  a  large  })iccc  of  the  outer  plate  of  the  alveolar  process.     (See 
Accidents,  p.  612.) 

THE    THIRD    MOLAR. 

This  tooth  so  varies  as  to  the  sliape  and  inimber  of  its  roots  that  it 
is  seldom  spoken  of  as  an  abnormal  tooth,  no  matter  in  wiiat  form  or 

Fig.  543. 


Showing  position  for  extracting  upper  teeth  of  left  side. 


position  it  may  be  found  ;  the  greater  number  have  roots  curved  back- 
ward and  outward.  Their  position  in  the  jaw  also  varies  considerably. 
The  forceps  shown  in  Fig.  488  is  the  instrument  to  use  in  extracting. 
After  the  forceps  have  been  firmly  placed,  the  principal  motion  is  the 
out-and-in,  though  more  out  than  in.  If  there  is  much  resistance  the 
hand  should  be  carried  outward  and  upward,  or  in  the  direction  of  the 
least  resistance.     This  tooth  is  sometimes  erupted  at  the   side  of  the 


THE   UPPER   TEETH.  605 

alveolar  process  (Fig.  545)  with   its  occlusal  surface  pointing  toward 

Fig.  544. 


Showing  position  for  extracting  upper  teeth  of  right  side. 

the  check.     It  is  not  well   to  have  the  mouth  opened  too  far,  as  it 
brings  the  coronoid  process  of  the  lower  jaw  in  the  way. 

Fig.  545. 


An  inipiicted  tliird  molar. 

In  stating  the  general  rules  of  extracting,  caution  was  given  not  to 


(JOO  EXTRACTION  OF  TEETH. 

inakt'  the  inovciuciits  faster  than  could  l)c  seen  ;  this  applies  vei-y  pai'tie- 
iilarlv  to  the  thirti  molar.  It  is  so  near  the  ascendini;-  ramus  in  the 
lower  jaw  that  it  is  possible,  especially  when  the  roots  are  curved  and 
spread  out,  to  fracture  this  angle,  or  in  the  U])per  jaw  the  tuherosity  may 
he  hrokcn  away,  thus  opening  into  the  maxillary  sinus.  The  gum  tis- 
sue often  adheres  to  the  posterior  portion  of  this  tooth  ;  when  this  lui])- 
\i{^n<.  it  is  best  to  desist  from  attempts  at  (extraction  and  sever  the  tissue 
from  it  with  a  curved  lancet  or  scissors  before  removing  the  tooth  with 
the  forceps,  or,  as  before  advised,  dissect  the  gum  away  before  applying 
the  forceps. 

The  Lower  Teeth. 

As  a  rule,  the  teeth  of  the  lower  jaw  are  more  difficult  to  extract 
than  are  those  of  the  upper  jaw,  the  lips  and  cheeks  being  in  the  way. 
The  tongue  is  also  troublesome,  covering  the  tooth,  and  when  the  inner 
beak  of  the  forceps  is  placed  in  position  especial  care  must  be  used  to 
prevent  part  of  the  tongue  or  floor  of  the  mouth  from  being  caught  in 
the  instrument. 

THE  ORAL  OR  ANTERIOR  TEETH. 

(For  position  see  Fig.  546.) 

These  six  teeth  have  small  single,  straight,  compressed  roots.  Their 
extraction  is  only  necessary  Avhen  they  become  loosened  by  accident  or 
from  disease  or  when  it  is  necessary  to  clear  the  mouth  for  inserting 
artificial  teeth.  The  operator  should  stand  a  little  back  and  to  the 
right  side  of  the  chair,  being  somewhat  elevated  above  the  usual  posi- 
tion. Pass  the  first  finger  of  the  left  hand  between  the  lips  and  the 
alveolar  border,  and  place  the  remaining  fingers  beneath  the  chin  with 
the  thumb  on  the  inside  of  the  teeth.  For  the  incisors  use  the  lower 
root  forceps  shown  in  Fig.  499  or  the  universal  forceps  shown  in  Fig. 
489.  The  canines  are  larger  and  more  firmly  set  ;  delicate  root  forceps, 
therefore,  are  not  usually  suitable  ;  the  instrument  shown  in  Fig.  489 
or,  better,  the  bicuspid  forceps  (Fig.  497)  are  much  to  be  preferred. 

An  out-and-in  motion  is  proper  for  loosening  all  these  teeth. 

THE    BICUSPIDS. 

The  lower  bicuspids  have  compressed  roots  seldom  bifurcated,  and 
are  generally  extracted  by  the  out-and-in  motion.  The  special  forceps 
for  these  teeth  should  be  made  so  that  they  grasp  a  considerable  por- 
tion of  the  surface  of  the  tooth.  These  teeth  are  often  diflficult  to 
extract  without  breaking  when  all  the  teeth  are  in  position,  the  roots 
being  long  and  narrow  and  often  situated  in  an  awkward  position.  As 
shown  in  Fig.  518,  the  position  of  the  roots  of  the  second  bicuspid  is 
a  little  to  the  inner  side  of  the  anterior  root  of  the  first  molar.     The 


THE  LOWER   TEETH. 


607 


tooth   illustrated  in  this  particular  case  would  be  very  difficult  to  ex- 
tract  without  breaking. 

Fig.  546. 


Showing  position  for  extracting  lower  anterior  teeth. 


THE    FIRST    MOLAR. 

(For  position  see  Fig.  547  for  the  left  side,  Fig.  548  for  the  right 
side.) 

The  first  molar,  if  in  a  mouth  where  all  the  teeth  are  in  position,  is 
generally  the  most  difficult  of  all  the  teeth  to  extract.  The  roots  are 
usually  long  and  diverging.  It  is  lower  in  the  arch  than  the  other 
teeth,  and  is  in  fact  similar  to  an  inverted  keystone  ;  consequently, 
when  extracted  it  is  drawn  through  the  arch.  When  the  teeth  are  close 
together  the  second  bicus])id  and  second  molar  yield  a  little,  but  great 
care  must  be  taken  that  one  or  both  of  these  teeth  are  not  extracted 


608 


EXTRACTION  OF  TEETH. 


with  llic  lirst  inolnr.  In  placiiiji:  tlic  forceps  on  llic  lower  molars  the 
points  of  the  beaks  of  the  sjx'eial  molar  forceps  (Fig.  485  or  40<Sj  are 
placed  in  between  the  roots  on  each  side  of  the  tooth.  Care  should 
be  exercised  to  avoid  inelndino;  a  ])ortion  of  the  tono:ue  or  soft  tissues 
of  the  floor  of  the  mouth  in  the  force})s.  If  the  forceps  are  not  well 
placed  the  wrono;  tooth  may  be  extracted,  as  it  is  ])ossible  for  them  to 
slip  in  between  two  teeth. 

In  loosening  these  teeth  the  out-and-in  motion  is  used,  and  as  they  are 
wedged  in  it  is  often  necessary  to  continue  this  motion  while  extracting 
them  from  their  sockets.    At  times  it  is  advisable  to  move  the  tooth  out- 


showing  position  for  extracting  lower  teeth  of  the  left  side. 


wardly  after  it  has  been  slightly  lifted  from  its  socket.  Occasionally  the 
roots  diverge  so  far  that  either  the  crown  has  to  be  broken  from  the 
roots  at  their  bifurcation  or  the  tooth  divided  in  the  line  of  bifurcation 
with  splitting  forceps  ;  each  root  being  then  extracted  separately. 


THE    SECOND    MOLAR. 

The  roots  of  this  tooth  are  not  as  diverging  as  those  of  the  first 
molar,  as  may  be  seen  by  examining  Fig.  514,  nor  is  the  tooth  wedged 
in  as  tightly  as  in  the  case  of  the  first  molar. 

The  out-and-in  motion  is  required  for  these  teeth,  using  the  same 
precautions  that  are  necessary  in  the  extraction  of  the  first  molar. 


THE  LOWER   TEETH. 


609 


THE    THIRD    MOLAR. 

In  these  teeth  the  roots  may  vary  so  much  in  number  and  shape 
that  there  can  hardly  be  said  to  be  a  typical  third  molar.  Fig.  514 
shows  what  might  be  called  a  normal  third  molar,  but  these  are  only 
found  in  well-developed  jaws,  M'here  the  teeth  are  not  so  large  as  to 
cause  crowding.     They  vary  in  character  from  the  one  shown  in  Fig. 

Fig.  548. 


Showing  position  for  extracting  lower  teetli  of  the  right  side. 


514  to  the  two  shown  in  the  right  and  left  jaws  represented  in  Figs. 
5-30  and  531.  Figs.  526,  527,  528  and  529  show  other  forms  and  posi- 
tions of  the  third  molar.  There  are  also  third  molars  having  three, 
four,  or  five  roots,  o.  Fig.  534,  shows  another  form  of  the  third  molar; 
b,  c,  d,  e,  and  /  show  where  the  third  molar  has  united  with  the  second 
molar;  g  and  h  illustrate  three  molars  united;  j,  k,  I,  m,  n,  o,  and  jj  show 
variations  of  roots.  The  positions  these  teeth  occupy  may  vary  in  all 
degrees  from  that  shown  in  Fig.  514  to  those  shown  in  Figs.  525-531. 
Where  the  third  molar  is  in  the  position  shown  in  Fig.  514  and  there 
are  no  other  complications,  its  extraction  is  easy.  The  tooth  is  removed 
by  placing  either  the  special  lower  molar  forceps  shown  in  Fig.  498  or 
the  forceps  shown  in  Figs.  488  and  489  in  position,  and  using  the  out- 
and-in  motion  with  a  slight  raising  of  handles.     If  488  be  used  the 

39 


6'iO  EXTRACTION  OF  TEETH. 

beaks  should  be  turned  downward  and  the  handles  carried  upward. 
But  when  it  is  of  irregular  t'onn  and  position,  as  shown  in  the  various 
illustrations,  the  difficulty  increases  with  the  degree  of  variance  from 
that  of  the  normal  tooth  shown  in  Fig.  514.  These  cases  should  be 
closely  studied.  If  })ortions  of  the  teeth  are  in  view,  as  shown  in  Figs. 
530  and  o31,  they  will  assist  to  some  extent  in  the  diagnosis  of  the 
position  of  the  roots.  In  this  particular  case,  the  bone  as  well  as  the 
roots  being  much  hypertrophied,  it  would  be  impossible  to  extract  the 
roots  without  fracturing  the  process  to  a  greater  or  less  extent.  It  will 
be  noticed,  on  examining  the  section  Fig.  530,  that  to  have  fractured 
the  inner  portion  of  the  jaw  the  inferior  dental  nerve  and  vessels  and 
also  the  mylo-hyoid  nerv^e  and  vessels  would  be  endangered.  If  in 
attempting  to  extract  this  tooth  it  should  not  yield  to  a  pressure  which 
if  increased  would  break  the  bone,  it  is  better  to  desist  and  cut  away 
the  bone  with  a  bur  (shown  in  Fig.  587)  in  the  surgical  engine,  as 
was  done  in  the  case  of  the  specimen  from  which  the  illustration  was 
made.  Those  represented  in  Figs.  526,  527,  528,  and  529  would  be 
more  difficult  to  diagnosticate,  as  no  portion  of  the  teeth  is  in  view. 
If  trouble  existed  in  this  region,  the  explorations  would  have  to  be 
made  with  sharp  steel  probes.  The  bone  would  then  have  to  be  cut 
away  until  the  tooth  could  be  grasped  by  the  forceps,  the  forceps  shown 
in  Fig.  488  being  the  most  useful  for  this  purpose. 

In  Fig.  525  the  third  molar  is  in  such  position  as  to  be  easily  ex- 
tracted, though  if  proper  care  were  not  nsed  the  extraction  might  have 
.serious  consequences.  It  will  be  noticed  that  the  points  of  the  roots  are 
just  through  the  inner  U-shaped  cortical  portion  of  the  lower  jaw  below 
the  mylo-hyoid  ridge  and  project  into  the  submaxillary  region.  Now, 
should  this  tooth  or  the  roots  be  pushed  downward  in  attempted  ex- 
tracting, as  is  sometimes  taught,  it  might  be  forced  into  the  submaxillary 
region  and  consequently  be  lost  for  a  time,  with  the  possibility  of  having 
to  perform  a  subsequent  surgical  operation  to  cut  it  out  from  the  neck. 

An  impacted  third  molar  often  causes  great  distress  by  initiating  an 
inflammation  which  extends  to  the  region  surrounding  the  angle  of  the 
jaw,  and  often  including  the  temporo-maxillary  articulation  and  soft 
parts  within  the  mouth.  Under  these  conditions  the  jaws  can  only  be 
partly  opened,  deglutition  is  impaired,  and  solid  food  cannot  be  taken. 
One  of  two  things  must  be  done  :  either  the  offending  tooth  or  the 
one  in  front  of  it  must  be  extracted.  Every  effort  should  be  used  to 
extract  the  third  molar ;  if  any  part  of  the  tooth  can  be  seen,  the  diffi- 
culty is  not  so  great ;  the  inflammation  of  the  adjacent  parts  will  gen- 
erally quickly  subside.  As  the  mouth  can  only  be  opened  slightly, 
it  is  impossible  to  nse  the  large  special  molar  forceps.  An  elevator 
is  sometimes  recommended  in  these  cases,  but  it  may  prove  to  be  a 


TREATMENT  AFTER   EXTRACTION. 


Gil 


dano-erous  instrument  to  use  under  such  conditions,  for  when  the  tootli 
is  lifted  out  of  its  position  in  the  mouth,  it  mioht  easily  slip  back  into 
the  larvnx.  It  is  well  in  some  oases  to  loosen  a  tooth  Avith  an  ele- 
vator and  then  remove  it  with  the  foreejis  shown  in  Fiirs.  488  or  489, 


Fig.  549. 


Showing  the  direction  in  which  the  lower  third  molar  is  to  be  extracted. 

as  they  are  small  and  are  so  shaped  that  the  beaks  can  be  carried  back 
to  the  tooth  mainly  along  the  vestibule  of  the  mouth,  the  inner  blade 
beins:  placed  between  the  teeth  by  passing  the  forceps  back  of  the  second 
molar.  Often  it  is  impossible  to  see  completely  what  is  being  done, 
therefore  it  is  not  well  for  a  beginner  to  undertake  this  kind  of  extract- 
ing. After  the  force])s  is  in  })osition  the  tooth  should  be  worked  in 
any  direction  in  which  it  will  yield  ;  this  is  generally  outward,  upward, 
and  backward,  in  the  manner  of  unfastening  a  hook.  (See  Fig.  549.) 
When  the  third  lower  molar  is  impacted  near  the  angle  of  the  jaw,  it 
may  be  necessary  to  open  it  from  the  outside  through  the  soft  tissues. 
When  such  is  the  case  the  surgical  engine  should  be  used  for  cutting 
the  bone. 

Treatment  after  Extraction. 

The  operator  should  recognize  immediately  any  accident  that  may 
have  happened  during  the  operation  of  extraction,  and  ti'oat  it  as  the 
circum.stances  indicate  ;  l)ut  if  nothing  unusual  occurs,  then  the  patient 
may  be  allowed  a  few  moments'  rest,  after  which  the  mouth  should  be 
carefully  examined.  If  there  are  any  loose  portions  of  the  process  or 
pieces  of  gum  hanging  to  the  parts  operated  ui)on,  they  should  be  re- 
moved by  any  convenient  means,  such  as  a  curved  pair  of  scLssors  or 
a  curved  lancet  (Figs.  502  and  504). 

When  several  teeth  have  been  extracted  leaving  ragged  edges  of  the 
outer  walls  of  the  alveolar  process,  these  should  be  removed  with  the 


612  EXTRACTION  OF  TEETH. 

excising  forceps,  or  better  still,  by  the  use  of  either  forceps  Fig.  488  or 
489,  according  to  circumstances,  us  the  beaks  can  be  carried  between  the 
gum  and  the  process  better  than  can  the  blades  of  the  excising  forceps. 

An  antiseptic  mouth-wash  consisting  of  a  tablespoonful  of  phenol 
sodique  to  a  glass  of  water  should  be  used  several  times  daily  I'or  the 
next  few  days.  Any  other  suitable  antiseptic  mouth-wash  which  may 
be  more  agreeable  to  the  patient  may  be  used  instead,  though  the  jihcnol 
sodique  is  highly  efficacious. 

Occasionally,  in  a  few  days  after  extraction,  pain  will  be  noticed  in 
and  about  the  alveolus,  especially  when  the  tooth  has  been  the  seat  of 
pericemental  inflammation.  Relief  in  such  a  case  is  usually  given  by 
removing  any  clot  that  may  have  formed,  and  breaking  down  the  de- 
generated tissues  which  should  have  adhered  to  the  root.  A  pledget  of 
cotton  saturated  with  the  full-strength  solution  of  phenol  sodique  or 
camj)ho-phenique  should  then  be  inserted  as  a  dressing. 

Accidents. 

When  accidents  of  any  kind  whatever  occur,  the  operator  should  be 
calm  and  appear  perfect  master  of  the  situation.  He  should  be  pre- 
pared to  successfully  deal  with  whatever  conditions  may  arise. 

One  of  the  most  common  accidents  is  the  breaking  of  a  whole  or 
portion  of  a  tooth  or  root.  If  the  operator  has  any  doubt  of  his  ability 
to  remove  the  tooth  entire,  he  should  inform  the  patient  that  there  is  a 
possibility  of  its  breaking,  in  which  case  not  to  be  alarmed.  If  the 
tooth  is  removed  without  breakage  so  much  the  better ;  even  if  it  does 
break  it  will  not  cause  alarm  to  the  patient.  It  is  more  desirable  that 
all  of  a  tooth  should  be  removed,  for  if  its  surrounding  membrane  has 
been  inflamed,  or  if  a  root  has  been  broken  having  a  portion  of  the 
pulp  attached,  either  will  be  the  source  of  obstinate  pain. 

It  is  better,  however,  under  some  circumstances,  to  let  certain  roots 
remain  if  they  are  broken,  than  to  break  away  a  large  amount  of  process. 
Roots  are  sometimes  so  situated  that  they  can  be  easily  forced  into  the 
maxillary  sinus  (see  Figs.  516  and  517),  or  into  the  submaxillary  region 
(see  Fig.  525),  or  upon  the  inferior  dental  nerve.  If  there  are  good 
reasons  for  believing  that  the  root  will  not  cause  undue  pain,  and  there 
is  danger  of  breaking  a  large  amount  of  process,  it  is  preferable  to  let 
it  remain,  as  in  a  short  time  the  contraction  of  the  soft  parts  and  the 
expulsive  efforts  of  Nature  wuU  force  the  root  outward  and  it  can  then 
be  removed  without  danger.  If  roots  are  forced  into  the  maxillary 
sinus  they  must  be  followed  and  removed. 

When  several  teeth  are  to  be  extracted  under  an  anesthetic,  if  the 
gum  should  adhere  unduly  to  one  of  them,  the  operator  should  desist 
from  its  removal  and  proceed  with  the  other  extractions,  after  which 


ACCIDENTS. 


613 


the  adherent  gum  should  be  severed  with  a  curved  lancet  or  a  pair  of 
curved  scissors  and  the  tooth  then  removed.  If  the  gum  be  much 
torn  and  the  bone  exposed  to  a  great  extent,  it  should  be  held  in  place 
by  a  few  interrupted  sutures.  If,  however,  proper  care  is  taken  in  ex- 
tracting, this  should  not  occur. 

In  extracting  crowded  teeth,  or  those  having  frail  alveolar  surround- 
ings, it  is  possible  to  remove  a  piece  of  the  alveolar  plate,  especially  in 


Fig.  550. 


Fig.  551. 


Fig.  552. 


Fig.  553. 


Fig.  554. 


Fig.  555. 


Fig.  557. 


Fk;.  558. 


extracting  the  first  and  second  molars,  the  broken  piece  extending  back- 
ward, forward,  or  in  both  directions  to  the  adjoining  tooth.  (See  Figs. 
550  to  558.)  The  tooth  in  front  may  even  be  partially  lifted  from 
its  socket.  As  soon  as  the  operator  sees  the  impending  accident  he 
should  either  stop  and  see  if  his  method  of  extraction  could  be  im- 
proved, or,  this  point  being  negatively  decided,  hold  the  parts  in  posi- 
tion with  the  left  hand  as  well  as  he  can,  and  after  the  tooth  is  removed 
force  the  injured  parts  into  position  ;  they  will  usually  stay,  but  if  not, 
appliances  of  appropriate  form  can  be  used  for  retention. 

Ill  extracting  the  upper  third   molar,  the  tuberosity  is  sometimes 
broken  away,  opening  into  the  maxillary  sinus  (see  Figs.  550,  551,  552, 


614  EXTRACTION  OF  TEETH. 

5o'),  niul  558,  showiiiii^  wlicre  teeth  have  been  carried  away  with  the 
tiiherosity).  If  it  is  a  siin])le  fracture  the  parts  can  be  forced  into  phice 
and  they  will  in  a  short  time  reunite.  J)Ut  it"  the  i)arts  are  torn  h>ose  it 
will  be  of  little  use  to  try  to  rei)laee  them  ;  the  best  course  is  to  trim 
away  the  ragged  cdg(!S,  using  the  curved  scissors  for  this  purpose. 

After  such  a  fracture  it  is  possible  that  hemorrhage  may  occur  from 
rupture  of  the  superior  dental  artery.  This  is  sometimes  difficult  to 
control.  One  of  the  best  remedies,  however,  is  to  tightly  pa(!k  the  parts 
with  medicated  gauze.  This  application  must  be  left  in  for  a  few  days 
and  then  be  carefully  removed.  It  is  sometimes  well  to  take  out  only 
part  of  the  gauze  at  a  time,  the  loosened  portions  being  cut  off  with  a 
pair  of  curved  scissors.  Hemorrhage  after  extraction  usually  ceases  in 
a  short  time,  and  then  there  is  no  occasion  for  treatment ;  when,  how- 
ever, the  adjoining  parts  are  much  inflamed,  or  the  patient  is  in  an 
anemic  condition,  or  the  case  is  one  of  hemorrhagic  diathesis,  special 
treatment  will  be  necessary. 

Hemorrhage  of  extraction  may  be  divided  into  two  classes,  arterial 
and  capillary.  When  arterial,  it  is  nsually  located  in  the  socket  of 
the  tooth,  and  may  usually  be  stopped  without  much  difficulty  by  taking 
a  twist  of  absorbent  cotton,  shaping  it  into  a  thin  tapering  roll,  and 
thoroughly  packing  the  socket.  Before  inserting  the  cotton  tampon, 
it  should  be  rolled  in  tannic  acid  until  the  fibers  will  hold  no  more, 
then  the  cotton  is  to  be  packed  tightly  into  the  alveolus  with  a  dental 
plugger.  In  packing  the  cotton  it  is  well  to  begin  at  one  end  and 
crimp  it  upon  itself  until  the  socket  is  entirely  filled.  A  narrow  strip 
of  iodoform  gauze  when  packed  in  the  same  way  makes  a  good  plug, 
and  the  more  rapid  healing  of  the  parts  afterward  and  freedom  from 
any  offensive  odor  makes  it  a  more  satisfactory  tampon  than  the  tannic 
acid  and  cotton  plug,  though  the  styptic  quality  of  the  latter  makes  it  a 
more  efficient  hemostat.  The  plug  in  a  few  cases  may  require  retention 
in  position  by  compression.  This  is  accomplished  by  holding  a  few 
folds  of  muslin  or  similar  material  over  the  plug,  closing  the  mouth 
and  binding  the  jaws  together  with  a  few  turns  of  a  Barton's  bandage. 
(See  Figs.  559  and  560.)  The  25  percent,  ethereal  solution  of  hydrogerf 
dioxid  in  small  quantity  on  cotton  packed  into  a  bleeding  socket  is  a 
most  efficient  styptic,  and  will  effectually  control  severe  hemorrhage 
after  extraction.  Care  must  be  exercised  not  to  use  the  solution  in 
excess,  as  it  may  cause  injury  to  adjacent  parts. 

Where  hemorrhage  occurs  from  the  surrounding  tissue,  as  in  patients 
in  an  anemic  condition  or  in  cases  of  hemorrhagic  diathesis,  the  case 
usually  falls  into  the  hands  of  a  general  practitioner  for  systemic 
treatment,  but  the  local  treatment  usually  employed  by  physicians  in 
these  cases  is  often  unsatisfactory,  many  using:  Monsel's  solution  of 


ACCIDENTS.  615 

persulfate  of  iron,  which,  although  it  may  be  a  good  styptic  for  use  in 


Fig.  559. 


Fig.  560. 


Fig.  561. 


i;;irton's  head  bandage. 

other  parts  of  the  body,  should  not  be  used  in  the  mouth.  The  local 
treatment  in  such  cases,  whether  soon  after  extracting  or  not,  is  first 
to  remove  all  clots  from  the  wound  and  find  the  exact  place  or  places 
from  which  the  blood  is  exuding.  A  suitable  styptic  and  compression 
are  the  principal  means  used  for  stopping  it,  the  latter  perhaps  Ijeing 
the  most  important.  Tannic  acid  applied  on  cotton,  lint,  or  similar 
substances,  is  a  good  styptic  to  use  in  the 
mouth.  Iodoform  gauze,  for  the  reasons  al- 
ready given,  is  better,  although  it  has  not 
been  generally  used  in  tliis  connection.  Com- 
pression can  be  applied  as  the  ingenuity  of 
the  operator  may  direct.  When  a  hemor- 
rhage occurs  from  a  socket  between  good 
teeth,  it  can  be  readily  controlled  by  two 
ligatures,  making  one  fast  to  each  tooth,  then  placing  in  position  and 
tying  the  four  ends  together  over  the  compress,  as  shown  in  Fig.  5G1. 
In  a  few  rare  cases  an  impression  of  the  parts  should  be  taken  in  wax 
or  other  modelling  com})ound  in  order  that  a  rubber  or  metallic  j)late 
can  be  made  to  hold  the  styptic  compress  in  position.  After  the  com- 
press is  in  position  warmed  modelling  compound  can  be  placed  over  it 
and  the  jaws  brought  together  and  retained  in  place  by  a  head  bandage. 
A  plug  of  hardening  plaster  of  Paris  may  be  made  and  forced  into 
the  bleeding  socket  in  obstinate  cases,  or  in  exfrernis;  the  extracted  tooth 
miglit  be  soaked  well  in  phenol  sodique  and  reinserted. 

The  systemic  treatment  is  often  important ;  if  the  patient  is  seen 
to  be  anemic  or  known  to  be  of  the  hemorrha<ric   diathesis,  the  treat- 


showing  compress  and  ligatures. 


616  EXTRACTION  OF  TEETH. 

nient  slioiild  be  boguii  before  extra('tin<>;.  This  is  done  by  thoroughly 
building  up  the  system  by  a  course  of"  hygienic  and  tonic  treatment. 
The  cause  of  bleeding  in  cases  where  the  hemorrhagic  diathesis  exists 
is  but  imperfectly  understood  ;  the  blood  may  be  so  defibrinated  that  it 
has  lost  the  power  of  coagulation  and  so  will  not  form  a  clot,  or  the 
muscular  coats  of  the  vessels  have  lost  their  tonicity,  either  through 
general  debility  or  the  lack  of  energy  in  the  vasomotor  nervous  system, 
which  prevents  their  contracting  so  as  to  close  the  lumen.  Certainly 
the  walls  of  the  capillaries  permit  free  transudation  of  the  blood. 
In  good  health  the  proper  coagulation  and  the  contraction  of  the  blood- 
vessels will  stop  the  hemorrhage  even  when  an  artery  of  consider- 
able size  is  lacerated,  especially  if  the  flow  be  held  in  abeyance  by  arti- 
ficial means  for  a  short  time.  It  is  when  the  blood  will  not  coagulate 
and  the  vessels  fail  to  contract  that  a  thorough  systemic  treatment  must 
be  given.  This  lack  of  normal  function  on  the  part  of  the  blood  and 
vessels  may  arise  from  various  diseases,  and  in  order  to  judiciously 
treat  a  patient  exhibiting  the  hemorrhagic  diathesis  a  thorough  exam- 
ination must  be  made  and  such  treatment  given  as  the  diagnosis  indi- 
cates. Among  the  most  common  causes  of  hemorrhage  are  anemia, 
syphilis,  ]uirpura,  tuberculosis,  and  a  generally  impaired  vitality,  rarely 
an  over-acting  heart ;  the  passive  hyperemia  attendant  upon  a  weak 
heart  is  a  potent  fjictor  requiring  a  course  of  preliminary  treatment. 

Specific  and  special  diseases  must  of  course  receive  the  treatment 
peculiar  to  these  conditions.  On  general  principles  the  following  tonics 
are  advisable  :  Quassia,  cinchona  and  its  alkaloids,  iron  in  its  various 
forms,  sulfuric  and  hydrochloric  acids,  arsenic,  phosphorus,  nux  vomica 
and  its  alkaloid  strychnin.  With  these  general  tonics  various  hemo- 
statics can  be  given,  such  as  alum,  tannic  acid,  ergot,  erigeron  Cana- 
densis, and  gallic  acid.  Very  frequently  the  digestive  organs  require 
special  medication,  when  such  remedies  as  pepsin,  pancreatin,  hydro- 
chloric acid,  and  bismuth  subnitrate  are  indicated. 

The  following  prescriptions  have  proved  to  be  very  excellent  in 
their  special  province. 

As  general  tonics  : 

I^i.  Strychniffi  sulphatis, 

Acidi  arsenosi,  ««.  gr.  j  ; 

Quinise  sulphatis,  gr.  xxx  ; 

Ferri  suljihatis  exsiccat.,  gr.  xv. 

M.  et  ft.  pilula3  No.  xxx. 

S.  One  immediately  after  each  meal. 

^.  Elixir  ferri,  quinia?  et  strychnise,  foiv. 

S.  Teaspoonful  four  times  daily. 


USE  OF  GENERAL  ANESTHETICS.  617 

To  improve  digestion  and  assimilation  : 

I^.  Acidi  hydruc'hlorici  diluti,  f3ij  ; 

Ext.  ignatiie  amaris  fid.,  f^j  ; 

Pepsin,  3iss ; 

Ext.  ipeeaeuanhae  fld.,  ITtiv  ; 

Infusi  gentianffi  eomp.,  q.s.  ut  ft.  fovj. — M. 
S.  Dessertspoonful   in    sherry  glass   of  water   immediately  after 
meals. 

In  cases  of  undue  hemorrhage  after  extracting,  it  is  well  to  adminis- 
ter a  hemostatic  while  at  the  same  time  styptics  and  pressure  are  being 
applied  locally.     The  following  are  very  good  : 

R.  Vin.  ergota?  (Squibb's),  fsiij* 

S.  Teaspoonful  every  two  hours. 

I^.  Ext.  ergotse  solidificat.,  3j  ; 

Ext.  cannabis  indicse,  gr.  v  ; 

Strychnise  sulphatis,  gr.  ss. 

M.  et  ft,  pilulse  No.  xxx. 
S.  One  pill  three  times  a  day. 

Gallic  acid  and  aromatic  sulfuric  acid  may  ])e  administered. 

Digitalin  exhibited  in  doses  of  y\j-  to  -^  a  grain  three  or  four  times  daily 
for  a  series  of  weeks  will  often  effect  such  change  in  the  capillaries  as  to 
overcome  the  hemorrhagic  tendency.  This  has  been  repeatedly  and  suc- 
cessfully accomplished  in  epistaxis,  and  as  the  conditions  are  analogous 
it  can  be  employed  in  this  diathesis  with  expectation  of  similar  results. 

Extraction  under  the  Influence  of  General  Anesthetics. 

While  it  is  undoubtedly  true  that  the  extraction  of  teeth  under  the 
influence  of  a  general  anesthetic  is  in  accordance  with  the  general  spirit 
of  the  age  which  seeks  to  spare  all  suffering  or  cause  the  infliction  of 
but  slight  pain,  yet  many  evils  attend  such  general  and  too  often 
indiscriminate  use.  "  A  patient  under  the  effect  of  so  powerful  a 
drug  that  consciousness  is  destroyed  is  nearer  death  than  an  ordinary 
human  being,  since  the  jirimary  depressive  influence  upon  the  high 
nervous  centres  may  speedily  pass  to  the  lower  vital  centres  in  the 
medulla  oblongata."  ^ 

The  indiscriminate  use  of  general  anesthetics,  beside  their  possible 
danger  to  life  and  health,  has  an  accompanying  evil  in  the  demand 
for  the  extraction  of  teeth  which  are  salvable  and  useful,  but  Avhich 
'  H.  A.  Hare,  in  l\ir/c's  Text-Book  of  Surgery,  vol.  ii. 


618  EXTRACTION  OF  TEKTIL 

a  patient  insists  upon  liaving  removed  in  order  to  avoid  the  diseom- 
fort  attendant  upon  their  treatment  and  Idling-.  Xo  one  (piestions 
or  denies  the  enormous  beiietit  of  general  anesthetics  in  dentistry, 
i)artienlarlv  Avhen  painlul  operations  are  to  be  ])erformed  upon  ner- 
vous women  and  children,  but  if  the  patient  be  billing-  to  suffer  a  little 
pain  it  is  g;enerally  better  to  extract  M'ithout  a  j^eneral  anesthetic,  as  in 
that  case  the  patient  can  assist  the  operator  by  keeping  the  liead  in 
a  desired  position  Mith  the  mouth  and  lip.;  ^vell  open,  and  in  various 
other  ways,  while  under  the  influence  of  an  anesthctie  the  muscles 
supporting  the  head,  jaws,  and  cheeks  are  so  relaxed  that  it  io  difiicult 
to  keep  the  mouth  and  lips  well  open. 

If  the  operation  is  to  extract  a  difficult  tooth,  the  operator  is  limited 
to  the  time  when  the  patient  is  under  the  influence  of  an  anesthetic,  and 
in  the  case  of  nitrous  oxid  the  time  is  very  short ;  but  without  an  anes- 
thetic there  is  not  this  limitation  as  to  time,  and  the  extraction  may  be 
done  with  that  care  and  deliberation  essential  to  a  proper  operation.  It 
is  an  important  rule  in  any  Ijranch  of  surgery  that  the  time  required  to 
do  an  operation  must  l)e  sutficient  to  do  it  properly  and  without  un- 
necessary injury  to  the  adjoining  tissues. 

Examination  of  a  Patient  before  the  Administration  of  a  Gen- 
eral Anesthetic. — The  physical  examination  should  be  made  in  such  a 
way  that  it  will  not  cause  alarm  to  the  patient.  The  result  of  this  ex- 
amination governs  the  selection  of  the  anesthetic,  and  to  some  extent 
shows  how  far  the  patient  should  be  carried  under  its  influence.  It  has 
been  said  that  a  greater  amount  of  care  should  be  used  if  the  patient 
has  or  is  suspected  of  having  organic  or  functional  disease  of  either  the 
heart  or  the  lungs.  This  is  quite  true,  but  at  the  same  time  the  greatest 
amount  of  care  should  be  observed  in  all  cases.  For  the  physiological 
action  of  various  anesthetics  the  student  is  referred  to  special  works  on 
this  subject. 

The  question  often  arises  whether  anesthetics  should  be  used  at  all 
if  the  patient  has  either  organic  or  functional  disorder  of  the  heart. 
That  depends  to  a  large  degree  on  other  conditions  of  the  patient.  If 
the  shock  of  extraction  will  be  less  under  ether  or  nitrous  oxid,  then  by 
all  means  give  the  anesthetic  and  carry  the  patient  fairly  well  under  its 
influence,  so  that  there  will  be  neither  pain  nor  knowledge  of  the  ope- 
ration. Occasionally  patients  suffering  from  heart  disorders  can  bear 
a  certain  amount  of  pain  without  shock  ;  in  such  cases  it  is  better,  if 
the  operation  be  a  simple  one,  to  extract  while  in  the  normal  condition. 

The  use  of  ether  for  extracting  has  certain  advantages.  If  for  any 
reason  the  operation  requires  longer  time  for  its  performance  than  the 
influence  of  the  nitrous  oxid  will  last — say  from  one  to  two  minutes 
— it   is  better  to  use  ether.     Ether  can  be  given   after  the  patient   has 


USE  OF  GENERAL  AyESTHETICS. 


619 


become  anesthetized  by  nitrous  oxid  and  oxygen  and  he  may  be  kept  un- 
der its  iniiuenee  for  a  considerable  time  ;  in  this  wav  the  strutro'lin<>'  stao-e 
of  ether  is  avoided.  When  the  teeth  are  to  be  extracted  at  the  patient's 
liome  or  at  any  other  place  outside  of  the  office,  ether  is  more  conve- 
niently carried  than  nitrons  oxid.  If  properly  used  and  the  patient  has 
perfect  confidence  in  the  operator,  it  can  be  so  administered  that  one 
tAvo,  or  tln-ee  teeth  may  be  extracted  during  Avhat  is  known  as  the  first 

jTjQ  5g2.  ^^^^^  ^^  ^*'^^^'  anesthesia,   before  complete 

unconsciousness  and  long  before  the  strug- 
gling stage  commences. 

The  best  way  to  accomplisli  this  is  to 
administer  the  ether  in  a  cone  made  by  a 
napkni  or  towel,  with  the  small  end  slightly 
opened  s,,  as  to  allow  the  patient  to  inhale 
a  small  quantity  of  air ;  it  also  permits  the 
l)aticnt  to  exhale  freely  and  with  a  less  suf- 
focating effect.  It  is  well  to  place  in  the 
cone  a  small  soft  sponge  that  has  been  well 
washed  Mith  hot  water.  After  the  cone  is 
ready  the  patient  should  be  instructed  to 
breathe  several  long  and  full  inhalations ;  this 
clears  the  lungs  of  much  impure  air  and  ac- 
customs the  patient  to  the 
kind  of  breathing  required. 
Then  the  appliance  is  })laced 
in  front  of  and  some  distance 
from  and  above  the  month 
and  nose,  being  careful  to 
allow  none  of  the  ether  to 
drop  from  the  cone  upon  the 
face,  as  it  will  demoralize  the 
patient.  The  inhaler  is  to  be 
advanc(>d  toward  the  face 
slowly  and  gradually,  watch- 
ing the  effect  upon  the  pa- 
tient ;  if  there  is  a  tendency 
to  cough,  the  advance  should 
be  interrupted  until  this  lias 
passed.  After  the  cone  has  closed  tightly  over  the  mouth  and  nose, 
it  is  a  good  plan  to  ask  the  ])atient  to  hold  up  the  left  hand  as  long 
as  possible  ;  this  will  concentrate  his  thoughts  upon  the  act  and  aM'ay 
from  the  operation.  When  the  hand  begins  to  fall,  the  request  to  raise 
the  hand  should  be  repeated  ;    it  will  soon  fall,  and  in  a  few  seconds 


Nitrous  oxid  gasometer. 


620 


EXTRACTION  OF  TEETH. 


afterward  one,  two,  or  three  teeth  may  be  removed,  the  nuiuber  de- 
pendiiitj;  entirely  upon  their  position  and  the  dilKeulty  to  he  overeome 
in  their  extraction.  As  soon  as  the  teeth  are  extracted  the  head  of 
the  patient  sh(»ul(l  l)e  raised  from  the  head-rest  and  the  l)ody  carried 
forward,  and,  having  a  hand  euspi(h)r  in  front,  the  patient  slionld  be 


Fig.  563. 


—  _.  Water  line 


To  gas  cylinder 


Sectional  view  of  gasometer. 


requested  to  eject  the  blood  from  the  mouth  ;  this  direction  is  usually 
complied  with.  The  patient  in  most  instances  recovers  in  a  few 
moments  and  with  no  disagreeable  after-effects,  but  if  the  ether  is 
carried  beyond  the  struggling  stage  to  the  point  of  complete  sur- 
gical narcosis  the  nauseating  after-eflPects  are  very  disagreeable  unless 
the  patient  has  been  thoroughly  prepared  for  the  occasion. 

Nitrous  oxid  is  the  anesthetic  most  commonly  administered  for  the 


USE  OF  GENERAL  ANESTHETICS.  621 

extraction  of  teeth,  and  under  ordinary  circumstances  is  the  best.  Until 
lately  every  operator  was  his  owu  maker  of  the  gas — this  was  a  great 
disadvantage — but  now  it  can  be  procured  in  a  liquefied  form  com- 

FiG.  564. 


Nitrous  oxid  inhaler. 


pressed  in  cylinders.  There  are  many  different  appliances  used  for 
the  administering  of  this  gas  even  when  using  it  in  a  condensed  form. 
One  of  the  most  prominent  is  that  shown  in  Figs.  5G2  and  563,  in 


622 


EXTRACTION  OF   TEETH. 


wliieli  tlie  _o:as  is  drawn   into  a  reservoir  and  tlien  passes  through  a  flex- 
ible tube  to  the  ni(»iitli-j)iece  (Figs.  564  and  /3G5). 


Fig.  565. 


Hood  inhaler. 


The  two  principal  mouth-pieces  are  Fig.  564,  which  should  have 
the  detachable  lip-shield  removed  so  that  the  tube  may  be  placed 
directly  into  the  mouth  and  the  lips  compressed  around  the  tube  by 
the  operator,  at  the  same  time  closing  the  nostril  by  the  thumb 
and   finger,  and   Fig.  565,  which   is  known   as  a  hood   inhaler;   it  is 


USE  OF  GENERAL  ANESTHETICS. 


623 


Fig.  566. 


Stand  for  compressed  gas  cylinder,  gas  bag,  tube,  and  inhaler. 


624 


EXTRACTION  OF  TEETH. 


made  to  cover  the  nose  as  well  as  the  mouth.  The  advautafi^e  of  the 
first  mouth-piece  is  that  the  lips  may  be  closely  watched  I'or  the  change 
of  color  denoting  oxygen-starvation  of  the  blood,  which  the  experienced 
operator  combats  by  admitting  a  certain  amount  of  air  with  the  gas  as 
required.  Fig.  567  represents  a  portable  appliance  to  be  used  at  a 
patient's  home  or  away  from  the  regular  office. 

Fig.  567. 


Portable  nitrous  oxid  apparatus. 


Dr.  Hewitt's  Method. — Dr.  Frederick  Hewitt  of  London,  England, 
has  devised  the  apparatus  shown  in  Figs.  568  and  569.  The  three 
cylinders  contain  the  compressed  gas,  two  being  filled  with  nitrous  oxid 
and  one  with  oxygen.  The  valves  of  the  cylinders  are  opened  by  a  key 
which  is  controlled  by  the  foot  of  the  operator.  The  tube  passing  from 
the  cylinders  to  the  receiving-bag  is  double,  a  smaller  tube  being  placed 
within  the  outer  larger  tube.  The  receiving-bag  is  also  double,  being 
divided  by  a  rubber  septum  into  two  compartments  W'hich  have  their 
outlet  in  the  double  tube  which  leads  to  the  inhaler.  To  the  receiving- 
bag  is  attached  a  mixing-chamber,  and  to  this  the  inhaling-tube  or  hood 
is  fastened.  This  appliance  is  used  very  successfully  in  England  and 
has  been  introduced  into  the  United  States.  It  has  proved  satisfactory 
to  all  who  have  tried  it.  The  bags  and  tubing  should  be  made  of 
more  durable  material  when  intended  for  use  in  the  American  climate. 


USE  OF  GENERAL  ANESTHETICS. 


625 


The  manner  in  which  the  appliance  is  used  is  as  follows  :  The  valves 
in  the  mixing-chamber  (Fig.  569)  are  closed,  then  oxygen  is  let  into  its 
compartment  of  the  receiving-bag  until  the  latter  is  nearly  filled,  when 
the  nitrous  oxid  is  admitted  into  its  compartment.  The  patient  being 
prepared,  the  inhaling-tube  or  hood  is  placed  in  position,  and  the 
patient  is  directed  to  breathe — long,  full,  and  steadily.  If  the  tube  is 
used  it  is  necessary  to  close  the  nose  by  the  thumb  and  finger. 


Fig.  568. 


Complete  apparatus  of  It.  Ik'Witt  for  administering  mixed  nitrous  oxid  and  oxygen. 

The  valves  are  not  changed  for  a  few  inhalations,  during  which  time 
only  air  is  inhaled  ;  then,  pressing  the  indicator  a  downward  to  the  first 
notch  Ij,  the  air  is  cut  off,  and  the  patient  receives  pure  nitrous  oxid  ; 
this  is  allowed  for  a  few  more  inhalations,  and  then  the  indicator  is  car- 
ried to  the  next  notch  and  one  part  of  oxygen  is  allowed  to  pass  into 
the  respiration.  When  the  indicator  is  carried  to  the  third  notch  two 
parts  are  received  by  the  patient,  and  so  on  until  the  maximum  amount 
of  oxygen  required  by  the  patient  has  been  reached. 

It  has  been  found  by  careful  study  of  many  thousands  of  cases  and 
by  special  scientific  investigation  that  the  asphyxial  condition  incident 
to  most  cases  of  nitrous  oxid  inhalation  is  quite  unnecessary  to  the  pro- 

40 


626 


EXTRACTION  OF  TEETH. 


diictioii  of  nitrons  ox  id  uiu'stlu'sia.  It  is  also  justly  considcrccl  to  be 
siihjccting-  a  patient  to  an  unwarrantahlc  (lant;vr  to  permit  the  asphyxia] 
oH'cct  to  manifest  itself  to  a  profound  degree,  as  in  many  eases  it  is 
a  menace  to  life  and  liealtli,  and  might  have  a  fatal  effect.  The  object 
of  Dr.  Hewitt's  method  is  t(j  control  or  eliminate  the  asphyxial  clement 
by  administering  a  requisite  amount  of  oxygen. 

Fig.  569. 


Showing  arrangement  of  the  mixing-chamber,  with  dial  and  valve  for  controlling  the 
relative  proportions  of  the  gases. 

No  fixed  rule  can  be  laid  down  for  the  quantity  of  oxygen  to  be 
added,  as  each  case  will  require  a  different  amount  and  this  amount 
varies  during  the  several  stages  of  the  anesthetic  procedure.  The 
operator  is  guided  entirely  by  the  symjitoms  of  the  patient  during  the 
administration,  his  object  being  to  avoid  on  the  one  hand  the  tendency 
toward  asphyxia  indicated  by  cyanosis  of  the  lips,  and  return  of  con- 
sciousness and  sensation  on  the  other  hand,  which  is  easily  produced 
by  an  excess  of  oxygen.  By  the  admixture  of  oxygen,  as  in  Dr. 
Hewitt's  method,  the  anesthesia  is  somewhat  prolonged  over  the  ordinary 
nitrous  oxid  method  and  is  slower  of  induction,  but  there  is  entire 
absence  of  cyanosis,  stertorous  breathing,  jactitation,  or  any  of  the 
symptoms  of  asphyxia.  The  modification  of  the  Hewitt  apparatus 
that  has  been  lately  introduced  embodies  certain  features  that  make  it 
an  improvement  on  the  original  apparatus.  The  arrangement  of  the 
mixing-chamber  in  reference  to  the  bags  containing  the  gases  is  such  as 
to  enable  the  operator  to  more  accurately  control  the  mixture  that  is 


USE  OF  GENERAL  ANESTHETICS. 

Fig.  570. 


627 


Apparatus  for  admini.steriiis  nitrous  oxid  and  oxygen  combined:  a,  key  to  oxygen  bag;  b,  key  to 
oxygen  cylinder;  c,  gauge  showing  percentage  of  oxygen  being  administered,  d,  mixing- 
chamber  ;  c,  key  to  nitrous  oxid  cylinder ;  /,  key  to  nitrous  oxid  bag. 


628  EXTRACTION  OF  TEETH. 

administered  to  the  patient.  J>y  a  turn  of  tiic  levers  r/  and /(Fig.  570) 
any  gradation  of"  the  gases  may  be  obtained,  from  jiiire  nitrons  oxid  on 
the  one  iianil  to  pure  oxygen  on  tlie  other.  Tiie  eonstruction  of  the 
apj>aratus  is  such  as  to  better  withstand  the  climatic  conditions  than  the 
Hewitt  ai)paratns.  A  brief  description  will  suffice  to  show  the  working 
of  the  apparatus. 

There  are  two  cylinders,  one  containing  compressed  nitrous  oxid  and 
the  other  compressed  oxygen. 

Two  bags,  one  of  black  material  containing  the  nitrous  oxid,  the 
other  of  red  material    containing  the  oxygen. 

The  key  to  each  cylinder  (see  b  and  c)  opens  the  valve  and  allows 
the  gas  to  pass  into  its  respective  bag. 

By  opening  the  valve  (see  /)  of  the  nitrons  oxid  bag  the  gas  passes 
into  the  mixing-chamber,  from  which  it  flows  through  the  covered  rub- 
ber tube  to  the  inhaler. 

When  it  is  desired  to  combine  oxygen  with  nitrous  oxid,  open 
gauged  valve  (see  a,  c)  to  the  oxygen  bag ;  this  will  admit  the  oxygen 
into  the  mixing-chamber.  Both  gases  Avill  pass  through  the  tube  to 
the  inhaler. 

The  proportion  of  oxygen  used  will  be  determined  by  the  degree 
to  which  the  gauged  valve  is  opened. 

By  closing  the  valve  of  the  nitrous  oxid  bag,  oxygen  can  be  given 
separately. 

Similar  results  are  obtained  w'hen  air  is  admitted,  instead  of  oxygen, 
to  the  patient  during  the  nitrous  oxid  administration.  The  details  of 
this  procedure  are  set  forth  in  the  following  chapter. 


CHAPTER    XXI.   (Continued). 

EXTRACTION  OF  TEETPI  UNDER  NITROUS  OXID 
ANESTHESIA. 

By  J.  D.  Thomas,  D.  D.  S. 


Where  the  operation  would  cause  excessive  pain,  the  extraction  of 
a  tooth  without  the  aid  of  an  anesthetic  is  to-day  little  short  of  bar- 
barous. It  is  cruel  to  the  patient,  and  if  the  subject  be  a  child, 
wantonly  so.  Very  few  people  can  submit  to  the  operation  without 
more  or  less  physical  resistance,  and  even  though  this  be  involuntary 
no  operator  can  do  full  justice  in  such  a  case,  no  matter  how  skillful  he 
mav  be.  kSucli  resistance  causes  more  or  less  unnecessary  strain  to  be 
applied  in  one  direction  or  another  against  the  process,  which  results  in 
increased  inflammation  as  a  sequence.  Besides,  as  a  rule  the  liability 
of  breaking  the  tooth  or  portions  of  the  alveolar  plate  or  other  accidents 
is  increased  a  hundredfold. 

Nitrous  oxid  is  in  all  respects  the  very  best  anesthetic  for  the  pur- 
poses of  the  dentist.  Properly  used,  it  is  almost  entirely  free  from 
danger  and  is  rarely  productive  of  nausea  or  depression  as  an  after- 
effect, even  temporarily.  It  seldom  requires  over  sixty  seconds  to  pro- 
duce anesthesia,  and  in  less  than  that  period  of  time  the  patient  is 
fully  recovered,  with  no  knowledge  of  the  operation,  and  is  ready  to 
depart  as  soon  as  bleeding  ceases.  To  accomplish  such  a  result,  of 
course,  requires  experience  and  some  degree  of  dexterity,  but  the  con- 
ditions are  such  that  any  dentist  with  a  fair  amount  of  experience  can 
operate  successfully  with  it  for  the  removal  of  from  one  to  four  or  five 
teeth,  and  perhaps  more — the  main  essential  in  operating  by  the  aid  of 
nitrous  oxid  being  to  utilize  every  second  of  time  during  the  period  of 
anesthesia,  and  not  to  waste  it  in  hunting  forceps  or  deciding  how  they 
should  be  used. 

The  best  success  is  o1>taincd  by  formulating  a  system  of  working  by 
which  one  can  accomplish  the  most  in  the  shortest  space  of  time.  The 
operating  period  seldom  extends  over  forty-five  seconds  and  often  less, 
so  that  every  second  wasted  in  any  way  whatever  is  so  much  time  lost, 
and  success  is  diminislied  to  just  that  extent. 

Nitrous  oxid  must  be  absolutely  jiurc,  and  if  l)e  kept  over  water  it 

629 


630  EXTRACTION  OF  TEETH   UNDER  NITROUS  OX  ID. 

must  be  fresh.  In  fonucr  times  when  the  dentist  nianul:ietnre(l  liis  own 
gas,  to  insure  i)ertect  purity  it  was  necessary  to  test  the  ammonia  nitrate 
before  using  it  for  making  tlie  nitrous  oxid,  but  at  the  present  day  the 
pure  gas  is  made  with  great  accuracy  by  the  manufacturers  and  is 
supplied  chemi(!ally  pure,  compressed  in  cylin(U'rs,  so  that  the  individ- 
ual dentist  is  relieved  of  the  responsibility  of  manufacturing  his  own 
gas  and  of  the  troubles  necessary  to  secure  purity. 

The  first  essential  to  success  in  its  administration  is  a  perfect 
INHALER.  This  should  be  sufficiently  large  to  permit  the  patient  to 
breathe  without  the  slightest  exertion.  Patients  are  always  in  a  more 
or  less  nervous  state  upon  approaching  the  dental  chair  for  extraction. 
There  is  usually  accelerated  heart-beat  and  consequently  deranged 
respiration,  and  unless  they  can  breathe  through  the  inhaler  with  per- 
fect freedom  they  labor  under  a  sense  of  suffocation  which  adds  greatly 
to  their  apprehension  and  disturbs  their  equanimity  while  passing  under 
the  influence  of  the  anesthetic. 

The  inhaler  shown  in  Fig.  565  is  perhaps  the  best  one  upon  the 
market,  but  has  the  disadvantage  of  having  hard  disk  valves,  and 
while  the  size  is  sufficiently  large  for  most  purposes  the  space  between 
the  outer  circumference  of  the  disk  and  the  inner  circle  of  the  pipe  is 
so  small  that  it  does  not  at  all  times  permit  of  free  ingress  of  the  gas 
to  the  lungs,  and,  besides,  such  valves  are  not  always  airtight. 

The  best  inhaler  is  one  made  of  vulcanized  rubber  turned  to  the 
proper  dimension  and  fitted  with  valves  made  of  rubber  dam  (Fig. 
571).     These  valves  have  the  property  of  fitting  closely,  making  the 

Fig. 571. 


Thomas's  inhaler. 


passages  airtight,  and  being  flexible  they  admit  the  gas  to  the  lungs 
^vith  little  or  no  obstruction.     This  inhaler  is   the  one  employed  by 


ADMINISTRATION  OF  NITROUS  OXID.  631 

most  operators  who  make  a  specialty  of  extraction,  and  is  made  only 
upon  special  order. 

In  ffivino;  nitrous  oxid  it  is  necessary  that  the  valves  of  the  inhaler 
shall  be  airtight,  for  if  there  is  a  leakage  by  which  air  is  constantly 
being  admitted,  it  will  interfere  greatly  with  the  production  of  the 
desired  results.  The  hood  face-piece  should  never  be  used.  Aside  from 
the  impossibility  of  fitting  the  face  so  closely  as  to  preclude  the  admis- 
sion of  some  air  during  the  administration,  particularly  when  beard 
exists,  it  covers  the  lips  from  view,  and  these  are  an  important  index 
during  the  process  of  anesthesia ;  the  color  of  the  l)lood  as  shown 
tiirough  the  mucous  membrane  of  the  lips  should  never  be  lost  to 
sight. 

There  is  no  separation  of  the  elements  of  nitrous  oxid  at  the  tem- 
perature of  the  human  body,  or  during  its  inhalation,  consequently  it 
is  jn-actically  an  inert  gas  so  far  as  its  power  to  support  life  is  con- 
cerned. It  possesses  strong  anesthetic  properties  but  it  is  also  to  a 
degree  productive  of  asphyxia,  and  the  color  of  the  lips  must  be  ob- 
served as  a  guide  to  indicate  the  extent  to  which  asphyxia  is  taking 
place.  It  has  been  previously  said  that  the  valves  of  the  inhaler  must 
be  airtight,  for  a  constant  leakage  of  air  will  prevent  the  production 
of  complete  anesthesia,  and  yet  at  the  proper  time  during  the  inhala- 
tion the  admission  of  air,  controlled  by  opening  the  nose  or  raising  the 
lips,  is  not  only  desirable  but  essential  to  the  proper  and  successful  ex- 
hibition of  the  anesthetic. 

By  the  judicious  admission  of  air  at  the  proper  time  the  accompany- 
ing symptoms  of  approaching  asphyxia  are  obviated  and  perfect  anes- 
thesia is  secured  without  any  of  the  convulsive  muscular  twitching 
which  takes  place  when  the  pure  gas  is  given.  Dr.  Hewitt  of  London 
advocates  the  admixture  of  oxygen  with  nitrous  oxid,  for  which  he  has 
introduced  the  appliances  described  on  p.  624,  but  by  admitting  air  as 
here  suggested  similar  results  are  obtained  with  less  manipulation. 

The  use  of  props  to  keep  the  jaws  open  is  necessary  to  insure  success. 
They  give  free  scope  for  operating,  and  there  is  no  time  lost  in  prying 
the  mouth  open,  as  nearly  always  happens  when  props  are  not  used. 
Props  made  of  hard  wood  and  of  different  sizes  are  the  most  satisfactory ; 
thev  should  have  strings  attached,  more  to  reassure  the  patient  than 
for  any  other  reason.  Unfortunately,  a  number  of  years  ago  a  patient 
died  as  a  result  of  getting  a  cork  in  the  larynx,  and  this  has  never  been 
forgotten.  Consequently  the  string  is  an  assurance  to  the  patient  that 
the  prop  cannot  slip  down  the  tliroat. 

The  ordinary  dental  chair  is  not  desirable  for  use  in  administering 
nitrous  oxid,  particularly  those  chairs  having  stationary  footstools  at- 
tached.    Patients  are  sometimes  restless,  and  every  motion  made  by  the 


(132  EXTRACTION  OF  TEETH    UNDER   NITROUS  ON  1 1). 

l(('t  ii|)()ii  :i  fixed  footstool  will  produce  a  responsive  movement  of  the 
body,  tlicrchy  increasing  the  risk  of  accident  to  th(>  j);irt  being  operated 
upon.  A  detached  stool  upon  casters  is  easily  pushed  away,  so  that 
any  disposition  to  move  tiie  extremities  may  he  permitted  without 
ailectiug  the  stability  of  the  up})er  part  of  the  body. 

This  apparent  n^sistance  on  the  part  of  the  patient  is  not  necessarily 
the  indication  of  a  knowlcdox'  of  what  is  being  done  ;  the  upper  brain 
function  may  be  paralyzed  while  tiie  sensory  ])eripherals  and  motor 
ganglia  are  not,  under  which  circumstances  the  patient  is  not  thoroughly 
anesthetized.  Resistance  may  take  place  at  the  beginning  or  just  at  the 
termination  of  the  anesthetic  procedure,  and  if  the  operator  ceases  at 
once  the  patient  will  declare  absolute  unconsciousness  of  the  operation. 
It  is,  however,  sometimes  permissible  to  operate  during  the  stage  just 
noted  in  cases  where  the  systemic  conditions  are  such  that  it  would  be 
unwise  to  carry  the  patient  to  the  state  of  profound  insensibility.  These 
are,  howev(!r,  exceptions  and  not  the  rule.  To  have  the  exhibition  per- 
fectly satisfactory  there  should  be  no  resistance  or  outcry. 

A  competent  a><><i4ant  is  necessary,  not  onl}-  as  a  protection  against 
charges  which  might  be  suggested  by  lascivious  dreams — as  has  occurred 
when  ether  has  been  employed  (though  the  period  of  insensibility  under 
nitrous  ox  id  is  so  short  that  it  would  seem  that  no  one,  however  evilly 
or  honestly  disposed,  could  ever  sustain  such  a  charge) — but  an  assist- 
ant can  render  much  aid  by  holding  the  tube,  lowering  or  raising  the 
head,  taking  care  that  the  operator  does  not  bruise  the  lips,  holding  the 
patient  if  restless,  particularly  the  hands,  and  waiting  upon  the  patient 
during  recovery  from  the  anesthetic. 

The  assistant  should  be  a  woman,  as  it  adds  very  materially  to  the 
comfort  of  female  ])atients  to  have  such  a  person  in  attendance. 

The  operator  should  receive  the  patient  in  such  a  manner  as  to 
inspire  entire  confidence.  If  necessary,  any  doubts  or  possibilities  of 
accident  should  be  clearly  explained  to  the  ]iatient,  so  that  in  the  event 
of  untoward  results  there  will  not  be  a  humiliating  sense  of  failure. 

The  patient  is  seated,  and  after  a  careful  examination  has  been  made 
and  the  condition  of  the  tooth  or  teeth  is  ascertained,  the  prop  is  placed 
where  it  will  be  least  in  the  way.  The  assistant  then  places  the  tube 
in  the  mouth  and  the  patient  is  directed  to  close  the  lips  and  breathe 
through  the  mouth  instead  of  the  nose  ;  in  the  meantime  closing  the 
nostrils  with  the  third  finger  and  thumb  of  the  left  hand,  the  first  and 
second  pressing  the  upper  lip  about  the  mouthpiece,  while  the  thumb 
and  fingers  of  the  right  hand  support  the  lower  lip. 

While  inhaling  the  gas  it  is  desirable  that  patients  should  breathe 
as  in  ordinary  respiration,  for  two  reasons  :  First,  if  instructed  to  take 
long  and    deep  breaths    they  exert   themselves   beyond    their    natural 


THE  OPERATION   OF  EXTRACTION.  633 

rlivtlim,  aud  with  unconsciousness  comes  involuntary  suspension  for  some 
seconds,  and  should  it  occur  in  one  who  becomes  quickly  asphyxiated 
the  few  seconds  of  suspension  are  sufficient  to  produce  alarming  symp- 
toms which  will  require  some  etfort  to  counteract.  Second,  if  the 
patient  breathe  slower  or  less  deeply  than  is  natural  there  is  a  sense 
of  suiFocation  produced  which  grows  in  intensity  until  unconscious- 
ness supervenes,  when  the  lungs  and  diaphragm  will  exert  tiieir  func- 
tion, producing  violent  respiratory  effort  which  will  be  follo^\-ed  by 
marked  exhaustion  upon  recovery.  Xone  of  these  effects  need  be 
priKluced  if  the  operator  have  complete  control  of  the  situation. 

Xo  one  can  explain  the  symptoms  of  approaching  and  complete 
anesthesia  in  such  a  manner  as  will  inform  a  novice  sufficiently  well  to 
undertake  the  responsibility  of  administering  the  gas ;  these  can  only  be 
learned  through  observation  and  experience,  but  the  first  prominent 
indication  will  be  a  discoloring  of  the  lips  and  subsequent  pallor  of 
countenance,  which  is  not,  however,  an  indication  of  cardiac  depres- 
sion, but  is  due  to  the  blood  color  shoAvn  through  the  skin.  Should 
the  patient  be  of  the  blonde  and  florid  type  this  appearance  will  be 
more  marked,  and  it  is  here  that  the  admission  of  a  small  amount 
of  air  is  called  for,  particularly  if  the  blueness  seems  to  approach 
more  rapidly  than  the  anesthesia. 

If  the  pure  gas  is  given  to  complete  narcosis,  there  will  be  twitching 
of  the  muscles  of  the  neck  and  wrists.  Stertor  and  irregular  breathing 
and  sometimes  decided  convulsive  action  occur,  which  to  one  inexperi- 
enced becomes  distressing,  if  not  alarming,  to  behold. 

All  these  symptoms  are  at  once  relieved  by  air-breathing,  and  if 
there  is  a  judicious  admission  of  air  during  the  administration  of  the 
anesthetic  they  will  be  avoided  entirely. 

The  patient  being  anesthetized — and  the  instruments  being  always  in 
place  so  that  there  will  be  no  delay  in  picking  up  the  i)air  of  forceps 
required,  so  that  every  second  of  time  may  be  utilized  by  the  work 
in  hand — the  next  step  is  the  extraction. 

The  Operation  of  Extraction. — The  proper  Avay  to  perform  the 
operation  is  to  stand  in  one  position,  at  the  right  side  of  the  patient, 
durino^  the  whole  proceeding;.  For  extractino-  with  the  greatest  facility 
the  operator  should  assume  such  a  position  that  in  standing  erect  the 
patient's  head  will  be  about  opposite  his  upper  waistcoat  pocket.  To 
do  this  a  pair  of  stools  should  be  used,  one  just  back  of  the  chair  and 
one  by  the  side  Avhich  may  be  easily  pushed  aside  when  not  needed. 
While  administering,  the  operator  can  stand  upon  the  floor,  and  ascend 
the  stool  just  before  the  time  for  operating.  This  position  is  assumed 
by  the  most  successful  operating  specialists,  and  is  adopted  as  the  residt 


634  EXTRACTION  OF  TEETH   UNDER  NITROUS  OX  ID. 

of  l(MiL!;  ('X)>(>ri(Mi('(»  and  dictated  by  the  desire  to  hriiii^  uhout  a  ])()sition 
for  work  wiiieli  permits  of  its  most  rapid  performance  and  at  tiie  same 
time  enables  the  ()i)erator  to  bring  to  bear  tlie  greatest  amount  of  force 
with  the  least  physical  exertion. 

When  extracting,  for  exam])le,  a  lower  tooth,  and  it  is  necessary  to 
force  the  beaks  of  the  forceps  well  down  through  the  process,  the 
instrument  is  nianij)ulated  by  the  hand  and  wrist  with  the  arm  held 
closely  to  the  body  to  steady  it.  The  weight  of  the  body  is  allowed  to 
descend  to  the  pi'oper  degree  by  bending  the  knees,  and  when  the  for- 
ceps are  fixed,  should  force  for  pulling  be  required,  the  straightening  of 
the  knees  will  raise  the  body,  the  arm  being  held  firmly  as  described. 
The  hand  will  be  used  exclusively  for  manipulating  and  guiding,  w^hile 
the  force  will  be  supplied  by  straightening  the  knees  much  the  same  as 
is  applied  in  lifting  weight  from  the  ground.  Of  course,  to  become 
expert  one  must  have  all  of  his  limbs  equally  trained. 

In  operating  on  the  upper  jaw  the  method  is  much  the  same,  only 
reversed,  bending  the  knees  first  to  lower  the  body  and  forcing  the 
instrument  to  position  by  straightening  and  throwing  as  much  of  the 
bodily  weight  upon  the  arm,  by  bending  the  knees,  as  is  necessary  for 
pulling.  By  so  doing  a  tooth  will  never  be  allowed  to  leave  the  socket 
suddenly  as  by  a  jerk,  for  the  operator  has  perfect  control  of  his  hand 
and  wrist,  and  the  danger  of  bruising  the  opposite  teeth  in  either  jaw^  by 
the  forceps  is  avoided. 

The  Forceps. — Seven  pairs  of  forceps  are  all  that  are  used  by  the 
writer  for  extraction  in  ordinary  cases.  For  the  upjier  teeth,  a  right  and 
left  pair  for  the  molars,  a  bayonet-shaped  instrument  with  the  outer  beak 
pointed  to  fit  between  the  buccal  roots,  and  both  beaks  serrated.  In 
working  upon  both  sides  of  the  mouth  a  pair  without  pointed  beaks  may 
be  used  with  advantage  to  avoid  changing.  One  alveolar  pair  suffices 
for  the  roots  of  all  molars  and  bicuspids  on  either  side.  These  are 
made  bayonet-shaped  with  smooth  concave  beaks,  but  having  well 
sharpened  edges.  The  pair  for  the  incisors  is  straight,  with  beaks  simi- 
lar to  the  alveolar  pair,  and  when  extracting,  say  all  the  upper  teeth, 
can  be  used  upon  all  ten  front  ones  with  equal  facility. 

For  teeth  in  the  lower  jaw  the  molar  pair  is  made  with  both  beaks 
pointed,  serrated,  and  gracefully  curved  so  as  to  bring  the  force  as  nearly 
direct  as  possible;  these  are  equally  applicable  for  all  the  molars  on 
either  side  and  are  shaped  the  same  as  the  alveolar  pair.  The  alveolar 
pair  are  shaped  the  same  as  those  for  the  molars,  have  smooth  concave 
beaks  with  sharp  edges,  and  are  used  fir  all  molar  roots  and  bicuspids 
(Fig.  572).  Tlie  pair  for  front  teeth  is  curved  under  the  handle  and 
may  have  serrated  beaks,  as  the  roots  of  the  lower  centrals  and  laterals 


THE  OPERATION  OF  EXTRACTION. 


635 


Fig.  572.  are  SO  flat  that  a  sharp  beak  is  apt  to  cut 

them  off,  if  too  much  grasp  is  applied. 
Tliey  seklom  require  the  force  necessary 
iu  the  extraction  of  other  teeth. 

The  writer  prefers  forceps  that  are  not 
nickel-phited,  as  tiiis  imparts  a  slippery 
or  ''greasy  "  feeling  to  the  handle,  making 
the  hold  less  secure,  which  induces  an 
increase  of  force  in  the  operator's  grasp,  with 
greater  liability  of  cutting  or  crushing  the  teetli. 
With  forceps  having  beaks  that  are  not  serrated, 
teeth  having  conical  tapering  roots  will  prevent 
the  perfect  fitting  of  the  cutting  edge  ;  these  will 
sometimes  slip  through  the  posterior  opening  of 
the  upper  or  lower  alveolar  j)airs  with  great  force. 
The  writer  has  seen,  in  one  instance,  a  tooth  slip 
through  the  beaks  of  an  unserrated  pair  of  for- 
ceps and  break  a  pane  of  glass  in  front  of  the 
chair,  and  an  under  single  molar  root  which 
shot  up  with  sufficient  velocity  to  penetrate  the 
soft  palate. 

In  extracting,  particularly  under  nitrous 
oxid,  no  instrument  should  be  used  which  will 
not  securely  retain  any  tooth  or  root  until  it  is 
safely  placed  outside  the  mouth. 

Elevators  are  wholly  out  of  place  when  work- 
ing under  an  anesthetic.    They  permit  no  control 
of  the  root  or  tooth  whatever,  and  the  liability 
of  a  tooth  slipping  into  the  throat  under  such 
circumstances  is  too  great  to  warrant  the  risk. 
The  art  or  "  knack  "  of  extract- 
ing does  not  consist  of  giving  a 
rotary    motion    to    one    kind    of 
tooth  and  a  lateral  or  "  in-and-out 
motion  "  to  another,  but  rather  of 
"  working"  the  tooth  in  the  socket 
without   any    pulling    until    it    is 
started  or   loosened   from  its    at- 
tachment, when  the  pulling  force 
may  be  applied,  and  to  do  this  the 
forceps    must   be    placed    upon    a 
tooth  so  nicely  that  the  tooth  and 
Alveolar  forceps.  instrument  will  feel  to  the  hand 


636  EXTRACTION  OF  TEETH   UNDER  NITROUS  OX  ID. 

as  one  continuous  object,  so  tliat  the  slightest  motion  in  any  direction 
will  have  ininiediate  efh'ct  in  "  starting  "  the  tooth.  The  operation  is 
completed  hy  continued  working  while  the  pulling  is  applied  in  the 
direction   which  will  prove  the  most  effective  in  dislodgment. 

This  "  working"  should  be  done  with  as  little  motion  as  is  possible, 
for  the  smallest  degree  of  straining  upon  the  process  laterally  only 
adds  so  much  more  distention  to  the  alveolar  plates,  and  increases  the 
inflammation  and  pain  after  the  operation.  When  nitrous  oxid  was 
first  introduced  antl  extracting  was  transferred  to  those  who  made  it  a 
s[)ecialty,  it  was  noticed  that  there  was  less  soreness  of  the  mouth  follow- 
ing the  operation,  and  it  was  thought  by  some  that  the  oxygen  of  the 
gas  produced  a  beneficial  effect  upon  the  blood  which  caused  better 
healing,  but  such  is  not  the  case. 

The  object,  in  extracting,  of  one  who  becomes  expert  by  constant 
practice  is  to  save  the  surrounding  parts  from  all  unnecessary  strain, 
consequently  less  pain  and  soreness  follows  the  operation.  There  are 
teeth  having  curved  and  divergent  roots,  and  cases  of  exostosis,  which 
■will  require  great  effort  to  remove,  but  even  in  these  the  position  as- 
sumed and  the  process  of  "  w^orking "  the  tooth  in  the  direction  of 
the  force  applied  all  tend  to  accomplish  the  result  with  less  injury  than 
Avould  be  otherwise  produced. 

In  this  way  the  breaking  of  a  tooth  need  seldom  occur  unless  inten- 
tionally. If  in  extracting  an  upper  or  lower  molar  one  finds  by  the 
extra  amount  of  force  required  that  it  will  not  readily  yield,  then  it  is 
better  to  break  the  crown  off  and  with  the  sharp  alveolar  forceps  remove 
the  roots  separately.  This  can  be  done  with  less  injury  to  the  alveolar 
plates  than  if  much  greater  force  were  applied  to  remove  the  tooth 
as  a  whole. 

There  will  be  cases  of  fracture  of  points  of  roots  which  are  much 
curved  or  divergent,  but  many  of  these  retained  fragments  may  be  per- 
mitted to  remain  until  in  the  process  of  exfoliation  they  come  to  the 
surface  if  their  retention  is  regarded  as  likely  to  give  rise  to  less 
trouble  than  the  injury  incident  to  their  removal  would  cause.  But 
these  need  rarely  occur  if  the  operator  has  by  experience  acquired  that 
sense  of  feeling:  which  tells  him  at  once  the  direction  of  the  curve  or 
the  size  of  the  exostosis. 

Inverted  or  impacted  third  molars  are  the  most  difficult  cases  which 
present  themselves  for  extraction.  Instead  of  being  surrounded  by 
pliable  process  they  are  planted  in  compact  bone  at  the  angle  of  the 
jaw,  bound  in  by  the  second  molar  in  front  and  hard  bone  on  the 
buccal  side,  so  that  above  it  in  the  angle  is  the  only  direction  offered 
for  removal,  working  them  toward  the  tongue  where  the  bone  is 
thinnest. 


THE  OPERATION  OF  EXTRACTION.  637 

In  addition  to  the  difficulty  in  removing  these  teeth,  this  severe 
process  of  pressing  the  inner  alveolar  plate  toward  the  tongue  excites 
a  state  of  inflammation,  easily  communicated  to  the  soft  tissues  of  the 
throat,  and  the  after-eifects  assume  in  many  cases  such  serious  condi- 
tions that  it  is  better  practice  to  remove  the  second  molar. 

If  the  third  molar  is  sound  it  may  remain  and  will  cause  no  further 
trouble,  as  the  primary  difficulty  was  caused  by  crowding  and  pressing 
upon  the  second  molar ;  and  should  it  be  necessary,  from  decav,  to  re- 
move it,  the  extraction  of  the  second  molar  first,  renders  the  operation 
simple  and  easy  of  accomplishment. 


CHAPTER    XXI.    (Concluded). 

LOCAL  ANESTHETICS  AND    TOOTH    EXTRACTION. 

By  Henry  H.  Burchard,  M.  D.,  D.  D.  S. 


Prior  to  the  discovery  and  application  of  cocain,  the  local  anes- 
thetics employed  to  produce  a  condition  of  analgesia  of  the  structures 
surrounding  a  tooth  to  be  extracted  were  sprays  of  extremely  volatile 
substances.  Through  the  rapid  evaporation  of  a  spray  of  one  of  the 
lighter  hydrocarbons,  a  condition  of  refrigeration  of  tissues  was  brought 
al)out  during  which  a  tooth  could  be  extracted  painlessly.  Sprays  of 
rhigolene  and  of  ethylic  ether  have  been  superseded  by  those  of  ethyl 
and  of  methyl  chlorid,  these  substances  being  more  volatile  ;  directed 
in  a  tine  spray  over  the  gum  of  the  tooth  to  be  extracted,  an  intense 
local  anemia  is  produced,  and  as  a  consequence  analgesia  results.  If 
the  refrigeration  be  rapidly  produced  and  the  operation  be  performed 
promptly  upon  the  attaining  of  analgesia,  the  frozen  tissues  recover 
with  but  slight  reaction.  It  is  to  be  remembered  that  the  tissues  are 
frozen,  and  if  the  action  be  prolonged  a  condition  akin  to  chilblain  is 
present.  The  mode  of  application  is  as  follows:  All  of  the  mucous 
membrane,  except  that  over  the  roots  of  the  doomed  tooth,  is  to  be  pro- 
tected from  the  spray  by  means  of  napkins.  The  spray  is  directed 
against  the  exposed  gum,  the  vial  containing  the  ethyl  chlorid  being 
held  about  a  foot  from  the  mouth.  When  the  gum  becomes  intensely 
anemic,  indicated  by  pronounced  whiteness,  the  tooth  is  to  be  extracted. 
Ethyl  chlorid  must  be  kept  in  a  cool  place,  and  far  from  any  flame  ;  it 
is  inflammable  and  explosive. 

Preparations  containing  cocain  (benzoyl-methyl-ecgonin)  have  to 
a  great  extent  superseded  all  other  local  anesthetics  employed  for  this 
purpose.  It  was  clearly  shown  soon  after  the  introduction  of  this 
alkaloid  that  its  local  anesthetic  action  when  apjilied  to  the  gums  did 
not  extend  beyond  the  depth  of  the  mucous  membrane,  so  that  its  epi- 
dermic application  does  not  render  the  operation  of  tooth  extraction 
painless.  The  hypodermatic  application  was  found  to  render  the  tissues 
infiltrated  perfectly  analgesic.  A  recklessness  was  evinced  in  its  use 
after  this  method  which  was  promptly  followed  by  repeated  disasters ; 

639 


640  LOCAL  ANESTHETICS  AND  TOOTH  EXTRACTION. 

•A  formidable  list  of  casualties  ^rew.  ivepoi'ls  of  cases  of  respiratory 
and  of  cardiac  paralysis  foUowiiii;"  its  ein|)I<)yinent  were  not  uncommon. 
It  apparently  needed  disaster  to  demonstrate  that  cocain  helonj^cd  in  the 
category  of  actively  poisonous  alkaloids,  being  by  no  means  the  bland 
and  safe  agent  many  operators  seemed  to  think  it.  This  lesson,  learned 
at  great  cost,  is  one  the  operator  is  ever  to  heed,  particularly  in  the 
hypodermatic  employment  of  the  agent.  J)r.  JNI.  JI.  Cryer  has  re- 
ported^ cases  of  ascending  degeneration  of  the  trunks  of  the  maxillary 
nerves  following  upon  cocain  injections  about  the  jaws. 

For  the  origin,  composition,  physiological  effects,  and  toxicology  of 
the  drug  the  student  is  referred  to  the  standard  works  upon  materia 
niedica.  There  are  several  points,  however,  which  cannot  be  over- 
emphasized, the  first  being  in  regard  to  the  drug  itself.  A  full  dose  of 
cocain  hydrochlorid  by  the  stomach  is  about  gr.  f .  The  composition 
of  the  commercial  specimens  is  not  constant ;  some  of  them  appear  to 
contain  the  actively  poisonous  alkaloid  isatropylcocain.  A  safe  dose 
when  applied  hypodermatically  is  not  in  excess  of  gr.  \. 

The  lethal  effect  of  cocain  is  upon  the  res})iratory  centre.  Its 
absorption  is  followed  by  a  stimulation  of  the  cardiac  and  respira- 
tory functions,  which  is  commonly  followed  by  a  reaction,  the  stimu- 
lation giving  way  to  depression.  Idiosyncrasies  as  to  the  effects  of 
cocain  are  common  ;  cases  of  susceptible  women  have  been  noted  in 
which  gr.  \  produced  toxic  effects.  It  is  to  be  noted  that  the  depres- 
sion following  as  a  secondary  effect  upon  the  primary  stimulation  may 
not  occur  for  an  hour  or  later. 

In  prescribing  cocain  for  hypodermatic  injection,  the  analgesic  is 
the  first  element  to  be  considered  in  the  prescription.  The  dose  is  not 
to  exceed  gr.  l.  The  second  factor  demanding  attention  is  a  physio- 
logical antidote,  one  which  Avill  not  neutralize  the  analgesic  effect  and 
yet  will  prevent  the  toxic  action  of  the  cocain  upon  the  cardiac  and 
respiratory  functions.  Morphin  is  that  agent.  As  its  full  physiological 
effect  is  not  required,  a  small  dose,  gr.  ^,  will  be  sufficient.  The  next 
ingredient  of  the  prescription  is  an  agent  which  shall  prevent  abrupt 
spastic  contraction  of  the  arteries  and  heart.  Trinitrin  is  this  agent. 
One  drop  of  the   1   per  cent,  solution  is  the  indicated  dose. 

Fungi  develop  freely  in  solutions  of  cocain,  so  that  if  the  pre- 
scription is  to  be  a  permanent  solution,  an  antiseptic  is  required  to 
prevent  decomposition.  Cinnamic  alcohol  answers  well  for  this  pur- 
pose. One  drop  of  carbolic  acid  to  each  half-grain  of  cocain  is  an 
efficient  antiseptic.  By  boiling  cocain  is  split  up  into  methyl,  benzoic 
acid,  and  ecgonin,  so  that  cocain  solutions  cannot  be  sterilized  by 
boiling. 

'  Proc.  Academy  of  Stomatology,  Philadelphia,  1896. 


COCAIN.  641 

The  dose  commonly  employed  of  the  components  of  the  prescription 


IS- 


^. 

Cocainse  hydrochlorid., 

gr-i; 

Morphine  sulph., 

gr-  T2 ; 

or  Atropinse  sulph,, 

gr-  15  0  ; 

Trinitrin.  (1  per  cent,  sol.), 

gtt-j; 

Acid,  carbolic. 

gtt.j; 

Aquae, 

q.  s. 

3SS. — M. 

S.  The  above  represents  a  half-syringefiil  and  is  a  full  dose. 

This  solution  has  been  employed  with  general  success,  provided 
strict  antise})tic  precautions  have  been  taken.  Untoward  results  are 
occasionally  found  even  with  this  seemingly  safe  formula. 

In  the  hypodermatic  use  of  cocain  the  relatively  safe  maximum  dose 
should  never  be  exceeded  and  the  exact  amount  administered  in  a  given 
case  always  definitely  known.  A  common  error  has  been  the  dependence 
upon  solutions  of  a  given  percentage  composition.  The  danger  of  such 
dependence  becomes  evident  when  it  is  considered  that  the  safe  maxi- 
mum dose  of  cocain  salt  may  be  easily  exceeded  by  the  use  of  a  sufficient 
(piantity  of  a  low-percentage  solution,  while  on  the  other  hand  it  is 
quite  possible  to  keep  within  the  limits  of  safety  by  using  minute 
quantities  of  a  high-percentage  solution.  The  supposed  harmlessness 
of  a  dilute  cocain  solution  is  erroneous  and  misleadiup:  unless  the  factor 
of  the  absolute  quantity  of  the  drug  contained  in  a  given  amount  of 
solution  is  constantly  kept  in  mind. 

A  method  which  is  in  all  respects  safer  and  which  enables  the  oper- 
ator at  all  times  to  know  the  exact  amount  of  cocain  salt  injected  is  to 
make  the  solution  upon  the  basis  of  eight  grains  of  the  salt  to  one  ounce 
of  the  menstruum,  which  will  give  one  grain  in  each  drachm  and  -^-^  of 
a  grain  in  each  minim.  Of  such  a  solution  from  five  to  eight  minims 
may  be  injected  about  a  tooth  with  a  reasonable  degree  of  assurance 
that  the  safe  limits  of  physiological  eifect  have  not  been  exceeded. 

The  menstruum  in  which  these  ingredients  are  combined  is  an  inter- 
esting feature.  It  has  been  repeatedly  shown  that  the  injection  of  a 
quantity  of  water  will  ]n'oduce  anesthesia  of  a  region.  The  nerve  fila- 
ments are  compressed  by  the  fiuid  and  do  not  transmit  painful  impres- 
sions. 

Dr.  Schlcich  of  Greifswald '  follows,  for  the  induction  of  local  anes- 
thesia for  operations  in  general  surgery,  an  infiltration  method.  The 
injection  is  divided  and  the  punctures  made  seriatim  about  the  territory 
to  be  operated  upon.  The  remarkable  feature  of  his  procedure  is  the 
minute  dose  employed.     He  uses  a  1  :  4000  solution  of  cocain,  to  which 

1  T.  Parvin,  Proc.  Phila.  Co.  Med.  Soc,  Nov.  13,  1895. 
41 


642  LOCAL  ANESTHETICS  AND   TOOTH  EXTRACTION. 

is  added  i  of  1  per  cent,  sodium  chlorid  and  a  small  (jnantity  of"  4  per 
cent,  tricresol.  One  syrinoeful,  ahont  u  drachm,  is  suflicient  to  infil- 
trate the  tissues  about  a  tooth  and  render  its  extraction  ])ainless.  A 
drachm  of  the  1  :40()0  solution  contains  about  gr.  yL  of  cocain.  The 
stronijest  solution  employed  by  Schleich  is  a  1  :  500.  A  drachm  of  such 
a  solution  would  contain  less  than  gr.  \  of  cocain.  Dr.  W.  F.  Litch 
(ibid.)  has  pointed  out  that  low-percentage  solutions  will  give  a  safer 
result  than  those  of  high  percentage,  even  though  the  absolute  amount 
of  the  drug  should  be  the  same.  It  is  seen,  therefore,  that  the  quan- 
tity of  menstruum  in  which  the  dose  of  cocain  is  suspended  is  an  im- 
portant consideration. 

Tablets  for  making  Schleich's  solutions  may  be  had  of  pharmaceu- 
tists.    Tablets  for  making  the  strong  solution  contain — 

I^.  Cocainte  hydrochl.,  S^'-k) 

Morphinse  hydrochl.,  gr.  ^ ; 

Sodii  chlorid.,  gr.  ^. 
S.  Dissolve  in  TTL  100  of  distilled  water. 

Almost  without  exception  the  nostrums  advertised  and  sold  under 
high-sounding  titles,  for  employment  in  this  field,  contain  cocain. 
Neither  their  names  nor  any  information  vouchsafed  by  their  venders 
give  any  indication  of  the  amount  of  alkaloid  present,  and  so  all  of 
them  should  be  tabooed.  It  is  nothing  short  of  criminal  to  employ 
these  nostrums  without  a  knowledge  of  their  exact  composition. 

Tropacocain  (benzoyl  pseudo-tropin)  has  been  employed  to  render 
the  operation  of  tooth  extraction  painless.  It  possesses  decided  advan- 
tages over  cocain.  It  is  only  one-half  as  toxic  ;  has  but  slightly  de- 
pressant action  upon  the  cardiac  ganglia  ;  has  no  paralyzant  action  upon 
the  respiration ;  anesthesia  is  more  quickly  produced,  and  its  solutions 
are  slightly  antiseptic.  Solutions  of  the  drug  are  made  in  distilled 
water ;  the  full  dose  is  gr.  ^  to  f . 

The  reader,  of  course,  at  once  draws  the  correct  inference  that 
Schleich's  method  gives  promise  of  safety.  Applications  made  hypo- 
dermatically  of  the  elaborated  prescription  presented  are  not  without 
danger  even  in  physiological  dose. 

It  is  necessary  that  the  field  of  operation  be  made  aseptic  before 
injection.  The  mouth  should  be  washed  repeatedly  with  a  powerful 
antiseptic,  3  per  cent,  pyrozone,  10  per  cent,  electrozone,  or  3  per  cent, 
formaldehyd  solution. 

The  syringe  should  be  aseptic ;  repeated  washing  of  syringe  and 
points  in  a  25  per  cent,  solution  of  phenol  sodique  will  serve  this  end 
without  detriment  to  the  syringe  piston  or  the  metallic  parts  of  the 


SCHLEICH'S  SOLUTIONS.  643 

svriiige.  A  syringe  having  stout  finger-rests  and  holding  one  drachni 
is  employed.  The  needles  should  be  reinforced  for  half  their  length, 
and  should  have  sharp,  fine  points. 

The  gum  is  to  be  dried  and  touched  with  a  20  per  cent,  solution  of 
cocain  ;  in  five  minutes  the  needle  may  be  inserted  painlessly.  The 
syringe  is  filled  with  the  analgesic  solution,  the  needle  screwed  on,  and 
the  piston  pressed  down  until  all  air  is  expelled  from  the  syringe  and 
needle.  The  latter  is  now  thrust  into  the  gum  about  midway  between 
the  neck  of  the  tooth  and  the  apex  of  the  root,  until  it  comes  in  contact 
with  the  alveolar  process,  when  it  is  slightly  withdrawn  and  a  few 
drops  of  the  solution  are  driven  into  the  tissues.  A  second  injection  is 
made  over  the  apex  of  the  root ;  if  the  strong  solutions  be  used,  the 
amount  of  fluid  injected  must  not  contain  more  than  gr.  ^  of  cocain ; 
even  though  several  punctures  be  made.  Care  must  be  exercised  to 
confine  the  injection  to  the  tissues  of  the  gum  ;  if  the  submucous  tissue 
beneath  the  junction  of  the  cheek  and  gum  be  injected  into,  alarming 
emphysema  may  result. 

For  multirooted  teeth  an  injection  is  made  over  each  root.  If 
Schleich's  solution  be  employed,  a  full  drachm  of  fluid  should  be  in- 
jected, until  the  gum  over  the  tooth  is  tense  and  white,  when  extrac- 
tion may  be  accomplished  painlessly. 

In  some  instances  the  intense  anemia  present  at  the  moment  of 
extraction  may  be  succeeded  by  local  hemorrhage  as  soon  as  reaction 
is  established.  An  antiseptic  hemostatic  should  be  applied  to  the 
alveolus  after  extraction  ;  phenol  sodique,  full  strength,  is  an  admirable 
agent  for  this   purpose. 

The  imminent  dangers  to  be  feared  in  this  connection  are  :  first,  the 
toxic  effects  of  the  drug.  As  these  are  usually  manifested  in  contrac- 
tion of  the  bloodvessels  the  antidote  is  amyl  nitrite.  A  supply  of  pearls 
each  containing  TTliij  of  amyl  nitrite  should  be  kept  in  the  medicine 
cabinet.  When  a  patient  exhibits  great  pallor,  a  small  pulse,  and  bluish- 
white  lips,  one  of  these  pearls  is  crushed  in  a  napkin  and  the  nitrite 
quickly  inhaled.  The  conjoint  administration  of  gtt.  xx.  aromatic 
spirits  of  ammonia,  or  about  half  an  ounce  of  brandy,  is  advised. 
Should  these  measures  not  jirove  pntmptly  eflPective,  artificial  respirati(m 
should  be  immediately  begun  and  be  ])rosecuted  vigorously. 

The  second  danger  is  septic  infection,  either  through  imperfectly 
sterilized  instruments  or  by  carrying  se]itic  organisms  from  the  mucous 
membrane  covering  the  gum  into  the  deeper  tissues  during  the  opera- 
tion of  injection.  This  is  avoided  by  a  careful  sterilization  of  the 
syringe  before  it  is  used,  and  the  rejieated  applications  of  antiseptic 
mouth-washes  previous  to  injection.  Prescriptions  Avhich  contain  a 
large  percentage  of  carbolic  acid  are  liable  to  cause  sloughing. 


644  LOCAL  ANESTHETICS  AND   TOOTH  EXTRACTION. 

Inicclioiis  forced  Ix^twccii  the  periosteum  and  boiiu  niuv  produce 
serious  injury. 

The  iutroduetion  of  eucain  as  u  loeul  auesthetie  was  due  to  the 
observed  eheniieal  siniiUirity  of  that  synthetic  body  with  cocaiu  ;  an 
instance  of  presaging  the  physiological  effects  of  a  drug  by  its  chemical 
composition.  Its  local  effect  upon  blooilvessels  is  to  produce  hyper- 
emia, instead  of  the  ischemia  induced  by  cocaiu.  It  is  less  poisonous  than 
cocain  and  its  solutions  are  chemically  more  stable.  Its  primary  action 
u])on  the  central  nervous-  system  is  one  of  exaltation,  and  this  is  followed 
by  paralysis,  the  effect  being  central,  not  ascending.  The  sedative 
central  iuHucuce  causes  a  quickening  of  the  heart-beats  through  sedation 
of  the  inhibitory  (pneumogastric)  nerves.  Although  eucain  is  less  toxic 
than  cocain  it  also  produces  a  greater  degree  of  analgesia ;  so  that  the 
dose  need  not  be  greater  than  that  of  cocain,  about  ^  to  f  of  a  grain 
being  the  maximum. 

Eucain  may  be  kept  in  permanent  and  stable  solution  in  distilled 
water.  A  10  per  cent,  solution  may  be  made  in  distilled  w^ater  (48 
grains  of  eucain  hydrochlorid  to  the  ounce  of  distilled  water)  and  the 
solution  sterilized  by  boiling,  which  does  not  decompose  eucain.  From 
five  to  eight  minims  of  such  a  solution  is  a  proper  dose.  The  precau- 
tions to  be  observed  and  the  mode  of  application  are  the  same  as  for 
cocain. 

Besides  the  dangers  arising  from  the  hypodermatic  administration 
of  a  physiological  overdose  of  this  class  of  analgesic  drugs,  and  the  local 
danger  of  infection  from  non-sterile  solutions  or  instruments,  there  is  to 
be  strongly  emphasized  the  danger  of  local  necrosis  due  to  the  poisonous 
effect  of  the  drugs  themselves  upon  the  tissue  elements  when  directly 
injected.  In  nearly  all  cases  in  which  extraction  is  sought  the  tissues 
about  the  tooth  are  in  a  condition  of  lowered  vitality,  brought  about  by 
the  local  toxemia  resulting  from  the  infection  which  has  produced  the 
inflammatory  process.  The  injection  of  a  proto])lasmic  poison,  such  as 
cocain,  eucain,  and  their  congeners,  into  the  inflamed  territory  causes  a 
still  further  depression  of  vital  resistance,  which,  if  sufficiently  })ro- 
nounced,  may  become  total  and  permanent.  Hence,  tissue-death  or 
necrosis,  with  subsequent  sloughing,  will  necessarily  result. 

AVhere  the  inflammatory  process  about  a  tooth  is  at  all  pronounced, 
it  is  much  Aviser  to  discard  local  anesthetic  methods  for  the  far  safer 
procedure  of  general  anesthesia  induced  by  nitrous  oxid  or  ether. 


CHAPTER    XXII. 
PLANTATION  OF  TEETH. 
By  Louis  Ottofy,  D.  D.  S. 


The  teansplaxtatiox  of  a  tooth  signifies  the  insertion  of  a  nat- 
ural tooth  into  a  natural  alveolus  other  than  the  one  it  originally  occu- 
pied. The  tooth  may  be  an  old  and  dry  specimen  transplanted  into  an 
alveolus  from  which  a  tooth  has  been  recently  removed,  or  it  may  be  a 
freshly  extracted  tooth  transplanted  from  one  part  of  the  mouth  of  an 
individual  to  another  part  of  the  mouth  of  the  same  individual,  or  it 
may  be  a  freshly  extracted  tooth  transplanted  from  the  mouth  of  one 
person  into  that  of  another. 

Replaxtatiox  signifies  the  replacing  of  a  tootli  in  the  alveolus 
whence  it  had  been  removed  by  design  or  accident.  The  operation  may 
be  performed  at  once  or  at  any  time  before  the  socket  is  filled  with  new 
tissue. 

Under  the  term  implantation  are  included  all  those  operations 
which  involve  the  formation  of  an  artificial  alveolus  for  the  reception 
of  the  root  of  a  human  tooth.  The  operation  of  altering  the  size  or 
form  of  an  existing  alveolus  to  receive  a  tooth  belongs  to  this  class, 
although  it  is  a  combination  of  trans-  and  implantation. 

The  operation  of  rephintation  probably  far  antedated  that  of  trans- 
plantation, as  the  latter  preceded  implantation,  but  its  definite  history 
is  unknown.  It  is  safe  to  presume  that  it  has  been  practiced  ever  since 
mankind  conceived  of  the  natural  healing  power  of  the  body.  Even 
when  performed  with  crudity  and  without  any  clear  comprehension 
of  the  mode  of  repair,  favorable  results  have  been  reported.  The  ope- 
ration is  at  present  an  uncommon  one  :  the  condition  for  the  relief  of 
which  it  was  at  one  time  practiced  with  comparative  frequency,  chronic 
alveolar  abscess,  has  been  found  amenable  to  less  radical  treatment. 

The  operatioii  of  transplantation  is  first  noted  in  the  writings  of 
Ambroise  Pare  in  the  sixteentli  century,  though  credit  has  generally 
been  given  to  Dr.  John  Hunter,  wlio  gave  the  subject  considerable 
attention.  Hunter's  experiment  of  im[)hinting  a  tooth  in  the  comb  of 
a  cock  is  classical.     The  records  of  the  operation  do  not  exhibit  any 

645 


640 


PLANTATION  OF  TEETH. 


great  measure  of  success  attendinu^  it.  Hunter  noted  cases  of  trans- 
plantation of  dead  teeth  -wliieli  remained  for  years. 

No  one  disputes  with  Dr.  Younger  of  San  Francisco  the  authorship 
of  the  operation  of  implantation.  The  date  of  his  first  operation  was 
June  15,  1885,  although  Bourdet  in  1780  was  the  first  to  mention  the 
operation,  stating  that  "  irresponsible  persons  chiim  to  make  a  socket, 
and  ini])lant  into  it  a  tooth."  An  attempt  at  partial  implantation  is 
recorded   in   Dental  Cosvios,  vol.  xix.  p.  258. 

In  order  that  an  intelligent  conception  may  be  had  of  the  intimate 
nature  of  the  biological  conditions  which  surround  the  teeth  after  inser- 
tion by  either  of  these  operations,  it  is  essential  to  study  the  general 


Fig.  573.1 


Fig.  57-i. 


15       1 

A  tooth  and  its  normal  attachment  and  vascular 
supply :  1,  1,  Apical  pericementum  in  which 
is  seen  the  main  pericemental  artery,  5 ;  2,2, 
anastomosing  bloodvessels  or  channels  of 
the  alveolar  walls ;  3,  3,  the  marginal  anasto- 
mosis of  alveolar  and  pericemental  arteries. 


Conditions  following  replantation:  1,  1',  The 
pericementum  and  inflammatory  efl'usion 
between  pericementum  and  alveolar 
walls :  2,  2,  source  of  blood-supply  to  the 
area  of  repair;  3,  3,  terminations  of  alveo- 
lar arteries ;  5,  obliterated  apical  artery. 


processes  which  attend  the  repair  of  tissues,  and  their  behavior  toward 
foreign  bodies. 

As  all  of  these  operations  are"  performed  under  the  strictest  antiseptic 
precautions,  the  consideration  of  bacterial  influence  is  omitted  at  this 
juncture.  As  it  is  impossible  to  secure  specimens  which  would  show 
these  several  parts  in  their  true  relations,  the  illustrations  are  neces- 
sarily diagrammatic  and  theoretical. 

'  Figs.  573-576  are  from  drawing.s  by  Dr.  H.  H.  Burchard. 


BIOLOGICAL   CONDITIONS  IN  PLANTATION. 


647 


Fitr.  o73  exhibits  a  longitudinal  section  of  an  inrisor,  its  attachments 
and  support,  together  with  its  vascular  supply,  in  its  normal  relations, 
the  bloodvessels  from  the  pericementum  anastomosing  with  those  of 
the  alveolar  periosteum.  The  pericemental  space  is  filled  with  fibrous 
tissue.     To  avoid  confusion  the  nerves  and  veins  have  been  omitted. 

Fig.  574  represents  the  conditions  following  replantation.  The  tooth 
has  been  sterilized  and  its  pulp  canal  hermetically  sealed.  The  perice- 
mental bloodvessels  have  been  destroyed  in  extraction.  Portions  of 
the  pericementum  are  seen  clinging  as  fibrous  remnants  to  the  cemen- 
tum.    The  remainder  of  the  alveolus  is  filled  with  infiammatory  corpus- 


FiG.  575. 


Fig.  576. 


Conditions  following  transplantation  :  1,  1', 
Embryonic  tissue  which  will  be  organ- 
ized into  repair  tissue  replacing  the 
original  pericementum ;  5,  obliterated 
apical  vessels. 


Conditions  following  implantation :  1, 1,  Alveo- 
lar arteries  ;  2,  2,  gingival  margin  :  3,  inflam- 
matory still  unorganized  tissue  filling  the 
space  between  the  cementum  and  walls  of 
the  artificial  alveolus;  4,  4,  phagocytes,  mul- 
tinucleated cells  attacking  cementum  of  im- 
planted tooth ;  .5,  obliterated  apical  vessels. 


cles.  The  vascular  supply  to  the  regenerated  pseuclo-pericementum  is 
derived  first  from  the  vessels  of  the  alveolar  2)eriosteum  via  the  alveolar 
process. 

Fig.  575  shows  the  conditions  existing  soon  after  the  operation  of 
transplantation.  The  mechanical  violence  of  extraction  has  irregularly 
enlarged  the  natural  alveolus.  The  tooth,  its  a[iex  rounded,  is  shown 
Avith  the  blunted  extremity.  The  vascular  suj)j)ly  is  similar  to  that 
of  Fig.  574.     The  alveolar  space  is  filled  wdth  infiammatory  corpuscles. 


648  PLANTATION  OF  TEETH. 

Fig.  57G  exhibits  the  conditions  probably  existent  soon  after  an  im- 
plantation operation.  The  vascular  supply  is  the  same  as  shown  in  Figs. 
574  and  575.  Instead  of  having  a  layer  of  periosteal  bone,  the  for- 
mation of  the  artificial  alveolus  is  into  the  spongy  medullary  bone. 
The  artificial  alveolus,  being  necessarily  dilferent  in  size  and  outline 
from  the  tooth,  is  tilled  with  inflammatory  producfts.  Some  of  the  cells, 
becoming  multi-nucleated,  are  seen  to  be  exercising  their  phagocytic — 
or,  in  this  connection,  resorptive — function  u])(»n  the  cemeutum. 

Replantation  and  Transplantation. 

Replantation. — In  the  present  state  of  (huital  practice  the  following 
conditions  may  be  regarded  as  warranting  replantation  : 

(1)  When  a  tooth  has  been  dislodged  by  traumatism,  a  blow  by  a 
ball,  club,  or  fall,  etc. 

(2)  When  a  tooth  has  been  accidentally  removed  by  the  slipping  of 
the  forceps  during  the  performance  of  a  dental  extraction, 

(3)  When  some  disease,  otherwise  incurable,  aifects  either  the  root  or 
some  portion  of  its  alveolus. 

The  first  two  causes  are  practically  the  most  frequent  under  which 
replantation  is  justifiable. 

In  case  a  tooth  has  thus  been  dislodged  and  found,  it  should  at  once 
be  cleansed  of  all  foreign  matter  and  then  be  carefully  examined  for 
fractures  or  other  injury.  Any  cavities  present  should  be  filled,  the 
contents  of  the  root  canal  removed,  and  the  space  filled  in  the  manner 
described  later  ;  fractured  or  abraded  portions  or  surfaces  are  to  be  made 
smooth,  and  the  tooth  placed  in  an  antiseptic  solution.  A  careful  ex- 
amination of  the  socket  should  then  be  made.  It  will  be  noticed  when 
the  accident  has  befallen  a  young  individual,  that  as  a  result  of  the 
flexibility  of  the  bone,  the  alveolar  process  is  seldom  fractured — an 
accident  more  prone  to  hajipen  in  adult  life. 

Some  discrimination  should  be  exercised  as  to  the  promptness  with 
which  to  replant  the  tooth.  If  there  is  considerable  inflammation  as 
the  result  of  injury,  it  is  not  advisable  to  immediately  re})lace  the  tooth. 
In  that  event  the  socket  should  be  made  aseptic  and  if  possible  normal 
hemorrhage  re-established.  As  a  general  rule  several  days  should  be 
allowed  to  intervene  when  the  inflammation  is  excessive  ;  otherwise  a 
tooth  may  be  replaced  at  any  time  as  soon  as  it  has  been  prepared. 

The  governing  pathological  ]H"inciple  is  as  follows  :  Immediately  after 
an  injury,  a  certain  amount  of  inflammation  takes  place  and  there  is 
retrograde  metamorphosis — a  destruction  or  breaking  down  of  tissue  ; 
and  this  is  not  the  most  favorable  time  to  expect  re-attachment  to  take 
place.     As  a  rule,  wdthin  a  few  days  a  building-up  process,  constructive 


REPLANTATION  AND   TEANSPLANTATJON.  649- 

metamorphosis,  has  set  in,  and  the  replacement  of  a  tooth  at  this  time  i& 
likely  to  be  followed  hy  more  favorable  results.  This  period  sets  in  at  any 
time  from  three  days  to  a  week,  the  socket  being  then  partially  tilled 
with  active  living  cells.  Just  prior  to  the  replacement  of  the  tooth  the 
socket  and  the  gum  surrounding  it  having  been  cleansed  and  sterilized, 
the  tooth  itself  being  brought  forth  from  its  antiseptic  medium,  it  must 
be  promptly  replanted.  As  a  rule,  constant  but  not  severe  pressure  will 
permit  the  tooth  to  assume  its  original  position  in  the  socket,  although 
sometimes  it  is  necessary  to  remove  a  part  of  the  apex  of  the  root  or 
slightly  deepen  the  socket  by  means  of  a  suitably  shaped  bur.  It  hap- 
pens occasionally  that  the  location  of  the  tooth  and  the  general  surround- 
ings are  such  that  a  tooth  like  this  may  be  retained  without  any  further 
attachment,  but  as  a  rule  it  is  not  safe  to  trust  to  uncertainties  regarding 
the  attachment  of  the  tooth.  An  impression  of  the  tooth  and  its  neigh- 
bors can  be  quickly  secured  with  ^Nlelotte's  compound  or  in  clay,  a  die 
is  easily  made,  from  which  a  cap,  such  as  will  be  described,  is  quickly 
made. 

It  is  needless  to  dwell  upon  the  second  cause  mentioned.  Xo  dentist 
can  ever  be  excused  for  accidentally  removing  a  sound  tooth,  but  in 
case  the  accident  does  happen  the  above  procedure  is  indicated. 

The  opportunities  enumerated  under  the  third  section  are  also,  for- 
tunately, exceedingly  rare.  The  cases  in  which  formerly  replantation 
was  resorted  to,  on  the  ground  that  the  case  was  incurable,  are  now" 
much  less  frequently  met  with,  and  w^hen  they  are  encountered  they 
often  yield  to  treatment,  which  is  now  more  clearly  understood — such 
as  amputation  of  the  root,  removal  of  the  necrosed  portion  of  the 
alveolar  process,  etc.  AVhen,  ho\\ever,  it  has  been  decided  to  extract 
a  diseased  tooth  and  to  replant  it,  diseased  portions  of  the  root  should 
be  removed  and  a  sufficient  time  allowed  to  elapse  before  replantation 
f(tr  the  socket  and  tissues  to  have  assumed  a  healthy  aspect,  even  if 
this  should  necessitate  the  enlargement  of  the  socket. 

In  cases  of  pyorrhea  alveolaris,  which  sometimes  has  been  suggested 
as  coming  under  this  class,  treatment  by  replantation  is  out  of  the  ques- 
tion, provided  the  case  has  made  sufficient  progress  to  suggest  such 
a  course.  Replantation  implies  the  presence  of  a  socket,  and  when 
pyorrhea  alveolaris  has  made  any  great  degree  of  progress,  the  socket 
is  wanting.  Hence  it  is  l)ut  in  rare  cases  that  an  attempt  to  cure  by 
this  method   is  justifiable. 

Dr.  Louis  Jack  '   has  recorded  marked  success  in  several  cases  at- 
tending an  operation  of  modified  replantation  for  the  cure  of  some  of 
the  earlier  phenomena  of  phagedenic  pericementitis,  notably  the  common 
malposition  due  to  what  has  been  termed  voluntary  tooth  movement. 
^  See  Trails.  Academy  of  StDinafolor/y,  1895. 


650  PLANTATION  OF  TEETH. 

Transplantation. — Tliere  is  a  hroadcr  range  for  the  ])ractice  of 
transplantation  tlian  either  of  the  other  operations  treated  in  tliis 
ehapter.  As  has  been  seen,  re])lantation  is  limited  in  its  a})})lieation, 
and  implantation  must,  from  the  nature  of  the  operation,  be  also  con- 
fined to  a  comparatively  circumscribed  sphere. 

The  operation  may  be  performed  at  any  period  of  an  individual's 
life,  although  as  a  ride  young,  vigorous,  and  mature  adult  life  offers  the 
greatest  promise  of  success.  Any  socket  in  any  part  of  the  mouth, 
when  placed  in  a  healthy  condition,  is  a  more  or  less  favorable  location 
for  the  reception  of  a  tooth  about  to  be  transplanted.  It  is  true  that 
sometimes  a  socket  needs  to  be  enlarged  or  deepened  for  this  purpose, 
but  this  is  a  comparatively  simple  matter.  Before  the  advent  of  the 
intelligent  practice  of  crown  and  bridge  work,  treatment  of  diseases 
of  the  })ulp  and  jx'ridental  membrane,  the  bleaching  of  teeth,  and  the 
intelligent  practice  of  orthodontia,  transplantation  was  resorted  to  as  a 
remedy  for  the  correction  of  many  trivial  disorders.  In  the  light  of 
the  present  day,  transplantation  is  confined  to  sockets  whence  teeth 
have  been  removed  for  any  cause  which  could  not  be  remedied  by  some 
other  method  of  treatment :  sockets  which  remain  as  the  result  of  the 
loss  of  teeth  from  accident  of  any  kind  (the  lost  teeth  not  having  been 
recovered) ;  from  which  roots  beyond  salvation  have  been  extracted ; 
from  which  diseased  teeth  must  be  removed  ;  from  which  roots  have 
been  removed  having  carried  crowns  or  having  served  as  abutments  for 
bridges  until  their  period  of  usefulness  has  passed. 

The  same  rule  laid  down  for  the  care  of  a  socket  previous  to  re- 
plantation holds  good  for  transplantation  ;  namely,  that  inflammation 
must  be  reduced,  and  the  tooth  transplanted  into  the  socket  at  a  time 
when  progressive  constructive  metamorphosis  is  taking  place.  This 
period  is  stated  as  usually  from  three  to  seven  days  after  the  removal 
of  the  tooth.  In  instances  where  considerable  disease,  such  as  a  chronic 
alveolar  abscess  of  years'  standing  has  been  present,  even  a  longer  time 
.should  be  allowed  to  intervene  before  transplantation. 

Preparation  of  Teeth  for  Plantation. 

With  the  exception  of  such  special  directions  as  are  necessary  in 
each  class  of  the  operations  described  in  this  chapter,  the  following 
general  directions  are  applicable  to  all  cases. 

The  Scion  Tooth. — For  replantation  a  recently  dislodged  tooth  is 
supposed  to  be  at  hand,  hence  there  is  a  fresh  tooth.  For  transplanta- 
tion it  is  implied  that  the  tooth  is  either  at  hand  or  about  to  be  secured, 
but  in  a  case  of  trans])lantation  or  implantation  the  age  of  the  tooth 
mav  be  unknown  and  indefinite.  Teeth  have  been  planted  whose  age 
and  origin  have  been  absolutelv  unknown,  and  they  have  become  firm 


PREPARATION  OF  TEETH  FOR  PLANTATION.  651 

in  their  new  locutions.  Xevertheless  it  seems  reasonable  to  take  the 
ground  that  whenever  it  is  possible,  teeth  should  be  fresh  and  something 
of  their  previous  environment  should  be  known.  There  are  no  cases 
on  record  where  disease  has  been  transmitted  through  the  medium  of  a 
planted  tooth,  although  portions  of  the  early  literature  of  this  subject  do 
indicate  such  results.  The  principal  objection  to  old  and  dry  teeth  is 
that,  the  water  having  been  evaporated,  these  teeth  are  almost  invaria- 
blv  fractured  or  cracked  from  shrinkage.  When  these  fractures  extend 
to  the  crown  portion,  the  enamel  frequently  chips  off  within  a  short 
time  after  the  tooth  has  been  planted  ;  while  in  some  instances  the 
■entire  root  has  been  fractured.  Another  objection  to  teeth  promiscu- 
ously gathered  is  that  it  is  seldom  possible  to  find  teeth  in  which  the 
crowns  are  sufficiently  perfect  to  be  serviceable  and  to  be  presentable 
in  the  mouth.  The  crown  of  a  dry  tooth  permits  of  but  slight  altera- 
tion with  the  grinding  stone  or  sandpaper  disk  without  endangering  its 
integrity  ;  w4iile  if  it  is  affected  by  caries  to  such  an  extent  as  to  require 
an  extensive  operation,  the  life  of  the  filling  is  likely  to  be  of  shorter 
duration  than  a  similar  operation  performed  on  a  freshly  extracted  tooth 
or  a  tooth  with  living  connections.  For  this  reason  it  is  preferable  to 
use  only  the  roots  of  teeth,  attaching  to  them  artificial  crowns.  This 
permits  the  selection  of  a  crown  suitable  in  size,  color,  and  shape,  and 
which  may  be  ground  for  articulating  purposes — an  important  matter 
in  these  cases. 

If  therefore  an  old,  dry  tooth  must  be  used,  let  it  be  carefully 
selected  with  regard  to  the  absence  of  checks  or  cracks  or  fractures, 
and  if  it  be  impossible  to  secure  a  tooth  with  such  a  crown,  let  there  be 
selected  a  good  root  to  w'hich  a  crown,  as  described  later,  can  be 
attached. 

If  a  freshly  extracted  tooth  can  be  secured,  even  though  the  crown 
may  be  sliglitly  carious,  the  necessary  filling  operation  is  advisable,  and 
such  a  tooth  should  be  used,  if  possible. 

Root-filling. — Roots  may  be  filled  either  from  the  apex  or  through 
an  opening  or  cavity  in  the  crown.  Gutta-percha  seems  to  answer  all 
the  necessary  purposes,  but  for  a  short  distance  from  the  apical  extrem- 
ity it  is  well  to  fill  with  gold  wire  or  ff)il. 

Pericementum, — The  theory  that  the  pericementum  becomes  revivi- 
fied does  not  seem  to  be  tenable;  at  least  the  proposition  that  life  is 
maintained  in  the  pericementum  fi)r  any  considerable  period  of  time 
after  the  tooth  has  been  removed  from  vital  attachment  is  not  in  accord 
with  general  physiological  laws,  although  periosteum  as  a  tissue  main- 
tains its  vitality  for  a  time  after  separation.^  For  the  pur])ose  of  secur- 
ing an  attachment  there  is  no  necessity  for  the  presence  of  the  perice- 

'  See  Ziegler's  General  Pathology. 


652 


PLANTATION  OF  TEETH. 


niciituin  ;  hut  it  is  ronsonnblc  to  assuino  tluii  the  nottror  to  luitural  states 
the  root  and  the  socket  are  in,  tlie  more  favorable  will  he  the  ])n)<rnosis. 
It  is  therefore  a  safe  rule  to  follow,  to  preserve  as  much  of  the  perice- 
mentum as  is  possible.  The  preservation  of  the  pericementum  has  an 
advantage  from  the  fact  that  after  the  tooth  has  been  planted,  the  peri- 
cementum under  the  influences  of  bodily  heat  and  moisture  expands 
and  thus  acts  in  the  nature  of  a  sponge  graft,  enabling  the  tissues  to 
more  quickly  obliterate  spaces  which  are  present  and  to  attach  them- 
selves to   the  root. 

Subsequent  Care  of  Planted  Teeth. — Numerous  methods  for  the 
retention  of  planted  teeth  have  been  recommended  by  \ari(»us  authors 
at  different  times.  While  many  of  them  are  original  and  ingenious,  all 
are  to  be  condemned  except  those  means  which  look  to  the  firm,  rigid^ 
immovable  retention  of  the  planted  tooth  for  a  definite  period,  that  of 
surgical  repair.  Neither  the  rubber-dam  splint,  silk  ligature,  nor  gold 
or  other  metal  wire  comes  vmder  this  heading.  Planted  teeth  must  be 
retained  immovably  for  a  period  of  two  to  six  weeks,  occasionally  from 
two  to  eight,  ten,  or  twelve  weeks.  The  shortest  time  of  immobility 
consistent  with  subsequent  attachment  is  preferable.  The  tooth  to  be 
transplanted  or  implanted  should  be  fitted  after  preparation  in  a  model, 
made  from  an  impression  of  the  gum  where  the  tooth  is  to  be  planted 
and  of  the  adjoining  teeth,  as  shown  in  Fig.  577. 

An  impression  is  then  taken  of  it  and  of  the  adjoining  teeth  on  each 
side.  A  retention  cap  is  then  savaged  to  cover  the  grinding  surfaces 
of  three  or  more  teeth,  half  the  length  of  the  crown  on  the  labial  surface 
and  nearly  the  full  length  on  the  lingual  or  palatal  surface,  as  shown 
in  Fig.  578. 


Fig.  578. 


Model  showing  pix-paied  toolh  in  place: 
a,  Gold  filling  at  cervical  joint. 


Model  !<lK<\viiig  rftcntiuu  cup 
in  situ. 


The  cap  may  be  made  of  pure  gold,  platinum,  or  German  silver. 
The  gauge,  according  to  the  metal  used,  should  be  from  No.  32  to 
No.  38.  This  cap  is  cemented  upon  the  cro^vns  adjoining  the  planted 
tooth  in  such  a  manner  that  it  may  be  removed  without  disturbing  the 


PREPARATION  OF  TEETH  FOR  PLANTATION.  653 

planted  tooth.  The  operator  can  remove  the  cap  by  springing  the 
metal  away  from  the  teeth,  examine  the  condition  of  attachment  of  the 
planted  tooth,  and  replace  the  cap  if  it  should  be  necessary.  Where 
the  articulation  interferes  with  the  retention  of  the  cap,  the  latter  may 
be  ligatetl  to  the  adjoining  teeth  in  addition  to  being  cemented  to  them, 
■and  still  admit  of  removal  without  disturbing  the  planted  tooth.  There 
js'at  present  no  method  of  ligaturing  or  banding  the  teeth  which  will 
permit  removal  of  the  ligature  or  band  without  more  or  less  disturbance 
•of  the  planted  tooth. 

Aside  from  the  necessity  of  immobility  for  a  certain  period,  the 
planted  tooth  and  surrounding  tissue  generally  require  but  little  atten- 
tion. In  occasional  cases  the  tissues  may  be  stimulated,  by  painting 
the  gum  with  a  mixture  of  equal  parts  of  tincture  of  aconite  root, 
chloroform,  and  iodin  paint  (the  latter  is  a  saturated  solution  of  iodin 
in  alcohol),  or  by  the  use  of  stimulating  mt)uth-washes,  notably  those 
containing  capsicum.  The  patient  should  be  cautioned  to  encourage 
the  downward  growth  of  the  gum  by  the  use  of  the  toothbrush,  to 
prevent  the  accumulation  of  remnants  of  food  or  saliva,  and  to  pre- 
vent their  subsequent  putrefaction  should  particles  become  unavoidably 
lodged  around  the  tooth  or  cap.  This  is  best  accomplished  by  using  a 
camel's-hair  brush  dipped  in  hydrogen  dioxid  or  pyrozone,  electrozone, 
meditrina,  etc.,  washing  out  the  interstices  frequently.  A  syringe  or 
spray  from  an  atomizer  may  be  used. 

Artificial  Roots. — Experiments  have  been  performed  looking 
toward  the  use  of  roots  other  than  those  of  natural  teeth.  Roots  made 
of  ivory,  corrugated  or  perforated  porcelain,  lead,  gold,  platinum,  and 
other  metals  have  been  used.  The  writer's  experiments  in  this  direc- 
tion have  all  resulted  in  failure.  There  is  no  recorded  evidence  that 
any  have  residted  successfully. 

Mode  of  Attachment. — As  to  the  mode  of  attachment  of  planted 
teeth  the  subject  is  clouded  in  obscurity.  From  the  nature  of  the  con- 
ditions it  is  difficult  to  secure  definite  information.  Dr.  Younger  holds 
to  the  belief  that  the  pericementum  becomes  revivified  and  hence  the 
attachment  is  almost  physiological.  Others  maintain  that  the  filling 
of  the  space  around  the  root  of  the  tooth  wdth  compact  bone  tissue 
is  sufficient  to  account  for  the  retention  of  the  tooth.  In  the  appear- 
ance of  planted  teeth  which  have  failed  there  should  be  found  the  best 
illustrations  of  the  causes  of  success.  It  is  ])robable  that  a  planted 
tooth,  by  reason  of  the  absence  of  the  cushion  fi)rmed  by  the  living 
pericementum,  causes  more  or  less  irritation  in  the  socket;  that  this 
irritation  leads  to  resorption  of  the  root ;  that  in  this  resorption  and 
the  subsequent  filling  up  of  these  resorbed  surfaces  are  found  reasons 
for  the  success  of  the  operation.      Fig.  579,  at  a,  a,  shows  how  a  par- 


654  PLANTATION  OF  TEETH. 

tially  rcs()rh(>(l  root   may  be    retained    in   place.     Thv   ]en<rtli  of  time 
(liirino-  Avhich  a  planted   tooth   is  retained  depends  entirely  upon   the 
rapidity  of  the  resorptive  process  and  the  activ- 
FiG.  579.  ity  of  the  tissues  in  maintaining  a  healthy  con- 

dition, lieplanted  and  transplanted  teeth  have 
been  known  to  do  good  service  for  from  twenty 
to  forty  years.  The  time  of  the  observation  as 
to  implanted  teeth  is  shorter,  the  oldest  cases 
being  less  than  twelve  years  old.  In  the  writer's 
observations,  extending  over  a  period  of  nearly 
ten  years,  a  number  of  teeth  have  been  noted 
An  implanted  tooth  in  ^vhich  havc  been  retained  successfully  for  that 
sto ; «, a, oxcavations of     period;  how  miich  longer  they  will  remain  ser- 

the  cemontum  due  to  re-         .        ,  ,  i         i      ,  ,  o  '^^ 

sorptive  process.  viccablc,    and   what   percentage   or    success   will 

attend  later  cases,  will  require  further  time  to 
determine.  Dr.  Younger  has  had  successfully  implanted  teeth  under 
observation  for  eleven  years. 

Precautions. — There  is  no  special  danger  connected  with  any  of  the 
operations  described  in  this  chapter,  provided  the  usual  antiseptic  pre- 
cautions are  observed  and  daup-erous  anesthetics  avoided.  Aside  from 
these,  during  the  operation  of  replantation  and  transplantation  no 
special  skill  is  necessary  ;  certain  precautions  are,  however,  essential. 
Inasmuch  as  implantation  is  an  essentially  esthetic  operation,  it  should 
be  borne  in  mind  that  it  is  confined  princijaally  to  the  ten  anterior  teeth, 
and  that  it  is  more  frequently  performed  in  the  upper  jaw  than  in  the 
lower.  The  territory  involved  is  therefore  limited.  The  operator  who 
contemplates  forming  in  this  territory  a  socket  for  the  reception  of  the 
root  of  a  tooth  should  be  intimately  acquainted  with  the  anatomical 
and  histological  relationships  of  the  various  parts. 

In  the  first  place  it  should  be  remembered  that  where  alveolar 
resorption  has  taken  place,  the  relative  depth  of  bone  is  considerably 
less  than  where  a  tooth  is  still  in  situ  and  surrounded  by  the  abnormal 
alveolar  process.  The  operator  must  therefore  not  penetrate  deeper 
into  the  bone  than  the  original  depth  of  the  socket  may  have  been. 
Indeed,  it  is  not  as  a  rule  necessary  to  penetrate  so  far. 

In  the  upper  jaw  the  principal  danger  in  making  a  socket  for  the 
reception  of  central  incisors  lies  in  the  proximity,  posteriorly,  of  the 
anterior  palatine  nerve,  artery,  and  vein,  which  have  their  exit  from  the 
bone  through  its  foramen,  often  near  the  roots  of  these  teeth.  With 
the  lateral  incisor  the  principal  precaution  necessary  is  the  preservation 
of  the  labial  plate  of  the  alveolus.  If  the  lost  tooth  has  been  absent 
for  some  time,  and  much  resorption  has  taken  place,  it  is  sometimes  im- 
possible to  drill  a  socket  so  that  the  tooth  has  a  proper  direction  and 


PREPARATION  OF  TEETH  FOR   PLANTATION.  655 

prominence  in  the  arch,  and  yet  be  able  to  secure  a  bone  covering  for 
its  labial  surface.  As  a  rule  there  is  sufficient  process  in  the  canine 
region  to  enable  the  operator  to  secure  all  the  attachment  desirable. 
The  bicuspid  and  molar  regions  present  the  danger  of  perforation  of  the 
floor  of  the  maxillary  sinus.  This  is  liable  ta  happen  anywhere  from 
the  first  bicuspid  to  the  second  molar.  Extreme  caution  should  be  ex- 
ercised to  avoid  it.  In  two  instances  in  practice  the  perforation  was  fol- 
lowed by  no  unpleasant  complications.  Care  was  taken  not  to  infect  the 
sinus,  the  teeth  were  implanted  in  the  usual  manner,  and  the  cases  re- 
sulted successfully.  Subsequently  one  of  these  teeth  was  lost,  but  dur- 
ing the  process  of  root  attachment  or  encystment  the  perforation  into 
the  sinus  was  closed. 

In  the  lower  jaw  the  principal  difficulties  encountered  are  the  follow- 
ing :  In  the  incisive  region  there  is  a  deficiency  of  alveolar  process,  and 
hence  much  difficulty  is  encountered,  at  times,  in  securing  a  sufficiently 
deep  bony  socket.  At  the  location  of  the  canine  tooth  the  lower  jaw 
becomes  broader  and  there  is  usually  sufficient  room  to  enable  the 
making  of  a  good  socket.  In  the  bicuspid  region  the  principal  pre- 
caution necessary  is  in  regard  to  the  mental  foramen.  It  must  be  borne 
in  mind  that  normally  the  exit  of  the  nerves  and  vessels  at  this  point 
is  directly  below  the  second  bicuspid  tooth  and  that  when  resorption  of 
the  alveolar  process  has  taken  place  this  foramen  is  often  near  the  upper 
border  of  the  jaw.  From  this  point  posteriorly  implantations  are  rarely 
performed,  and  when  done  the  principal  precaution  must  be  in  regard 
to  the  inferior  dental  canal,  which  is  near  the  surface  if  much  resorp- 
tion has  taken  place. 

Artificial  Crowns. — The  precautions  necessary  in  the  selection  of 
a  tooth  for  transplantation  or  implantation  have  been  noted,  and  it 
might  be  proper  at  this  time  to  describe  the  prepara- 
tion of  a  root  with  an  artificial  crown,  presuming  that 
it  is  only  in  rare  instances  that  a  suitable  entire 
natural  tooth  can  be  obtained.  Attention  was  called 
to  the  necessity  of  securing  asepsis  of  the  root,  and 
the  filling  of  the  root-canals  has  been  described.  The 
most  suitable  form  of  crown  has  been  found  to  be  the 
Logan,   which   is   ground   to   suit  the    occlusion  and       Natural  root  with 

,  .  artiticial  crown. 

cemented  into  the  root  canal  without  much  regard  as 
to  a  careful  fit  at  the  cervix  of  the  crown  to  the  root.  After  the 
cement  has  hardened,  the  margin  between  the  root  and  crown  is  pre- 
pared with  engine  burs,  and  a  filling  of  gold  introduced,  making  a 
circle  around  the  tooth.  When  this  is  polished  down  there  is  a 
perfect  gold  filling  level  with  the  root  and  crown,  which  is  preferable 
to  a  soldered  band.     (See  Fig.  580.) 


^56  PLANTATION  OF  TEETH. 

General   Considerations. 

Asepsis. — The  operations  descrilxd  in  tliis  (•lia])ter  must  always  be 
performed  under  perfect  aseptic  conditions ;  that  is,  the  hands  and 
person,  instruments  and  other  accessories,  the  tooth  about  to  be  phmted, 
iind  the  field  of  surgical  operation,  must  be  maintained  in  a  clean, 
aseptic  condition. 

Any  of  the  usual,  accepted  methods  can  be  resorted  to.  As  a  rule, 
however,  the  drugs  selected  for  this  purpose  should  not  be  of  an  irri- 
tating natiu'c.  For  the  hands  and  person,  pure  soap  followed  by  a  5 
per  cent,  solution  of  carbolic  acid  is  sufficient.  The  instruments  and 
other  accessories  can  be  kept  free  from  inoculating  bacteria  by  the  use 
of  pyrozone,  formalin,  euth  ymol,  or  a  5  per  cent,  solution  of  carbolic  acid. 
The  use  of  bichlorid  of  mercury  in  the  proportion  of  1  part  to  2000  of 
water  is  also  permissible,  although  it  is  not  as  advisable  on  account  of 
its  irritating  nature.  The  sterilization  of  the  tooth  about  to  be  planted 
differs  according  to  circumstances.  A  tooth  whose  source  is  unknown, 
and  which  has  been  kept  in  a  dry  state  for  a  long  period,  will  not  be 
benefited  by  being  placed  into  an  antiseptic  solution  until  just  prior  to 
the  time  when  it  is  to  be  used.  Hence  dry  teeth  can  be  kept  in  any 
clean  box  covered  with  clean  cotton  until  they  are  ready  for  use.  After 
the  necessary  preparation  hereinafter  described,  the  dry  tooth  should  be 
placed  in  a  solution  of  glycerol  and  carbolic  acid  (about  5  per  cent,  of 
the  latter),  and  just  before  using,  it  can  be  placed  in  a  pyrozone  solu- 
tion or  in  a  solution  of  carbolic  acid  and  water.  Freshly  extracted  teeth 
should,  of  course,  have  their  pulp  chambers  and  root  canals  cleansed 
and  hermetically  sealed,  and  then  be  placed  at  once  in  fluid,  preferably 
in  glycerol  to  which  a  few  drops  of  carbolic  acid  have  been  added. 

The  field  of  operation  may  be  quickly  sterilized  and  cleansed  of 
adhering  mucus  by  mopping  the  surface  with  a  ball  of  cotton  saturated 
with  hydrogen  dioxid  3  per  cent,  solution  just  previous  to  operating. 

It  is,  of  course,  of  exceeding  importance  that  the  socket  into  which 
a  tooth  is  about  to  be  planted  shall  be  free  from  disease  germs  or 
bacteria.  As  a  general  rule  flowing  blood  is  the  best  of  antiseptics, 
washing  away  any  bacteria  which  may  become  lodged  from  external 
sources,  hence  so  long  as  a  socket  is  constantly  being  filled  with  flow- 
ing blood  during  an  operation,  but  little  further  care  need  be  bestowed 
upon  it.  As  a  general  rule  the  socket  and  the  tissues  surrounding  it 
will  react  more  quickly  after  operation  the  less  the  medication  has  been  ; 
hence  the  very  slightest  and  mildest  of  antiseptics  are  indicated.  Zinc 
chlorid  2  to  5  grains  to  the  ounce  of  lukewarm  water,  hydrogen  dioxid 
3  per  cent.,  or  the  5  per  cent,  solution  of  carbolic  acid  in  lukewarm 
water,  give  most  satisfactory  results.  These  solutions  will  be  found 
quite  sufficient  to  maintain  the  field  of  surgical  operation  aseptic. 


GENERAL  CONSIDERATIONS.  .  657 

Anesthesia, — For  the  purpose  of  allaying  pain,  the  use  of  anes- 
thetics is  justified  when  imperatively  demanded,  but  unfortunately,  in 
the  plantation  of  teeth  the  benefits  derived  are  frequently  outweighed 
by  the  disadvantages  accruing  from  their  use. 

Anesthetics  are  either  general  or  local.  An  operator  would  scarcely 
be  justified  in  assuming  the  risks  attendant  upon  the  use  of  chloroform, 
ethylic  ether,  ethyl  bromid,  or  any  of  the  combinations  in  which  these 
anesthetics  are  administered.  Nitrous  oxid  would,  in  the  majority  of 
instances,  be  contra-indicated  by  reason  of  the  shortness  of  the  period 
of  anesthesia  which  it  induces. 

There  do  not  appear  to  be  any  records  of  satisfactory  results  with 
hypnosis.  That  field  is  open  to  the  intelligent  investigator  whose 
inclinations  lie  in  that  direction.  Local  anesthesia,  therefore,  is  the 
means  generally  employed.  The  use  of  cataphoresis  with  local  anes- 
thetics has  not  as  yet  been  satisfactory  for  this  purpose. 

The  method  adopted  has  usually  been  confined  to  the  injection  or 
other  introduction  of  cocain,  the  dose  being  variable,  but  usually  about 
5  to  15  minims  of  a  4  per  cent,  solution  of  the  hydrochlorid.  A  seri- 
ous objection  has  been  noted  to  injection  through  the  gum,  viz.  that 
more  or  less  sloughing  or  destruction  of  the  tissues  may  result,  and  this 
is  very  unfavorable  for  subsequent  success.  In  replantation  or  trans- 
plantation, sufficient  anesthesia  is  often  obtained  from  the  wash  used  in 
cleansing  the  socket ;  but  in  implantation  the  formation  of  the  new 
socket  is  often  an  exceedingly  painful  operation,  and  in  these  cases 
good  results  may  be  had  by  dipping  the  instrument  with  which  the 
socket  is  being  made,  into  crystals  of  cocain,  and  thus  by  the  friction 
of  the  instrument  rubbing  it  into  the  parts  that  are  being  operated 
upon. 

The  subject  of  anesthesia  may  be  dismissed  with  the  sole  injunction 
that  its  use  should  be  resorted  to  only  in  those  instances  wdiere  it  is 
absolutely  necessary.  The  majority  of  the  cases  of  plantation  are  per- 
formed with  no  more  pain  than  is  inflicted  in  filling  operations. 

The  same  care  should  be  given  to  the  retention  of  transplanted 
teeth  as  is  given  to  the  retention  of  replanted  teeth.  Teeth  thus 
carefully  transplanted,  in  individuals  of  good  health,  often  remain  as 
useful  members  for  a  number  of  years.  In  the  past  insufficient  atten- 
tion has  been  given  to  asepsis,  and  this,  coupled  with  the  fact  that  the 
root  had  not  always  been  properly  filled,  has  not  resulted  in  as  much 
success  as  is  attained  with  present  methods,  and  yet  transplanted  teeth 
are  known  to  have  remained  in  a  healthy  and  serviceable  condition 
for  from  twenty  to  forty  years. 

42 


658  PLANTATION  OF  TEETH. 

The  Operation  of  Implantation. 

Implantation,  in  order  to  yield  the  best  results,  should  be  confined 
to  mouths  which  are  habitually  clean  and  free  from  disease,  and  to  a 
part  of  the  individual's  life  during  which  the  power  of  the  developed 
mental  processes  is  not  impaired.  Unclean  personal  habits,  the  ex- 
cessive use  of  stimulants,  and  occupations  calling  for  an  unusual  ex- 
penditure of  nerve  force  are  unfavorable.  A  suitable  case  having  been 
selected,  an  impression  of  the  space  and  of  the  teeth  adjoining  it  is 
taken.  A  plaster  cast  is  made,  the  proper-sized  socket  drilled  therein, 
the  tooth  is  selected  and  prepared,  either  with  or  without  an  artificial 
crown  in  the  manner  previously  described,  the  occlusion  is  adjusted, 
and  a  retention  cap  is  made.  These  preliminaries  having  been  satis- 
factorily accomplished  the  case  is  ready  for  the  operation.  Under  the 
heading  of  General  Considerations  the  question  of  anesthesia  has  been 
already  treated. 

The  first  step  in  the  operation  is  the  making  of  an  incision  through 
the  gum  tissue.  A  number  of  different  kinds  of  incisions  have  been 
recommended  by  different  operators,  nearly  all  of  them  looking  toward 
the  preservation  of  the  largest  amount  of  gum  tissue.  Some  recom- 
mend a  crucial  incision  X,  turning  back  the  four  corners  of  the  gum 
tissue.  Others  have  recommended  an  incision  in  the  shape  of  the  letter 
H,  turning  back  the  two  flaps  thus  made. 

The  principal  objection  to  all  of  the  incisions  recommended  lies  in 
the  fact  that  they  all  look  toward  the  preservation  of  the  gum  tissue 
e{|ually  for  the  labial  and  lingual  surfaces  ;  Avhile,  as  a  matter  of  fact,  if 
proper  provision  is  made  for  the  protection  of  the  cervical  line  on  the 
labial  surface,  the  lingual  surface  will  take  care  of  itself,  for  it  will  be 
noticed  in  cutting  through  the  gum  tissue  that  it  is  much  thinner  where 
it  reflects  over  the  alveolar  border  upon  its  labial  aspect  than  upon  its 
lingual.  Hence,  frequently,  if  no  attention  whatever  has  been  paid  to 
the  retention  of  gum  tissue  on  the  lingual  surface,  the  neck  of  the 
tooth  will  nevertheless  be  sufficiently  protected. 

Fig.  581. 


Incision  In  gum  for  implantation. 


Another  serious  objection  to  an  incision  which  leaves  two  or  more 
points  or  margins  to  be  preserved,  is  that  the  tenacity  of  the  gum  tissue 


THE  OPERATION  OF  IMPLANTATION. 


659 


makes  it  utterly  impossible  to  preserve   these  various  flaps  and  projec- 
tions intact  from  the  cutting  instruments. 

The  writer's  method  consists  in  an  incision  resulting  in  one  flap, 
with  a  view  of  protecting  the  labial  surface  of  the  tooth  to  Ym.  583. 
be  implanted,  and  of  preserving  this  single  flap  from  in- 
jury during  the  progress  of  the  operation.  A  combina- 
tion, or  rather  a  modification,  of  the  most  suitable  incis- 
ions recommended  is  therefore  the  one  shown  in  Fig.  581. 
This  incision  is  made  with  ordinary  chisels  as  shown 
in  Fig.  582,  cutting  with  the  chisel  to  and 
including  the  periosteum,  lifting  it  for- 
1  \  m\  r  \  ward  and  holding  it  out  of  the  way  of 
the  operator  by  means  of  an  instrument 
similar  to  the  one  shown  in  Fig.  583. 

The  operation  thus  far  is  usually  sim- 
ple and  as  a  general  rule  not  very  pain- 
ful.    The   drilling   of  the   socket  varies 
with   diiferent   individuals   according    to 
Chisels  ^^^^   density  of   the  bone,  the   length  of 

time  that  the  tooth  has  been  out,  etc. 
In  some  instances  the  reamer  or  trephine  or  knife  pro- 
gresses rapidly,  while  in  others  progress  is  very  slow,  or 
sometimes  variable  as  the  instrument  enters  into  medul- 
lary spaces  or  passes  through  the  more  or  less  dense  parti- 
tions which  divide  these  medullary  spaces  from  each  other. 
The  operator  will  determine  during  the  operation,  by 
the  progress  he  is  making  with  different  instruments, 
which  are  the  best  to  use.  In  some  instances  the  entire 
socket  can  be  made  M'ith  an  ordinary  engine  bur,  while 
in  others  the  strongest  instruments  especially  designed  for 
implantation  are  none  too  strong.  In  some  instances  an 
instrument  which  clears  itself  well  during  one  operation 
clogs  annoyingly  during  another.  It  is  desirable  to  de- 
scribe at  this  point  the  various  useful  instruments  which 
have  been  designed  and  are  now  upon  the  market.  While 
all  of  them  are  not  necessary,  some  one  or  more  of  each 
class  are  indispensable.  The  trephines  of  Dr.  Younger, 
of  San  Francisco,  which  have  been  improved  by  Dr.  W. 
W.  Walker  of  New  York,  have  (as  shown  in  Fig.  584),  a 
set-screw  collar,  also  shown  detached,  which  slides  on  the 
shank  and  is  first  fixed  by  a  set-screw  as  a  gauge  of  the 
length  of  the  tooth  root.  As  will  be  noticed  the  trephines 
cut  only  on  the  edge,  and  hence  they  do  not  entirely  clear  themselves  ;, 


Instrument  for 
holding  flap 
during  the 
operation. 


660 


PLANTATION  OF  TEETH. 


tlio  reainors  described  on  a  previous  page  are  tlieu  used  to  remove  the 
core  and  enlarge  tlie  socket. 


Fig.  585. 


Younger-Walker  trephines. 


Rollins'  spiral 
knives. 


The  spiral  knives  (Fig.  585)  devised  by  Dr.  W.  H.  Rollins  of 
Boston  are  in  many  cases  very  useful. 

They  are  also  open  to  the  objection  of  clogging.  As  an  improve- 
ment upon  these  the  spiral  crib  knife  shown  in  Fig.  586  has  the 
advantage  of  permitting  the  core  to  pass  within  it. 


Fig.  586. 


Fig.  587. 


Fig.  588. 


^    (^    /tl    /fj^ 

m  111  ffi  m 
9  m  Ptl  HE 


Hi 


1 


Ottofy  spiral 
crib  knife. 


1  2 

Two  forms  of  Cryer's 
spiral  osteotome. 


12         3         4  5 

Ottolengui's  reamers. 


Dr.  R.  Ottolengui,  of  New  York,  has  devised  a  set  of  reamers  (Fig. 
588).  There  are  nine  leaves  to  each  reamer  and  each  leaf  is  divided 
into  five  teeth.  Three  of  the  leaves  reach  the  apex  of  the  cone  point 
and  thus  allow  a  more  ra])id  forward  drilling  into  the  bone.  A  sliding 
collar  forms  a  gauge  to  indicate  the  proper  depth  to  drill. 


THE  OPERATION  OF  IMPLANTATION. 


661 


The  reamers  designed  by  Dr.  Younger,  illustrated  in  Fig.  589,  are 
also  very  suitable  for  this  purpose.  Dr.  Cryer's  spiral  osteotome — two 
forms  of  which  are  shown  in  Fig.  587,  one  with  dentate  edges  the  other 
without — is  an  admirable  instrument  for  forming  the  artificial  socket. 

When  it  is  necessary  to  deepen  or  alter  the  shape  of  the  socket,  it  is 
done  very  simply  with  either  the  ordinary  burs  of  the  dental  engine  or 
what  is  preferable,  a  bur  with  a  long  shank  such  as  shown  in  the 
accompanying  illustration  (Fig.  590). 

Fig.  590. 


Dr.  Younger  s  reamers. 


12        3        4 
Engine  burs  with  long  sliank. 


The  following  are  to  be  recommended  :  Nos.  1  and  3  of  the  "Walker- 
Younger  trephines,  Nos.  1  and  3  of  the  Younger  reamers,  Nos.  1  and 
2  of  the  Rollins  spiral  knives,  Nos.  1  and  2  of  the  Ottofy  spiral  crib 
knives,  and  Nos.  1,  3,  and  4  of  the  Ottolengui  reamers  and  Cryer's 
osteotome. 

During  the  progress  of  the  drilling  of  the  socket,  the  tooth  should 
be  frequently  inserted  until  a  proper  adjustment  has  been  secured. 
Occasionally  these  teeth  can  be  implanted  and  so  perfectly  fitted  that  it 
is  almost  impossible  to  remove  them  with  the  unaided  fingers  ;  while  at 
times  the  bone  is  so  cancellated,  and  the  tissues  so  flabby,  that  a  socket 
drilled  never  so  carefully  will  not  retain  the  tooth  in  place.  Nothing 
is  gained  by  a  too  close  adjustment  of  the  root,  as  pressure  must  un- 
doubtedly be  exerted,  and  pressure  causes  resorption,  and  may  be  fol- 
lowed by  inflammation.  A  fair,  moderate  fitting  of  the  root  is  all 
that  should  be  aimed  at.  Just  before  the  final  adjustment  the  socket, 
gums,  tooth,  and  all  parts  contiguous  thereto,  should  be  placed  in  an 
aseptic  condition  and  the  cap  adjusted  in  the  manner  before  described. 
Though  the  tooth  may  be  adjusted  to  its  socket  so  that  immediately 
afterward  it  exhiV)its  much  firmness,  yet  in  a  few  days  subsequent  to 
the  operation  it  invariably  shows  less  rigidity  and  an  ajjparent  tendency 


662  PLANTATION  OF  TEETH. 

to  loosening'.  This  result  is  probably  due  to  the  resorption  of  those 
areas  of  contact  between  the  tootli  and  its  artificially  formed  alveolus 
\vliore  the  greatest  amount  of  pressure  is  exerted.  The  period  of 
loosening  is  generally  quickly  followed  by  a  ])rogressively  increasing 
firmness  and  immobility  of  the  tooth  caused  by  calcification  of  the 
exudate  thrown  out  by  the  walls  of  the  alveolus  in  the  process  of  I'epair 
of  the  surgical  injury  to  which  it  has  been  subjected  by  the  operation. 
Planted  teeth,  when  lost,  are  lost  as  a  rule  as  a  result  of  resorption  of 
their  roots.  The  process  seems  analogous  to  the  resorption  of  the 
roots  of  deciduous  teeth.  Present  records  seem  to  indicate  that  re- 
sorption of  the  roots  is  slowest  in  progress  in  replanted  teeth  ;  it  is 
more  ra})id  in  transplanted  teeth,  and  most  rapid  in  implanted  teeth. 
Intelligent  observation  over  replantations  and  transplantations  extends 
from  twenty  to  forty  years.  The  observation  of  Dr.  Younger  of 
implanted  cases  extends  at  this  writing  to  about  twelve  years,  and  he 
has  had  successful  cases  under  observation  which  have  remained  in  the 
mouth  over  ten  years.  The  writer  has  the  records  of  cases  which  have 
remained  and  done  good  service  for  ten  years. 


CHAPTER    XXIII. 

MANAGEMENT  OF  THE  DECIDUOUS  TEETH. 

By  Claek   L.  Goddaed,  A.  M.,  D.  D.  S. 


Eruption. — The  first  operation  the  dentist  is  called  upon  to  perform 
for  the  deciduous  (temporary)  teeth  is  lancing  the  gums  as  an  aid  to 
eruption  of  those  organs.  This  is  not  necessary  in  normal  but  only 
in  pathological  cases.  Although  gum  tissue  in  its  normal  condition  is 
comi)aratively  insensitive,  when  it  is  inflamed  it  is  exceedingly  tender. 

The  principal  source  of  pain,  however,  is  not  in  the  tissue  overlying, 
but  when  a  tooth,  bound  down  by  the  dense  gum  tissue  above  it,  by  its 
own  growth  presses  upon  the  formative  organ  below,  it  causes  pain 
which  in  many  cases  may  be  so  excessive  as  to  cause  reflex  disorders 
of  alarming  character. 

Dr.  J.  W.  White  ^  says  :  "  The  manifestation  of  functional  inharmony 
from  pathological  dentition  will  depend,  as  in  trouble  arising  from  any 
other  disturbing  cause,  upon  the  temperament  and  health  of  the  child, 
its  dietetic  management,  and  its  hygienic  surroundings.  In  some  cases 
there  is  a  gradual  development  of  biliary,  gastric,  enteric,  and  cerebral 
complications,  a  slow  but  steady  loss  of  vital  power,  with  no  effort  at 
recuperation  and  feeble  resistance  to  the  undermining  influences  which 
gradually  but  surely  wear  out  the  young  life. 

"  In  other  cases  the  indications  of  disturbance  of  function  are  mani- 
fested primarily  in  the  nervous  system  :  the  symptoms  are  all  charac- 
teristic of  acute  derangement  and  are  dangerous  from  their  violence 
and  uncontrollability.  High  fever,  vomiting,  choleraic  diarrhea,  men- 
ingitis, convulsions,  stupor  and  death  are  the  rapidly  succeeding 
phenomena.  Between  these  two  phases  there  is  every  conceivable 
grade  of  symptoms,  every  imaginable  complication." 

By  many,  as  an  objection  to  lancing  the  gums  it  has  been  urged  that, 
in  case  the  tooth  does  not  erupt  immediately,  cicatricial  tissue  is  formed 
over  it  which  will  bind  the  tooth  down  more  rigidly  than  before.  Cica- 
tricial tissue  is,  however,  of  a  lower  degree  of  organization  than  normal 
tissue,  and  is  more  easily  broken  down. 

^  Amer.  System  of  Dentistry,  vol.  iii.  p.  327. 

663 


664 


MANAGEMENT  OF  THE  DECIDUOUS  TEETH. 


Fio.  591. 


The  indications  for  interference  are  not  so  niucli  local  as  general — 
the  fretfnlness,  inability  to  sleep,  and  other  symptoms  mentioned  by 
Dr.  White.  The  gum  tissue  over  the  erupting  tooth  may  or  may  not 
be  highly  inflamed,  but  the  absence  of  such  infianunation 
does  not  contraindicate  lancing.  In  fact  some  of  the 
gravest  systemic  disturbances  occur  where  no  local  mani- 
festations are  evident. 

The  object  is  to  divide  the  gum  tissue  which  binds 
down  the  tooth  and  to  allow  it  free  egress.  The  most 
suitable  instrument  is  shaped  like  that  shown  in  Fig.  591 
and  sometimes  used  for  lancing  around  teeth  before  ex- 
traction. It  should  be  held  like  a  pencil  in  writing,  so 
that  one  or  more  fingers  can  form  a  rest  and  guide. 

For  operating  on  the  lower  jaw  the  child  is  best  seated 
in  the  lap  of  the  operator  with  the  head  against  his  breast. 
By  passing  the  left  arm  around  the  infant's  head  and  in- 
serting the  left  thumb  in  its  mouth  with  the  fingers  under 
the  chin,  the  lower  jaw  can  be  held  rigidly  while  the  right 
hand  performs  the  oj)eration. 

For  operating  on  the  upper  jaw  it  is  best  to  lay  the  child 
across  on  the  nurse's  lap.  The  operator  takes  the  head  on 
or  between  his  knees,  opens  the  mouth  by  inserting  one  or 
more  fingers  of  the  left  hand,  and  holds  the  thumb  and 
forefinger  on  each  side  of  the  alveolar  ridge,  thus  prevent- 
ing injury  to  contiguous  parts  during  possible  struggles 
of  the  child. 

For  incisors  a  simple  longitudinal  incision  is  made,  a 
little  longer  than  the  cutting  edge  of  the  tooth.  The 
lancet  should  be  sharp,  so  as  to  easily  penetrate  to  the 
tooth.  No  harm  will  be  done  except  to  the  blade  of  the 
lancet.  For  the  canines  a  single  incision  is  good,  but  a 
crucial  incision  is  better.  Sometimes  lancing  is  necessary 
for  the  canine  after  it  is  partially  erupted,  as  the  gum 
tissue,  pierced  by  the  point  only  of  the  tooth,  may  form  a 
dense  ring  around  this  point  and  interfere  with  further 
eruption.  In  such  a  case  a  division  of  this  ring  in  two  or 
more  opposite  places  will  give  relief. 

For  the  molars  a  crucial  incision  is  best,  one  cut  ex- 
tending from  the  posterior  buccal  to  the  anterior  lingual 
cusp,  and  the  next  from  the  posterior  lingual  to  the  ante- 
rior buccal.  Sometimes  lancing  is  necessary  for  these 
teeth  after  partial  eruption.  After  the  cusps  have  pierced  the  gum, 
the  tooth  may  be  held  back  by  the  bands  of  tissue  in  the  sulci.     In 


Gum  lancet. 


ERUPTION  AND  DURATION.  '665 

such  cases  division  of  these  bands  in  the  same  direction  as  before  de- 
scribed for  an  unerupted  tooth  will  give  relief.  Sharp-pointed  curved 
scissors  are  well  adapted  to  this  latter  operation. 

Fig.  592  Avill  illustrate  the  direction  of  the  incisions  described.  The 
relief  aiforded  is  generally  immediate.  In  one  case  a  child  who  had 
been  fretful  for  several  days,  and  who  had  not  slept  at  all  during  the 
day,  was  asleep  in  the  writer's  arms  within  five  minutes  after  the  ope- 
ration.    The  gum  tissue  is  not  very 

sensitive,    so    the    operation    is  often  ^^'       "  ^^^^ 

painless.       The    little    sufferer    will  .^^\^a 

often    recognize    the    relief    obtained  %l  /^ 

and   point   to  other  portions  of  the  1"\/^ 

gums  for  further  relief.  ,ili^  /  ,i 

Duration    of  the    Deciduous  ^ti^     '  ^  * /-w*/  / 

Teeth. — The    importance    of    filling     ^       -  ^  ^^^^  ^         -'*>-',  ^ 
cavities   in   the  children's  temporary         "^i^  "^^^S^^ 

teeth   is   often    overlooked,  even   by  -=^  ^    \ 

dentists  themselves,  as  these  teeth  are  Lines  of  incision  in  lanclng :  a,  a,  over  the 

,     J        I         I      ,                    ■■               ,  molars ;  6, 6,  over  the  canines  and  incisors 

supposed    to     be     lost    so    early    as    to  before  eruption :  c,  c,  c,  over  the  molars 

render    such    operations     Unnecessarv.  an«5  canines  after  partial  eruption  (J.  w. 

r^,  .      .                    11                       •  1       1        -■'  White). 

This  is  generally  true  with  the  in- 
cisors, is  less  true  with  the  canines,  while  the  molars  often  need  at- 
tention. Fig.  541  (see  Chapter  XXI.)  shows  the  relations  of  the 
deciduous  to  the  permanent  dentures  in  a  child  of  about  six  years 
of  age.  A  study  of  the  following  table  will  show  that  while  the 
incisors  are  superseded  early  by  their  successors  the  molars  are  in 
place  nearly  twice  as  long : 

Time  of  Eruption.  Loss.  Duration. 

Central  incisors 6-8  months.  6th-7th  year.         5i  to  6J  years. 

Lateral       7-9  "                       7th-8th "  «           u   «    ,;    \c 

First  molars      14-16  "                       9th-10th  "           7^"    9      " 

(1  yr.   2  m.-l  yr.  4  m.) 

Canines 17-18  "          flnf.     8th-10th  " 

(liyrs.)  tSup.lltli-12th  "           7     "   10   " 

Second  molars 18-24  "                     12th-13th  "        10     "   11    " 

(\\  yrs.-2yrs.) 

The  temporary  molars  should  be  preserved  for  three  reasons : 

1st.  To  prevent  the  child  suffering  pain. 

2d.  To  allow  proper  mastication  of  food. 

This  latter  is  of  extreme  importance,  as  these  years  are  especially 
important  ones  in  the  child's  growth.  If  he  is  prevented  by  pain  from 
properly  masticating  his  food  it  will  not  be  assimilated,  and  a  habit  of 


666 


MANAGEMENT  OF  THE  DECIDUOUS  TEETH. 


s\v;illi)\\  inii'  food  without  masticating  may  be  continued  even  when  the 
permanent  teeth  have  erupted. 

3d.  To  preserv^e  the  fuhiess  of  the  areli   for  the  permanent  teeth. 

Early  loss  of  the  deciduous  second  molar  will  alhjw  the  first  per- 
manent molar  to  move  forward  and  (xxnipy  room  that  should  be  pre- 
served by  the  bicuspids.  Early  loss  of  the  first  temporary  molar  will 
allow  the  second  temporary  and  the  first  permanent  molar  to  move 
forward. 

The  crowns  of  the  temporary  molars  are  much  larger  than  the 
necks,  and  caries  of  the  approximal  surfaces  will  allow  them  to  crowd 
together  with  the  same  result.  Approximal  fillings  inserted  should  be 
so  shaped  as  to  preserve  the  original  contour.  If  the  first  permanent 
molar  thus  moves  forward  of  its  natural  position  a  smaller  arch  is  left 
for  the  successional  teeth.  The  result  may  be  a  constricted  arch,  a 
pointed    arch,    upper  protrusion,  or    the    labial    displacement  of    the 

canines. 

Fig.  593.1 

k 


Decalcification  of  the  deciduous  teeth.    The  numbers  indicate  years. 

Odontalgia. — The  first  visits  by  children  are  usually  for  the  relief 
of  "  toothache,"  and  may  occur  at  any  age  from  two  years  upward. 

The  first  treatment  of  most  children's  teeth  should  be  palliative. 
In  many  cases  a  fear  of  the  dentist  has  been  engendered,  which  it  should 
be  the  prime  object  to  remove.  Make  the  acquaintance  of  the  little 
patient  in  the  reception  room,  talking  perhaps  of  things  altogether 
foreign  to  the  case  in  hand,  and  distract  its  attention.  If  the  child  is 
very  timid  examine  the  teeth  while  it  is  seated  in  an  ordinary  chair,  or 
in  its  parent's  lap,  and  apply  some  dressing  to  relieve  the  pain. 

In  the  operating  room  the  chair  should  be  adjusted  to  its  smallest 
size ;  a  special  child's  seat  may  be  used,  or  a  cushion  half  the  size  of  the 
chair  seat,  and  not  too  soft.  The  child's  head  should  be  made  comfort- 
able in  the  head-rest.  The  operator  should  not  let  the  child  detect  him 
in  an  endeavor  to  hide  instruments  ;  the  necessary  ones  may  be  shown 
to  him  if  they  arouse  his  curiosity,  and  their  purpose  explained. 

1  Prof.  Pierce  in  Amer.  System  of  Dentistry,  vol.  iii.  p.  639. 


ODONTALGIA.  667 

On  account  of  the  diffieultv  the  child  has  in  making^  himself  under- 
stood,  or  from  his  not  knowing  what  he  wishes  to  describe,  diagnosis  is 
difficult.  A  child  cannot  always  distinguish  just  Avhere  pain  is  felt,  nor 
always  remember  its  exact  location.  In  most  cases  the  first  occurrence 
of  pain  is  during  mastication. 

It  is  necessary  to  ascertain  whether  pain  is  caused  by  an  erupting 
tooth,  a  nearly  exposed  pulp,  a  pulp  inflamed  and  dying,  a  putrescent 
pulp,  or  an  alveolar  abscess.  If  the  nearly  exposed  pulp  is  suspected, 
test  it  by  the  application  of  a  drop  of  cold  water.  Pain  during  masti- 
oatioii  may  be  caused  by  thermal  changes,  by  pressure  of  food  in  the 
€avity,  or  by  pressure  on  a  tooth  whose  pericementum   is  inflamed. 

If  the  tooth  is  aching  while  the  child  is  in  the  chair,  syringe  out  the 
€avity  with  warm  water,  dry  it  with  bibulous  paper,  and  apply  a  pledget 
of  cotton  saturated  with  oil  of  cloves,  campho-phenique,  or  whatever 
has  been  found  effective  with  permanent  teeth.  Fletcher's  carbolized 
resin  ^  has  been  invaluable  for  this  purpose  in  the  writer's  practice. 
Applied  on  a  pellet  of  cotton  it  acts  as  an  anodyne,  and  the  resin 
hardens  in  the  cotton,  forming  with  it  a  temporary  stopping  which  will 
even  bear  the  force  of  mastication  for  a  few  days.  It  is  sometimes 
best  to  renew  this  dressing  a  few  times  before  attempting  a  more  per- 
manent treatment  or  filling. 

If  the  child  cannot  be  brought  to  the  office  again  within  a  few  days, 
let  the  parent  provide  himself  with  a  bottle  of  the  carbolized  resin  and 
an  inexpensive  pair  of  dressing  pliers.  Instruct  the  patient  how  to 
apply  the  cotton  dressing.  This  is  the  best  domestic  remedy  for  odon- 
talgia. Other  medicaments  may  be  used  by  the  parent,  such  as  oil  of 
cloves,  campho-phenique,  etc.,  but  their  effect  is  much  more  temporary. 
A  more  durable  dressing  may  be  made  by  mixing  zinc  oxid  and  car- 
bolized resin  to  the  consistence  of  putty  and  applying  it  in  the  cavity 
previously  dried.  It  hardens  under  moisture,  and  makes  a  stopping 
that  will  remain,  in  some  cases,  for  several  weeks. 

During  such  palliative  treatment,  sometimes  unavoidably  extended 
over  several  weeks  or  even  months,  the  child  is  growino-  older,  is  p-ain- 
ing  experience,  is  becoming  used  to  manipulation,  begins  to  recognize 
the  benefit  of  treatment  of  the  teeth — in  a  word,  is  being  trained  or 
educated  for  a  good  patient  for  whom  more  permanent  operations  may 
be  attempted. 

Prof.  I>.  L.  Dunbar  savs  :    "  As   a    domestic    palliative    always   at 

hand,  in  the  treatment  of  pulp  exposure  and  restricting  odontalgia,  use 

ammonia  on  cotton  :  its  repeated  use  will  devitalize  the  pulp,  at  the 

same  time  effecting  its  removal  by  saponification." 

^  Carbolic  acid, 
Resin  (colophony),  da.  5J  ; 

Chloroforna,  i.^ss. 


668  MANAGEMENT  OF  THE  DECIDUOUS  TEETH. 

Treatment  with   Silver  Nitrate. 

More  than  forty  years  ago  tlic  application  of  silver  nitrate  for 
arresting  decay  was  advocated,  but  for  many  years  no  notice  was  taken 
of  it.  Within  the  last  five  years  it  has  been  advocated  again,  especially 
for  use  in  the  temporary  teeth.  The  fact  that  it  blackens  the  decayed 
surface  is  not  as  objectionable  as  with  permanent  teeth.  Dr.  Stebbins ' 
advocated  the  use  of  a  solution  of  the  crystals  of  silver  nitrate  in  cari- 
ous (cavities  in  temporary  teeth.  He  applies  it  by  means  of  a  small 
stick  inserted  in  a  socket  instrument  as  shown  in  Fig.  594.      Many 

Fig.  594. 


cases  will  need  no  further  treatment,  decay  being  completely  arrested. 
Some  cases  will  need  secondary  treatment  after  a  few  months.  In 
many  cases  he  advises  filling  the  cavity  with  gutta-percha  after  the 
application. 

Dr.  C.  N.  Peirce^  advises  saturating  pieces  of  blotting  paper  with 
40  per  cent,  solution  of  silver  nitrate,  and  keeping  these  on  hand  for 
use. 

Dr.  E.  C.  Kirk  advises  the  use  of  asbestos  felt  for  saturation  with 
the  solution  in  preference  to  blotting  paper  or  cotton.  He  says  :^  "  The 
contact  of  silver  nitrate  with  vegetable  fiber  of  any  sort  involves  not 
only  a  destruction  of  the  fiber  but  also  of  the  silver  nitrate,  so  that  the 
preparation  in  a  short  time  loses  its  desirable  qualities."  He  advises 
that  the  asbestos  felt  be  heated  before  the  blowpipe  before  saturation^ 
to  burn  out  any  organic  material  which  may  be  present. 

Dr.  A.  M.  Holmes  "*  advises  its  use  as  follows  for  approximal  cavities  : 
"  Cut  away  the  walls  to  a  V  shape,  and  with  a  piece  of  gutta-percha, 
softened  by  heat,  of  the  proper  size  to  fill  the  space,  bring  the  surface 
to  come  in  contact  with  the  diseased  part  of  the  teeth,  into  contact  with 
the  powdered  crystals  of  silver  nitrate  and  carry  it  to  the  place  in  the 
tooth  or  teeth  prepared  for  its  reception,  packing  it  firmly  and  leav- 
ing it  there  to  be  worn  away  by  use  in  mastication.  When  that  takes 
place,  the  surfaces  of  the  teeth  treated  will  be  found  black  and  hard, 
with  no  sensitiveness  to  the  touch  or  to  change  of  temperature,  and 
they  will  remain  so  indefinitely.     In  case  the  child  is  so  timid  as  to 

1  International  Dental  Journal,  1891,  p.  661.  ^  Ibid.,  1893,  p.  152. 

3  Dental  Cos7nos,  1893,  p.  667.  *  Ibid.,  1892,  p.  982. 


FILLING  MATERIALS.  669 

prevent  this  course,  dry  the  cavity,  take  out  as  much  softened  dentin 
as  the  patient  will  permit,  carry  the  crystals  on  softened  gutta-percha 
into  the  cavity  and  pack  it,  leaving  it  until  such  time  as  desirable  to 
make  a  more  thorough  operation." 

In  the  writer's  opinion  it  is  better  to  open  approximal  cavities  from 
the  occlusal  surface  rather  than  make  V-shaped  spaces,  as  the  full 
diameter  of  the  teeth  should  be  left  to  preserve  the  fulness  of  the 
urch. 

Silver  nitrate  in  its  action  penetrates  but  a  short  distance. 

The  Character  of  the  Patient. 

The  conditions  of  operating  on  the  deciduous  teeth  vary  so  much 
from  those  pertaining  to  the  permanent  teeth  that  a  different  consid- 
eration must  be  taken  of  filling  materials. 

The  little  patients'  mouths  are  small.  They  are  often  too  young  to 
reason  with  or  to  understand  the  purpose  of  the  operation.  They  have 
been  too  often  frightened  by  thoughtless  remarks  of  their  elders  in 
speaking  of  their  dentist. 

Oftentimes  the  first  sitting  must  be  utilized  merely  to  make  the 
acquaintance  of  the  child,  perhaps  cleaning  the  teeth  a  little,  or  intro- 
ducing some  palliative  dressing  in  an  aching  tooth.  The  greatest  care 
should  be  taken  not  to  hurt  the  child.  After  it  has  gained  a  little 
experience  it  recognizes  the  benefit  of  the  treatment,  and  will  often 
.submit  to  operations  that  older  patients  even  shrink  from. 

Filling  Materials. 

Gutta-percha. — Pink  base-plate  gutta-percha  is  a  most  valuable 
filling  material.  In  approximal  cavities  where  it  is  not  exposed  to 
wear  and  A\here  the  sha})e  of  the  cavity  is  such  as  to  retain  it,  it  is 
practically  indestructible.  In  occlusal  and  compound  cavities  in  which 
it  is  exposed  to  wear  it  has  wonderful  durability,  lasting  in  some  cases 
for  several  years. 

Directions  for  Use. — Cut  the  gutta-percha  in  small  pieces  and  place 
them  on  a  gutta-percha  warmer  (see  Fig.  304),  where  they  can  be  kept 
soft  but  not  heated  enough  to  injure  the  material.  The  instruments 
also  should  be  warmed  (see  Fig.   293). 

Occlusal  Cavities. — Cut  away  the  margins  of  thin  enamel  with 
suitably  shaped  chisels,  and  remove  the  decayed  and  softened  dentin 
with  scoop  and  hatchet  excavators.  Do  this  as  thoroughly  as  the 
patient  will  permit,  but  do  not  sacrifice  the  patient  to  thoroughness,  for 
the  thorough  removal  of  softened  dentin  is  not  as  essential  as  with  per- 
manent teeth,  because  the  gutta-percha  is,  by  mastication,  kept  in  such 


670  MANAGEMENT  OF  THE  DECIDUOUS  TEETH. 

accurate  contact  with  all  the  walls  of  the  cavity  that  further  soften- 
ing will  go  on  very  slowly  if  at  all.  No  special  attention  need  be  paid 
to  the  form  of  the  cavity,  except  that  its  mouth  should  not  be  larger 
than  the  rest,  nor  should  any  parts  of  the  cavity  be  inaccessible  to  the 
filling  material.  After  excavating,  dry  the  cavity  with  bibulous  paper, 
and  apply  camph()-j)ht'ni(pu',  oil  of  cloves,  or  carbolic  acid,  to  sterilize 
any  softened  dentin  which  may  not  have  been  removed.  For  drying 
cavities,  prepare  paper  cylinders,  of  different  sizes,  as  follows  :  Tear 
the  bibulous  pai)er  in  strips  from  half  an  inch  to  two  inches  in  width, 
lioll  or  twist  each  of  these  strips  into  a  rope,  but  not  too  tightly — just 
enough  to  retain  the  shape.  Cut  these  ropes  into  cylinders  from  a 
quarter  to  half  an  inch  in  length.  Some  of  these  will  be  as  large 
around  as  a  lead  pencil  and  others  no  larger  than  the  lead  itself. 

Protect  the  tooth  from  moisture  as  well  as  possible.  For  lower 
cavities  fold  a  small  napkin  diagonally  from  the  corner  till  it  is  about 
half  an  inch  wide.  Put  the  end  of  this  between  the  gum  of  the  upper 
canine  and  the  lip  and  extend  the  napkin  back  between  the  upper 
molars  and  the  cheek  beyond  the  last  tooth,  then  down  behind  the  last 
lower  molar,  and  press  it  between  the  lower  teeth  and  tongue.  Tell 
the  patient  to  raise  the  tongue  as  it  is  applied,  tlien  to  lower  the  tongue 
and  hold  the  napkin  wdth  it.  The  part  of  the  napkin  between  the 
upper  teeth  and  the  cheek  will  cover  the  mouth  of  the  duct  of 
Steno,  and  prevent  or  absorb  the  flow  of  saliva.  It  is  better  to  cover 
the  mouth  of  this  duct  with  a  piece  of  spunk  about  half  an  inch  in 
diameter  before  applying  the  napkin.  The  folds  of  napkin  between 
the  lower  teeth  and  tongue  and  under  the  tongue  will  absorb  the  saliva 
from  the  submaxillary  glands.  This  part  of  the  napkin  can  be  held  in 
place  with  a  mouth  mirror  or  other  blunt  instrument,  by  the  operator 
or  assistant.  After  applying  the  napkin  use  a  large  bibulous  paper 
cylinder  to  absorb  the  moisture  from  the  tooth  to  be  filled  and  also 
from  contiguous  ones.  With  smaller  cylinders  or  pellets  dry  the  cavity. 
Apply  once  more  campho-phenique  or  other  medicament,  and  absorb 
the  excess. 

The  gutta-percha  having  been  meanwhile  warmed  and  softened, 
pick  up  a  small  piece  of  it  with  a  cold  round-pointed  instrument 
and  press  it  into  the  cavity.  If  the  cavity  is  not  large,  a  single 
piece  of  gutta-percha  of  a  diameter  less  than  that  of  the  cavity,  but 
longer  than  the  cavity  is  deep,  can  be  pressed  in  quickly  and  at  one 
movement.  For  medium-sized  cavities  select  a  piece  of  gutta-percha 
large  enough  to  cover  the  floor  of*  the  cavity  and  press  it  into  place 
with  a  cold  instrument,  as  a  Avarra  instrument  might  drag  it  from  its 
place.  Add  similar  pieces,  pressing  each  one  to  the  place  in  which  it  is 
to  remain,  till  the  cavity  is  full.     If  at  any  time  the  gutta-percha  in  the 


FILLISG  MATERIALS.  671 

cavity  becomes  so  hard  as  to  lose  its  plasticity,  apply  a  warm  instrument 
to  soften  the  surface,  so  that  the  next  piece  will  adhere  to  the  others. 
As  the  filling  nears  completion  select  a  small  piece  for  the  last,  just 
large  enough  to  complete  the  filling  and  no  more,  so  that  none  will 
have  to  be  trimmed  away,  for  in  trimming  the  surplus  away  the  filling 
may  be  drawn  from  contact  with  the  walls  of  the  cavity. 

In  filling  large  cavities  it  may  be  necessary  to  hold  the  first  piece  in 
position  with  another  instrument  till  sufficient  material  is  added  for  self- 
retention.  At  the  completion  of  the  filling  slight  pressure  with  a  warm 
instrument  should  be  made  in  such  a  manner  as  to  force  the  material 
against  all  the  margins  of  the  cavity. 

Appeoximal  Cavities, — Where  possible,  approximal  cavities 
should  be  opened  from  the  buccal  surfaces,  as  advised  by  Dr.  Bon- 
will,  as  in  such  cases  gutta-percha  fillings  will  not  be  exposed  to  the 
force  of  mastication.  This  plan  is  not  often  practicable  because  the 
patient  is  seldom  presented  till  the  cavity  has  become  visible  by  open- 
ing into  the  occlusal  surface  of  the  tooth.  In  such  cases  cut  away  the 
enamel  only  enough  to  give  access  to  the  cavity,  excavate  the  decayed 
dentin,  and  trim  the  buccal,  lingual,  and  cervical  walls  until  a  smooth, 
firm  margin  is  obtained. 

In  filling  such  a  cavity  use  small  pieces  of  softened  gutta-percha, 
pressing  each  piece  where  it  is  to  remain,  and  avoid  a  surplus.  Press 
the  gutta-percha  against  the  adjoining  tooth  as  if  it  were  a  matrix  or  a 
fourth  wall  of  the  cavity  and  let  it  remain.  It  is  useless  to  trim  it 
away  from  the  adjoining  tooth,  because  the  force  of  mastication  would 
soon  spread  the  filling  against  it  again. 

If  an  approximal  cavity  cannot  be  readily  shaped  so  that  it  will 
retain  the  gutta-percha,  it  may  be  packed  against  the  adjoining  tooth, 
as  if  it  were  an  occlusal  cavity.  It  will  prevent  decay,  especially  if  sil- 
ver nitrate  is  applied  as  described  on  page  668,  and  may  be  retained  till 
the  patient  is  older,  when  a  more  thorough  operation  may  be  performed. 

The  spreading  of  the  gutta-percha  by  the  force  of  mastication  will 
tend  to  separate  the  teeth — which  is  sometimes  an  advantage  ;  and  also 
to  press  upon  the  gum  in  the  interproximal  space — which  is  a  disad- 
vantage. In  filling  children's  teeth  we  cannot  always  reach  the  ideal, 
but  must  select  the  method  and  material  which  will  have  the  greatest 
advantage  Avith  the  least  disadvantage.  If  the  teeth  separate  so  much 
that  the  pressure  of  the  gutta-percha  upon  the  gum  tissue  becomes  a 
serious  annoyance,  some  other  material  must  be  substituted.  Zinc 
phosphate  cement  is  probably  the  best. 

To  prevent  the  impinging  of  the  gutta-percha  upon  the  gum  in  the 
interproximal  space,  Dr.  M.  W.  Hollingsworth  ^  has  invented  a  space 
^  Dental  Cosmos,  1S96,  vol.  xxxviii.  p.  553. 


«72 


MANAGEMENT  OF  THE  DECIDUOUS  TEETH. 


guard,  consisting  of  a  concave  elliptical  j)iece  of  metal  coated  on  the 
convex  surface  with  gutta-percha.  This  guard  is  to  bridge  over  the 
interproximal  space.  It  is  placed  in  position  with  the  instrument 
shown  in  B,  Fig.  595,  which  is  warmed  slightly,  so  that  the  point  can 


Fig.  595. 


Fig.  596. 


-enter  a  small  hole  in  the  guard  and  adhere  to  the  gutta-percha  on  the 
under  side,  as  shown  at  c.  The  guard  is  placed  in  the  cavities,  after 
warming  the  gutta-percha,  as  shown  in  Fig.  596,  and  thus  covers  the 
cervical  borders.  Gutta-percha  is  now  filled  in  over  the  guard  as  if 
the  two  cavities  formed  a  single  crown  cavity. 

Advantages  of  Gutta-percha. — It  is  easily  applied  to  the  cavity;  it  is 
insoluble  ;  is  durable  even  when  masticated  upon  ;  is  a  non-conductor  of 
thermal  impulses  ;  the  filling  is  finished  as  soon  as  the  cavity  is  full ;  it 
spreads  under  the  force  of  mastication,  and  is  thus  kept  in  contact  with 
the  walls  of  a  cavity  ;  it  can  be  used  even  under  moisture. 

Disadvantages. — Gutta-percha  is  softer  than  other  filling  materials, 
and  hence  wears  away  more  rapidly.  In  approximal  cavities  it  will 
spread  the  teeth  apart,  and  may  then  press  upon  and  irritate  the  gum. 

Dryness  of  the  cavity,  though  very  desirable,  is  not  absolutely  neces- 
sary. 

Advantages  of  Zinc  Phosphate  Cement. — It  is  a  poor  conductor  of 
heat ;  it  withstands  the  force  of  mastication  better  than  gutta-percha ; 
it  adheres  to  the  walls  of  the  cavity,  and  hence  will  remain  where  no 
other  material  can ;  it  is  easily  applied  ;  its  color  may  be  selected  to 
match  the  tooth. 

Disadvantages. — Absolute  dryness  of  the  cavity  is  a  prerequisite  to 
its  success ;  it  must  be  kept  dry  for  several  minutes  after  it  is  inserted 
in  the  cavity.  Zinc  phosphate  cement  disintegrates  in  some  mouths 
much  more  rapidly  than  in  others.  If  placed  too  near  the  pulp  it  may 
by  chemical  irritation  devitalize  it. 


FILLING   MATERIALS.  673 

Application  of  the  Rubber  Dam. — While  many  hesitate  to  attempt 
the  use  of  the  rubber  dam  with  children,  it  will  be  found  upon  trial  that 
most  of  them  will  submit  to  it  without  trouble,  and  many  will  prefer  it 
to  other  means  of  keeping  cavities  dry. 

Although  there  is  an  advantage  in  applying  the  rubber  dam  before 
excavating — because  dryness  makes  the  teeth  less  sensitive,  and  a  clearer 
view  of  the  cavity  is  obtained — still,  for  the  sake  of  not  tiring  the  little 
patients  by  too  long  restraint  in  one  position,  it  is  better  to  do  most  of 
the  excavating  before  its  application. 

The  small  size  of  the  necks  of  the  deciduous  teeth  compared  with 
that  of  the  crowns  renders  the  retention  of  the  rubber  dam  easier  than 
with  permanent  teeth.  Even  considering  the  smallness  of  the  patients' 
mouths,  the  application  of  the  rubber  dam  is  not  difficult  in  many 
cases. 

For  retaining  the  rubber  dam  on  the  second  molar  a  clamp  will 
sometimes  be  necessary,  but  for  the  other  deciduous  teeth  a  floss  silk 
ligature  will  be  sufficient.  Having  punched  holes  of  suitable  size 
through  the  rubber  dam,  apply  it  over  the  teeth  aflected.  If  the  cavity 
is  in  the  occlusal  or  buccal  surface  only,  it  will  not  be  necessary  to 
apply  it  over  more  than  one  tooth,  but  if  the  cavity  is  in  the  approximal 
surface  it  will  be  necessary  to  apply  the  rubber  dam  over  two  or  some- 
times three  teeth,  or  even  more,  if  several  cavities  are  to  be  filled  at  one 
sitting. 

It  is  not  always  necessary  to  tie  a  ligature  around  the  neck  of  the 
tooth,  as  merely  passing  the  waxed  floss  silk  between  the  teeth  will 
often  force  the  rubber  around  the  neck  of  the  tooth  enough  to  retain  it 
even  above  an  approximal  cavity.  The  silk  may  then  be  removed  by 
drawing  the  end  through  between  the  teeth. 

With  a  thin  burnisher  or  spatula  turn  up  the  edge  of  the  rubber 
around  the  neck  of  the  tooth  toward  the  gum.  The  tendency  of  the 
rubber  then  will  be  to  slide  in  that  direction  and  not  off  over  the 
crown.  If  a  ligature  be  necessary  to  hold  the  rubber  above  the  edge  of 
an  approximal  cavity  tie  it  tightly  around  the  neck  of  the  tooth,  even 
forcing  it  toward  or  under  the  edge  of  the  gum  with  an  instrument  when 
necessary.  The  clamp  on  a  second  molar  may  often  be  dispensed  with 
after  a  ligature  is  applied,  unless  it  is  needed  to  hold  the  rubber  out  of 
the  operator's  way.  The  only  object  in  omitting  the  clamp  is  to  pre- 
vent pain  or  discomfort  to  the  child. 

If  a  simple  ligature  will  not  retain  the  rubber  on  a  second  molar 
before  the  first  permanent  molar  has  appeared,  its  efficiency  may  be 
greatly  increased  by  stringing  a  bead,  about  an  eighth  of  an  inch  or  less 
in  diameter,  on  the  thread  and  tying  a  simple  knot  in  it  so  that  the  bead 
will  be  in  about  the  middle  of  the  ligature.     Tie  the  ligature  around 


674  MANAGEMENT  OF  THE  DECIDUOUS  TEETH. 

the  tooth  so  that  the  bead  will  lie  against  the  distal  surface  of  the 
second  molar  on  or  near  the  gum.  This  bead  will  prevent  the  rubber 
slipping  oif  the  tooth.  A  short  cylinder  of  bibulous  paper  can  be  tied 
in  the  ligature  and  ai)p]i<'d  with  the  same  effect,  and  even  a  large  knot 
in  the  ligature  on  the  distal  surface  of  the  tooth  will  often  answer  the 
purpose. 

The  corners  of  tiie  rul)b(>r  dam  should  be  held  out  of  the  way  by  a 
suitable  holder  extending  around  the  head.  The  lower  border  may  be 
held  out  of  the  operator's  way  by  small  weights,  hooked  in  the  edge. 

Dry  the  cavity  and  the  whole  tooth  or  teeth,  and  complete  the 
excavation. 

Pilling-  Cavities  with  Cement. — As  cement  can  be  applied  easily 
in  undercuts  and  very  irregularly  shaped  cavities  it  is  not  necessary  to 
cut  away  the  enamel  more  than  is  sufficient  to  enable  the  operator  to 
thoroughly  remove  the  disintegrated  dentin.  Even  the  thorough  re- 
moval of  the  latter  is  not  as  essential  for  a  cement  filling  as  for  other 
materials,  for,  if  the  edge  of  the  cavity  can  be  made  smooth  and  the 
softened  dentin  be  thoroughly  sterilized,  the  cement  will  hermetically 
seal  it  and  prevent  further  disintegration  until  it  is  worn  away  beyond 
the  sound  edges. 

The  operator  may  take  much  greater  risks  in  leaving  disintegrated 
dentin  than  with  permanent  teeth,  for  the  object  is  simply  to  retain  the 
tooth  till  the  time  arrives  for  its  successor  to  appear. 

It  must  be  remembered  in  excavating  cavities  in  deciduous  teeth 
that  the  pulp  is  much  larger  in  proportion  to  the  size  of  the  crown  than 
in  permanent  teeth,  and  that  in  trying  to  make  undercuts  or  retaining 
grooves  deep  enough  to  retain  a  filling,  the  pulp  may  be  exposed — an 
accident  which  should  be  carefully  guarded  against,  for  the  pulp  has 
not  even  the  recuperative  power  possessed  by  the  pulp  of  a  permanent 
tooth,  and  in  case  of  its  death  it  is  more  difficult  to  give  a  deciduous 
tooth  proper  treatment.  Moreover,  death  of  the  pulp  prevents  normal 
resorption  of  the  root  and  may  thus  cause  irregularity  of  the  permanent 
teeth. 

For  most  cases  the  cement  should  be  mixed  as  thick  as  can  be  easily 
and  quickly  manipulated,  but  if  the  pulp  is  nearly  exposed  the  cement 
should  be  used  so  thin  that  it  can  be  applied  without  pressure,  by 
flowing  it  over  the  floor  of  the  cavity.  Cement  mixed  moderately 
thin  will  adhere  better  to  the  walls  of  the  cavity  than  when  it  is  as 
thick  as  it  is  possible  to  apply  it.  The  thinner  the  cement,  the  longer 
time  it  will  take  to  harden,  but  the  thicker  it  is  mixed  the  more  dur- 
able it  will  be.  Do  not  keep  the  little  patient  in  a  constrained  posi- 
tion longer  than  necessary.  The  easier  the  first  operation  is  for  him 
the  more  readily  will  he  return  for  the  second. 


FILLING  MATERIALS.  675 

If  the  pulp  is  very  nearly  exposed  apply  Fletcher's  carbolized  resin 
over  the  floor  of  the  cavity.  For  this  purpose  remove  the  stopper  of 
the  bottle  till  by  evaporation  the  carbolized  resin  has  thickened  to  the 
consistence  of  molasses.  Dip  a  small  probe  in  this  thickened  mass,  so 
that  a  small  drop  will  adhere  to  the  end.  This  drop  mav  be  then  con- 
veyed to  and  spread  over  the  floor  of  the  cavity.  This  will  prevent 
contact  of  the  cement  with  the  most  sensitive  dentin  and  lessen  the 
possibility  of  deleterious  action  on  the  pulp. 

Where  it  is  possible  to  apply  the  rubber  dam  and  excavate  thoroughly 
the  same  excellent  result  with  cement  may  be  expected  as  when  it  is 
used  in  permanent  teeth,  but  often  it  is  not  possible  to  operate  as 
thoroughly. 

By  applying  melted  paraffin  ^  or  sandarac  varnish  to  the  cement  the 
rubber  dam  may  be  removed  sooner  than  otherwise,  and  the  cement 
will  be  protected  from   moisture  by  the  coating  of  paraffin  or  varnish. 

As  paraffin  is  insoluble  in  any  agent  that  can  attack  it  in  the  mouth, 
the  more  it  is  absorljcd  by  the  cement  the  longer  it  will  protect  it  from 
everything  but  wear ;  therefore,  do  not  be  content  to  merely  flow  the 
melted  paraffin  over  the  cement,  but  hold  a  heated  instrument  in  contact 
with  the  filling  and  keep  the  paraffin  melted  until  all  that  is  possible  is 
absorbed.  If  an  approximal  filling  has  been  inserted  pass  a  very  thin 
heated  spatula  between  the  cement  filling  and  the  adjoining  tooth  to 
make  sure  that  the  paraffin  covers  it  to  its  cervical  margin. 

When  the  rubber  dam  cannot  be  applied,  cement  may  still  be  used 
with  success  if  the  cavity  can  be  kept  dry  with  napkins  or  rolls  of 
cotton  or  spunk  until  it  is  inserted  and  quickly  covered  with  melted 
paraffin. 

Deep  cavities  may  be  advantageously  lined  w  itli  cement  and  protected 
with  paraffin  till  the  cement  is  hard,  when  the  paraffin  mav  be  removed 
and  gutta-percha  or  amalgam  inserted. 

Cavities  ix  Incisors. — Decay  in  deciduous  incisors  is  much  more 
rare  than  in  the  other  teeth,  and  they  are  lost  so  early  in  child  life  that 
it  is  seldom  necessary  to  fill  them.  Zinc  phosphate  cement  is  the  best 
filling  material  for  these  teeth,  because  they  are  so  small  that  it  is  very 
difficult  to  shape  the  cavities  properly  for  retaining  other  materials. 

If  it  is  found  that  cement  disintegrates  rapidly  in  approximal  cavities, 
an  attempt  should  be  made  to  shape  them  so  as  to  retain  gutta-percha. 
The  first  filling  of  cement  may  have  removed  the  sensitiveness  suf- 
ficiently to  allow  deeper  excavating  at  a  subsequent  sitting,  or  there 
may  have  been  a  deposit  of  secondary  dentin,  thus  removing  the  pulp 
from  danger  of  exposure  in  properly  shaping  the  cavity. 

Amalgam. — While  amalgam  is  a  valuable  filling  material,  its  use 
'  Dr.  Bonwill's  suggestion. 


676  MANAGEMENT  OF  THE  DECIDUOUS  TEETH. 

necessitates  much  oreator  care  in  the  jji-cparation  of  cavities  than  is 
necessary  with  trutta-percha  or  cement,  for  it  iicitlicr  s|)rea<ls  under 
mastication  lii^e  the  former  nor  does  it  adhere  to  the  walls  of  a  cavity 
like  the  latter.  The  spreadin^y  of  ^utta-]iercha  will  stop  a  leak  that 
would  be  fatal  to  an  amalgam  filling,  and  cement  will  adhere  in  a  cav- 
ity from  which  amalgam  would  be  easily  dislodged. 

Amalgam  should  be  used  w^hen  the  decay  can  be  thoroughly  excava- 
ted and  the  cavity  prepared  with  strong  smooth  edges,  and  good  under- 
cuts or  retaining  grooves.  As  amalgam  is  a  better  conductor  of  thermal 
impulses  than  either  of  the  materials  before  mentioned  it  will  not  be 
tolerated  so  near  the  pulp,  hence  deep  cavities  must  be  lined  with  either 
gutta-percha  or  zinc  }>hosphate. 

The  large  size  of  the  pul[)  of  (hn-iduous  teeth — greater  in  proportion 
than  that  of  the  permanent  teeth — must  not  be  forgotten  in  exca- 
vating, and  often  it  is  impossible  to  make  suitable  retaining  grooves  for 
amalgam  without  cutting  dangerously  near  the  pulp,  es])ecially  in  ap- 
proximal  cavities. 

The  preparation  of  occlusal  cavities  is  comparatively  siui])le,  as  the 
enamel  may  be  easily  cut  away  so  as  to  make  firm  edges,  slightly 
bevelled,  and  to  allow  thorough  excavation  of  softened  dentin. 

The  burring  engine  can  be  used  to  greater  advantage  with  children 
than  many  would  suppose.  The  whirring  noise  often  distracts  their 
attention  from  a  slight  jxiin  they  might  otherwise  notice,  and  the  assur- 
ance that  the  work  can  be  done  more  cpiickly  is  a  great  encouragement. 
In  preparing  approximal  cavities  for  amalgam  a  free  opening  should 
be  made  in  the  occlusal  surface  and  given  a  dovetail  shape,  extending 
farther  upon  the  occlusal  surface  in  proportion  to  the  size  of  the  cavity 
than  in  permanent  teeth,  because  more  reliance  must  be  placed  on  it  for 
retention  than  upon  lateral  grooves,  for  there  is  not  much  depth  of 
dentin  in  which  to  make  them.  The  cervical  border  of  the  cavity  must 
be  smooth  and  the  floor  at  right  angles  to  the  long  axis  of  the  tooth. 
The  lateral  walls  must  be  cut  smooth  and  Ijevelled,  and  may  be 
slightly  grooved.  If  the  cavity  extends  below  the 
margin  of  the  gum  the  latter  should  be  crowded 
away  with  a  tem})orary  stopping  or  by  packing  a 
tightly  rolled  pledget  of  cotton  between  the  teeth 
and  relying  on  its  swelling. 

While  the  application  of  a  rubber  dam  is  not  as 
Prepared  cavity  showing     essential  as  in  using  cement,  it  is  a  great  advantage, 

beveUing    of    enamel       „       .^  i  ii  '  a-  r  ^u  v 

edges,  A,A,  and  square     for  it  renders  the  proper  preparation  ot  the  cavity 
base  for  fining,  B.  ^^^^e  certain,  but  it  need  not  be  applied  till  the 

cavity  is  nearly  prepared.     Its  use  is  more  often   necessary  with   the 

lower  teeth  than  with  the  upper. 


EXPOSED  PULPS.  677 

Amalgam  should  not  l)e  mixed  too  drv,  l)nt  should  be  plastic  enough 
to  be  packed  easily  Avithout  crumbling.  In  occlusal  cavities  introduce  a 
piece  half  as  large  as  the  cavity,  and  with  a  small  ball  l)urnisher  spread 
it  over  the  floor  of  the  cavity  toward  the  walls.  Introduce  other  smaller 
pieces  and  proceed  as  before  until  the  cavity  is  nearly  full.  Excess  of 
mercury  is  thus  forced  to  the  edges  of  the  cavity,  whence  it  can  be 
brushed  away  with  cotton  or  bibulous  paper. 

The  last  pieces  of  amalgam  should  be  "  wafered,"  as  recommended 
by  Prof.  J.  Foster  Flagg — that  is,  squeezed  in  chamois  skin  with  large 
flat-nosed  pliers  till  as  much  mercury  as  possible  is  pressed  out  (see 
Fig.  288).  This  leaves  the  amalgam  in  a  thin,  brittle  wafer,  too  hard 
for  ordinary  use.  Break  it  up  in  pieces  half  the  diameter  of  the  cavity. 
Press  one  of  these  in  the  middle  of  the  nearly  completed  tilling.  It 
will  readily  absorb  the  excess  of  mercury  that  has  been  worked  to  the 
surface,  and  can  be  spread  toward  the  margins  with  a  round  burnisher. 
Other  pieces  can  be  burnished  on  till  the  filling  is  quite  hard. 

In  filling  a})proximal  cavities  the  same  plan  may  be  followed  if  a 
matrix  of  thin  steel  or  German  silver  be  used.  In  lieu  of  the  matrix 
a  very  thin  spatula  may  be  held  between  the  teeth. 

Whenever  possible,  fillings  in  deciduous  molars  should  be  contoured 
to  avoid  the  crowding  of  food  between  the  teeth  and  also  to  prevent  the 
first  permanent  molar  from  crowding  them  together  and  thus  taking  up 
room  which  will  be  needed  by  the  bicuspids. 

The  child  should  be  cautioned  against  masticating  too  soon  upon 
approximal  fillings,  though  no  caution  is  needed  in  case  of  occlusal  fill- 
ings hardened  by  the  "  wafering  "  process. 

Tin  and  gold  are  excluded  from  the  list  of  desirable  filling  materials 
for  temporary  teeth,  not  because  they  are  not  good  filling  materials  but 
because  the  circumstances  are  such  that  they  cannot  l)e  used  to  advan- 
tage. Though  a  small  gold  filling  may  be  inserted  in  a  few  minutes  in 
an  occlusal  cavity,  the  insertion  of  a  large  gold  filling  would  be  inflict- 
ing a  needless  cruelty  on  a  child  on  account  of  the  length  of  time  it 
must  be  held  in  one  position. 

As  the  insertion  of  a  tin  filling  is  nearly  if  not  quite  as  difficult  and 
tedious  an  operation,  it  is  o])en  to  the  same  objection. 

Exposed  Pulps. 

On  account  of  the  difficulty  of  properly  capping  an  exposed  pulj)  in 
a  deciduous  tooth,  the  operation  should  seldom  be  attempted.  It  is 
better  to  devitalize  the  Jiulp  and  remove  it. 

The  writer  has  found  the  following  formula'  an  excellent  one: 

»  Used  bv  Dr.  E.  N.  Clarke  in  the  "fifties." 


678  MANAGEMENT  OF  THE  DECIDUOUS  TEETH. 

I^.  Acidi  arseniosi, 
MorphijB  acetatis, 
Piilv.  opii,  cid.  pars  ceq. 

Creosoti  q.  s.  to  make  paste. 

Why  opium  and  acetate  of  morpliia  should  both  he  used  in  the  same 
prescription  is  not  clear,  as  their  properties  are  so  nearly  the  same,  but 
the  ]xiste  has  been  satisfactory  in  devitalizing;  j)ulps  with  no  ])ain,  or 
with  a  minimum  amount.     Other  formulas  may  be  equally  satisfactory. 

In  occlusal  cavities  its  application  is  sim})le.  Excavate  the  softened" 
dentin  as  thoroughly  as  possible  without  inflicting  ])ain,  using  spoon- 
shaped  excavators  to  prevent  puncturing  the  pulp.  If  the  excavation 
can  be  carried  far  enough  to  apply  the  paste  directly  to  the  pulp  its 
action  will  be  more  rapid.  Dry  the  cavity,  apply  a  small  amount,  not 
larger  than  half  a  pinhead  in  size,  with  a  small  probe  and  cover  it  with 
a  pellet  of  cotton,  or  place  in  the  cavity  a  small  pellet  of  cotton  one 
side  of  Avdiich  has  been  touched  to  the  paste.  Add  enough  pellets  of 
dry  cotton  to  fill  the  cavity,  then  a])ply  a  drop  of  sandarac  varnish,  suf- 
ficient to  saturate  at  least  half  the  depth  of  cotton.  This  is  a  better 
plan  than  dipping  the  pellets  in  the  varnish  before  inserting,  because  an 
excess  of  the  latter  is  a])t  to  come  in  contact  with  the  pulp  and  cause 
pain,  or,  penetrating  between  the  paste  and  the  pulp,  may  render  the 
former  inoperative.  Temporary  stoppings  such  as  Gilbert's,  White's,  or 
Fowler's  are  excellent  for  sealing  the  cavity,  but  take  a  little  more 
time  than  cotton  and  varnish.  Such  temporary  stopping  should  be  well 
softened  by  heat  to  prevent  pressure  on  the  pulp  in  its  insertion.  A 
good  plan  is  to  warm  the  end  of  the  long  stick  of  stopping  and  press 
it  into  the  cavity,  using  the  remainder  of  the  stick  as  a  handle,  then 
remove  the  surplus  and  smooth  with  a  warm  instrument. 

In  approximal  cavities  extending  near  or  under  the  margin,  the  gum 
should  be  protected,  before  applying  the  paste,  as  follows  : 

Make,  by  rolling  between  the  fingers,  a  cylinder  of  cotton  as  long 
as  the  width  of  the  tooth  and  about  the  size  of  the  lead  of  a  pencil. 
Saturate  it  with  sandarac  varnish  and  pack  it  between  the  teeth  npon 
the  gum,  extending  part  of  it  below  the  edge  of  the  cavity,  thus  sealing 
this  portion  of  the  cavity  and  reducing  it  nearly  to  the  form  of  an 
occlusal  cavity.  Paste  applied  in  an  approximal  cavity  so  protected 
cannot  flow  upon  the  gum  unless  too  great  a  quantity  has  been  used. 
The  paste  should  be  applied  and  sealed  as  in  an  occlusal  cavity. 

"  Devitalizing  fiber  "  is  very  satisfactory  and  may  be  used  with  less 
fear  of  its  affecting  the  gum  tissue. 

The  paste  may  be  allowed  to  remain  in  the  cavity  for  from  twelve 
to  forty-eight  hours.     The  possibility  of  the  dressing  being  dislodged,  so 


FILLING   PULP  CANALS.  679 

as  to  allow  the  paste  to  come  in  contact  with  the  o;nm  tissue,  should 

■  warn  one  to  have  the  patient  return  much  sooner  than  wlien  the  case 

is  an  occlusal  cavity  from  which  it  is  impossible  for  the  paste  to  escape. 

]\[uch  has  been  said  about  the  danger  of  application  of  arsenic  in 
deciduous  teeth  when  the  roots  are  undergoing  resorption,  but  the 
writer  has  never  seen  any  bad  effects  from  such  use  ;  still  it  must  be 
admitted  that  the  ratio  of  danger  varies  with  the  degree  of  resorption 
of  the  root.  An  examination  of  Prof.  Peirce's  diagram  (Fig.  593)  will 
show  the  average  amount  of  resorption  at  different  ages,  and  enable 
one  to  discriminate.  The  writer  believes  that  the  sensitiveness  of  a 
deciduous  pulp  varies  inversely  M'ith  the  amount  of  resorption  of  the 
root,  and  that  devitalization  is  called  for  in  very  few  cases  in  which 
there  is  danger  of  deleterious  action. 

Prof.  L.  L.  Dunbar  advises  the  use  of  aqua  ammonias  for  devitaliz- 
ing the  pnlp  of  a  temporary  tooth,  by  applying  it  on  a  })ledget  of  cotton 
in  the  cavity,  one  or  two  applications  being  sufficient  in  most  cases. 
This  plan  is  not  open  to  the  objections  urged  against  the  use  of  arsenous 
oxid. 

When  the  pulp  is  devitalized,  open  the  cavity  freely  into  the  pulp 
chamber  and  apply  on  cotton  a  solution  of  tannic  acid  in  glycerol. 
Leave  this  about  a  week,  by  which  time  the  pulp  tissue  will  have  be- 
come so  hardened  by  the  tannin  that  it  may  be  removed  much  more 
readily  than  Avithout  such  treatment. 

The  application  of  mummifying  paste  is  advised  by  many,  after 
devitalization,  to  avoid  the  necessity  of  removing  the  pulp.  If  a  real 
mummifying  paste  can  be  found,  its  application  will  be  the  ideal 
treatment. 

Pilling  Pulp  Canals. 

In  the  pulp  canals  apply  iodoform  paste  made  by  mixing  iodoform 
and  glycerol  to  such  a  consistence  that  it  can  be  readily  ajiplied  on  a 
probe. 

Fill  the  pulp  chamber  with  "  temporary  stopping  "  or  gutta-percha, 
and  the  cavity  with  cement,  gutta-percha,  or  amalgam  according  to 
indications. 

If  the  tooth  be  very  frail,  fill  the  cavity  with  cement,  because,  owing 
to  its  adhesive  properties,  it  strengthens  the  tooth.  If  the  cavity  be 
approximal  and  it  is  desirable  to  wedge  the  teeth  apart,  use  pink  gutta- 
percha. 

If  the  walls  be  strong  and  some  time  will  elapse  before  the  natural 
exfoliation  of  the  tooth  will  occur,  fill  with  amalgam. 

If  absorption  of  the  roots  occurs,  the  iodoform  in  the  canals  will  not 
interfere. 


680  MANAGEMENT  OF  THE  DECIDUOUS  TEETH. 

Salol,  whicli  was  advocated  as  a  root  filliiijir  for  permanent  teeth  by 
Dr.  A.  E.  Mascort^  of  Paris,  France,  is  well  adapted  also  for  fillino;  the 
canals  of  deciduous  teeth,  "  It  is  a  white  crystalline  powder,  insoluble 
in  water  and  glycerol,  but  soluble  in  alcohol,  ether,  chloroform,  etc. ; 
fuses  at  40°  C.  but  crystallizes  quickly  again."  Melted  together,  salol 
and  aristol,  salol  and  iodoform,  or  salol  and  paraffin,  become  liquid 
like  salol  alone.  After  a  pulp  canal  is  thoroughly  dried  the  salol  may 
be  fused  on  a  small  spatula  and  carried  to  the  canal,  into  which  it  wiir 
be  taken  by  capillary  attraction  or  a  broach  may  be  heated  and  inserted 
in  the  salol.  A  small  (juantity  will  adhere  like  a  drop  of  liquid  and 
may  thus  be  carried  to  the  canal.  The  heated  broach  may  be  again 
introduced  in  the  canal  to  insure  thorough  apj)lication.  Dr.  Mascort 
uses  the  hypodermic  syringe  Avith  a  small  needle  for  introducing  into 
the  canals.  It  will  crystallize  in  a  very  short  time,  making  a  solid  fill- 
ing. Though  the  writer  has  not  had  much  experience  with  salol  as  a 
root  filling,  he  is  so  far  well  pleased  with  the  result.  (See  Chapter 
XVII.,  p.  439.) 

Alveolar    Abscess. 

The  treatment  should  be  the  same  as  with  the  permanent  teeth,  that 
is,  removal  of  the  cause — which  is,  almost  invariably,  a  decomposed 
pulp.  Even  with  a  decomposed  pulp  an  abscess  seldom  occurs  if  there 
be  any  opening  from  the  cavity  of  decay  to  the  l)ulp  chamber,  unless 
such  opening  has  become  stopped  by  some  foreign  substance. 

Make  a  free  opening  into  the  pulp  chamber  and  Avith  a  syringe 
Avash  out  as  much  of  the  contents  as  possible.  Dry  the  chamber  and 
Avith  a  "  minim  "  syringe  (see  Chapter  XVII. ,  Fig.  441),  or  drop  tube, 
apply  hydrogen  dioxid.  While  capillary  attraction  will  carry  this 
into  a  dry  canal,  the  application  of  a  nerve  broach,  preferably  platino- 
iridium,  will  serve  to  mix  it  thoroughly  Avith  the  contents  of  other 
canals,  and  increase  its  efficiency. 

If  a  fistulous  opening  has  formed  through  the  outer  alveolar  plate 
but  not  through  the  gum,  an  opening  should  be  made  through  the  latter 
with  a  sharp  lancet  about  five  minutes  after  the  application  of  4  per 
cent,  cocain  hydrochlorid  solution  on  a  Avad  of  cotton. 

If  hydrogen  dioxid  can  be  forced  from  the  pulp  chamber  through 
the  root  canals  and  fistulous  opening,  the  accumulated  pus  Avill  be 
thoroughly  evacuated  and  the  cure  hastened.  As  a  rule,  hoAvever,  the 
abscess  disappears  after  the  cause  is  remoA^ed,  that  is,  the  jjutrescent  or 
decomposed  contents  of  the  pulp  chamber  and  canals. 

After  drying  the   pulp  chamber  and  canals,  apply  iodoform   paste 

1  Dental  Cosmos,  1894,  p.  352. 


PROPHYLACTIC  TREATMENT.  681 

therein  and  seal  the  cavity  for  a  few  days  with  temporary  stopping. 
When  the  inflammation  of  the  pericementnm  has  disap])eared  the  pnlp 
chamber  and  canals  may  be  filled  as  before  directed. 

In  many  cases  the  inflammation  of  the  pericementnm  will  be  so 
great,  or  in  popular  expression  the  tooth  so  "  sore "  to  the  touch, 
when  the  case  is  presented  that  at  the  first  sitting  nothing  more  can  be 
done  than  to  make  an  opening  into  the  pulp  chamber  to  allow  the  escape 
of  pus  or  gases  of  decomposition.  By  this  means  the  pain  will  be  re- 
lieved and  the  rest  of  the  manipulation  and  treatment  may  be  left  till 
the  inflammation  has  subsided. 


Prophylactic  Treatment. 

This  lies  more  in  the  hands  of  the  parent  than  of  the  practitioner, 
but  should  be  strongly  urged  by  the  latter  upon  the  former.  The  nurse 
or  parent  should  begin  early  to  clean  the  child's  teeth  by  means  of  a 
cloth  wrapped  around  the  finger.  If  the  teeth  cannot  be  kept  clean  in 
this  manner  a  small  brush  should  be  used,  especially  after  eruption  of 
the  molars.  Floss  silk  should  be  used  daily  between  the  teeth.  One 
end  of  the  silk  should  be  held  in  each  hand  in  such  a  manner  as  to  pass 
over  the  end  of  each  index  finger  and  be  made  taut  between  them. 
This  taut  part  can  be  pressed  down  betAveen  the  teeth  and  passed  up  and 
down  against  the  approximal  surface  of  each  tooth,  then  one  end  of  the 
thread  should  be  released  from  one  hand  and  pulled  through  the 
interdental  space  with  the  other. 

This  will  drag  out  any  particles  of  food  that  may  be  there,  and  is 
much  better  than  the  toothpick  for  the  purpose.  If  particles  of 
meat  or  other  food  have  lodged  so  firmly  that  the  plain  waxed  silk 
will  not  dislodge  them,  tie  a  single  knot  in  the  thread  and  pull  that 
through. 

This  cleansing  with  tlie  clotli,  brush,  and  silk  should  be  done  before 
the  child  retires  at  night,  for  that  is  tlie  "  period  of  decay."  The  parts 
are  at  rest  longer  than  at  any  other  time,  and  the  fluids  of  the  mouth 
are  not  kept  in  circulation  between  the  teeth  by  means  of  the  tongue, 
lips,  and  cheeks.  Theoretically  the  teeth  should  be  thus  thoroughly 
cleaned  after  each  meal,  but  "  satiety  breeds  disgust,"  and  it  is  not 
best  to  insist  on  more  than  will  probably  be  accomplished. 

Children  will  soon  learn  to  use  the  brush  and  floss  silk  themselves, 
and  finding  the  mouth  much  more  comfortable  when  "  clean  "  they  will 
endeavor  to  keep  it  so.  Many  a  child  has  been  denied  candy  for  years 
from  the  belief  that  "  sweets  decay  the  teeth,"  but  parents  may  be  as- 
sured that  no  harm  will  be  done  if  the  "sweet"  is  not  allowed  to 
remain   between   and   around  the  teeth  till  it  becomes  acid,  and  that 


682  MANAGEMENT  OF  THE  DECIDUOUS  TEETH. 

may  be  prevented  by  cleansing  the  teeth  after  the  candy  or  sugar  is 
eaten.  A  child  may  be  taught  cleanliness  in  this  manner  who  would 
be  only  taught  rebellion  by  the  repeated  denial  of  sweets,  the  reason  of 
which  he  cannot  understand. 

Pro})hylactic  mouth-washes  should  be  used — such  as  listerine  diluted 
to  a  10  per  cent,  solution. 


CHAPTER  XXIV. 

ORTHODONTIA  EXCLUSIVELY  AS   AN    OPERATIVE 
PROCEDURE. 

By  Claek  L.  Goddard,  A.  M.,  D.  D.  S. 


The  Normal  Arch. — As  the  study  of  physiology  is  necessary  before 
the  study  of  pathology,  so  is  a  study  of  the  normal  arrangement  of  the 
teeth  necessary  before  the  treatment  of  their  irregularities  should  be 
undertaken. 

The  ideal  facial  profile  is  shown  in  Fig.  598.     The  face  from  the 

Fig.  598. 


\ 

The  facial  profile. 

hair  to  the  chin  measures  three-fourths  of  the  whole  height  of  the  head. 
The  forehead  to  the  root  of  the  nose  measures  one-fourth,  the  nose  one- 
fourth  and  the  mouth  and  chin  one-fourth.  The  distance  vertically 
from  the  root  of  the  nose  to  its  lower  border  is  equal  to  the  distance 
from  this  point  to  the  bottom  of  the  chin.  Of  this  latter  distance  one- 
half  is  occupied  by  the  lips  and  one-half  by  the  chin.  The  nose,  then, 
equals  in  length  the  lips  and  chin. 

683 


084 


ORTironoXTfA    AS  AN  OPERATIVE  PROCEDURE. 


The  u|)|)(M'  (Icntnl  arcli  is  sliown  in  Fio;.  599.     The  six  anterior  teeth 
are  arranged  in  tlie  segment  of  a  circle.     The   l)iciis|)i(ls  and  molars 

Fig.   599. 

jiipitiiiiiiiiiiiiiiii*'!;  . 


Normal  upper  dental  arch. 

form  almost  straight  diverging  lines  from  the  canines,  though  the  posi- 
tion of  the  third  molar  is  somewhat  outside  of  that  line. 

The  normal  occlusion  of  the   teeth  is  shown  in  Fig.  600.     The 
six  upper  anterior  teeth  close  over  the  six  lower  ihmi  a  third  to  a  half 

Fig.  600. 


\T^' 


Normal  occlusion. 


of  the  length  of  the  latter.  The  lower  second  bicuspid  occludes  between 
the  cusps  of  the  two  upper  bicuspids  and  is  the  hey  to  the  occlusion; 
this  is  a  point  easily  remembered.  Each  bicuspid  and  molar  of  each 
jaw,  excepting  the   upper  third  molar,  is  antagonized  by  two  of  the 


DISTAL   OCCLUSION. 


685 


teeth  of  the  opposite  jaw.  The  buccal  cusps  of  the  lower  teeth  close 
between  the  buccal  and  lingual  of  the  upper,  and  the  lingual  cusps  of 
the  upper  close  between  the  lingual  and  buccal  cusps  of  the  lower. 

As  the  lower  jaw  moves  laterally  during  mastication  the  cusps  of  the 
bicuspids  and  molars  grind  upon  each  other,  while  the  six  anterior  teeth, 
overlapping  but  not  touching,  pass  bv  each  other  and  escape  wear.  In 
order  to  touch  the  cutting  edges  of  the  upper  and  lower  incisors  upon 
each  other  the  lower  jaw  is  protruded,  and  at  such  a  time  the  masticat- 
ing teeth  do  not  occlude. 

Mal-occlusion  may  be  of  many  kinds  and  degrees,  to  which  no 
general  description  can  be  given.  The  eruption  of  a  single  tooth 
labially  or  lingually  or  turned  on  its  axis  may  disarrange  the  occlusion 
of  all  the  neighboring  teeth  or  even  all  the  teeth  of  both  arches.  Like- 
wise the  loss  of  a  single  permanent  tooth  or  its  failure  to  erupt  may 
have  a  more  disastrous  etfect. 

There  are  many  cases,  however,  in  which  both  arches  are  normal, 
yet  their  relation  to  each  other  is  such  that  it  results  in  mal-occlusion. 

Tlie  nature  of  such  mal-occlusion  of  the  arches  as  a  whole  mav  be 
indicated  by  the   position  of  the   second   lower  bicuspid,    which  is  the 


Fig.  601. 


Distal  occlusion  of  the  jaws. 

key  to  the  occlusion  ;  according  to  its  position,  the  occlusion  of  the 
arches  may  be  described  as  normal,  distal,  mesial,  lingual,  or  buccal. 

If  the  key  tooth,  the  second  lower  bicuspid,  closes  between  the 
upper  bicuspids,  with  its  buccal  cusp  between  their  buccal  and  lingual 
cusps,  the  occlusion,  both  of  the  kev  tooth  and  all  the  others,  is  normal 
(Fig.  600). 

Distal  Occlusion. — If  the  key  tooth  closes  posteriorly  or  back  of 
the  normal  position  to  any  degree,  even  to  the  width  of  a  bicuspid  or 
more,  the  occlusion  is  distal,  as  shown  in  Figs.  601  and  603.  This 
mal-occlusion  may  be  on  one  or  both  sides  of  the  mouth.  It  may  be 
due  to  lack  of  development  of  the  lower  maxilla,  or  the  fault  may  be 
in  the  temporo-maxillary  articulation. 


686 


ORTHODONTIA  AS  AN   OPERATIVE  PROCEDURE. 


An  upper  protrusion  may  be  described  as  a  distal  occlusiou  of  the 
lower  jaw  on  both  sides  (or  a  bilateral   distal  occlusiou). 

Mesial  Occlusion. — If  the  key  tooth  closes  anteriorly  or  uiesially 
to  the  normal  position  to  any  degree,  even  to  the  width  of  a  bicuspid 
or  more,  the  occlusion  of  the  jaws  is  shown  to  be  mesial  (Fig.  602). 
This  may  occur  on  one  or  both  sides  of  the  mouth  and  may  be  the  fault 
of  the  teeth  themselves,  if  the  abnormality  is  slight.  It  may  be  due 
to  lack  of  development  of  the  upper  maxilla,  as  in  Fig.  779  ;  or  abnor- 
mal  development  of  the  lower   maxilla,  as  shown  in   Fig.  780,  both 

Fig.  002. 


^^^^ 

jl        ^ 

■  ^                             .-             :=^- 

^^  w^ 

J 

^Li^fa,    X. 

ji 

ll 

Mesial  occlusion  of  the  jaws  (also  buccal  occlusion  and  mesio-buccal  occlusion). 

being  cases  of  lower  protrusion.  Hence  lower  protrusion  may  be  de- 
scribed as  mesial  occlusion  of  the  lower  jaw  (or  lower  maxilla). 

Buccal  Occlusion. — If  the  lower  arch  is  wider  than  the  upper,  so 
that  the  buccal  cusps  of  the  lower  bicuspids  and  molars  do  not  close 
between  the  buccal  and  lingual  cusps  of  the  upper  teeth,  but  close 
outside  in  any  degree,  even  to  the  width  of  a  cusp  or  more,  the  key 
will  be  found  in  a  buccal  position,  and  the  whole  occlusion  is  buccal, 
as  shown  in  Figs.  602  and  781. 

This  may  occur  on  one  or  both  sides  of  the  arch  (unilateral  or 
bilateral),  and  may  be  due  to  a  narrow  upper  arch  or  a  wide  lower 
arch. 

Lingual  Occlusion. — If  the  lower  arch  is  so  narrow  that  the  buc- 
cal and  lingual  cusps  of  the  lower  bicuspids  do  not  close  between  the 
buccal  and  lingual  cusps  of  the  upper  teeth,  but  close  inside  or 
toward  the  median  line  of  the  mouth  to  any  degree,  the  key  tooth 
will  be  found  in  a  lingual  position  and  the  whole  occlusion  is  lingual 
(Fig.  807). 

This  may  be  due  to  a  slight  disarrangement  of  the  teeth  themselves, 
or  to  abnormal  development  of  the  upper  or  lack  of  development  of 
the  lower  maxilla. 

Lingual  occlusion  may  occur  on  one  or  both  sides  of  the  arch  (uni- 
lateral or  bilateral),  or  there  may  be  lingual  occlusion  on  one  side  and 
buccal  occlusion  on  the  other. 


LABIAL  ASPECT. 


687 


In  cases  of  bilateral  mal-occlusion  either  buccal  or  lingual  expansion 
of  the  lower  or  upper  arch  is  indicated. 

Two  of  these  positions  may  occur  at  once  while  the  single  arches 
themselves  are  comparatively  normal. 

A  disto-lingual  occlusion  is  shown  in  Figs.  603  and  807. 

A  mesio-buccal  occlusion  is  shown  in  Figs.  602,  780,  and  781. 


Fig.  603. 


Disto-lingual  occlusion  of  the  jaws. 


Labial  Aspect. — In  examining  the  upper  six  anterior  teeth  from 
the  labial  aspect  (Fig.  604)  it  will  be  seen  that  they  touch  each  othei- 
at  one  point  only,  about  one-fourth 


of  the  distance  from  the  cutting  edge 


Fig.  604. 


The  six  auteriur  upper  teeth. 


to  the  gum  ;  also  that  the  long  axes 
of  the  teeth  are  not  parallel,  ])ut  the 
crowns  slant  toward  the  median  line. 
Of  the  six  upper  anterior  teeth  the 
central  incisors  are  the  longest,  the 
laterals  next,  and  the  canines  short- 
est, though  popularly  the  canine  is 
thought  to  be  the  lono-est  ttwth  be- 

cause  of  its  prominence  and  the  length  of  its  cusps.  It  will  be 
noticed  that  the  gum  line  is  higher  on  the  canine,  thus  addi ug  to  its 
apparent  length. 

A  line  connecting  the  cutting  edges  and  cusps  of  half  the  upper 
teeth  forms  a  double  curve,  highest  at  the  third  molar  and  lowest  at  the 
central  incisor,  the  line  of  beauty,  while  such  a  line  on  the  lower  teeth 
forms  but  one  curve,  highest  at  its  ends. 

While  the  aim  of  the  student  of  orthodontia  will  be  to  correct  all 
irregularities  and  reduce  the  abnormal  to  the  normal,  it  will  be  possible 
in  many  cases  to  do  this  only  in  degree.  The  normal  may  always  be 
approached,  but  not  always  attained. 


G88 


ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 

Order  of  Eruption  of  Permanent  Teeth} 
1.  Central  Incisors — from     6th  to    8th  year. 


2. 

T.aternl       '' 

7th  " 

9th 

3. 

Lower  Canines 

8  th  " 

10th 

4. 

First  Bicnspids 

9th  " 

10th 

5. 

Second       " 

10th  '' 

12th 

6. 

Ui)per  Canines 

11th  " 

12th 

7. 

First  Molars 

5th  " 

6th 

8. 

Second       " 

12th  '' 

14th 

9. 

Third 

17th  " 

25th 

Wliile  most  tables  place  the  eruption  of  all  the  canines  after  that 
of  the  bicuspids,  it  will  be  noticed  that  in  this  the  lower  canine  pre- 
cedes and  the  upper  canine  follows  both  bicuspids. 

The  lateral  incisor  fails  to  erupt  more  often  than  any  tooth  except 
the  third  molar.  It  also  erupts  out  of  line  more  often  than  any  tooth 
except  the  canine. 

Fig.  605. 


Upper  and  lower  casts  showing  in  the  same  moutli  tlie  two  irregularities  mentioned  on  page  089. 


The  lateral  incisor  is  duplicated  more  often   than  any  other  tooth, 
cases  of  five  or  six  incisors  sometimes  arranged  in  the  normal  curve 
^  Farrar,  Treatment  of  Irregularities  of  the  Teeth,  vol.  i.  p.  483. 


THE  DECIDUOUS  TEETH. 


689 


of  the  arch,  but  more  often  crowded  out  of  Hue,  being  seen  occasionally. 
This  is  evidently  a  reversion  to  the  six  incisors  of  the  normal  mam- 
malian formula : 


^3-3     1-1  ^      4-4  ,^3-3 
I3I3  ^1=1  P»^  4-1  ^  3-3 


44. 


Occasionally  a  bicuspid  (premolar)  is  duplicated,  a  reversion  to  the 
before-mentioued  type,  in  which  four  premolars  are  normal. 

The  dilFerence  in  the  order  of  eruption  of  the  upper  and  lower  canines 
has  an  effect  upon  the  position  of  those  teeth.  The  upper  canine  erupts 
out  of  line  more  often  than  the  lower,  while  irregularity  of  the  lower 
bicuspids  is  more  frequent  than  of  the  upper.  In  each  case,  being  the 
last  of  the  successional  teeth  to  erupt,  there  is  often  insufficient  room  to 
enable  them  to  assume  their  normal  positions.     (See  Fig.  605.) 


The  Deciduous  Teeth. 

The  position  of  the  deciduous  teeth  is  almost  always  normal.     One 
or  two  teeth  may  be  misplaced,  either  by  an  inherited  tendency  or  by 


Fig.  60f). 


Upper  and  lower  jaws  of  a  child  aged  about  six  and  a  half  years,  showinp;  portions  of  the 
developing  permanent  teeth  and  the  roots  of  the  deciduous  teeth. 

pernicious  habits,  such  as  sucking  the  thumb.  The  irregularity,  how- 
ever, is  so  slight  and  so  infrequent,  and  the  deciduous  teeth  are  retained 
in  the  mouth  for  so  short  a  time,  that  there  is  no  occasion  for  treatment. 
A  regular  arch  of  the  deciduous  teeth  does  not,  however,  foretell  a 
regular  arch  of  the  permanent  teeth.  Fig.  606  will  make  evident  that 
the  crowns  of  the  permanent  incisors,  canines,  and  bicuspids  are  formed 
44 


690  ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 

ill  the  jaw  before  the  roots  of  the  decicluoiis  teeth  are  absorbed.  From 
want  of  space  they  are  crowded  together,  and  already  present  all  phases 
of  irregularity. 

The  late  Prof.  J.  H.  M'Mullen  said  of  such  cases  :  "  When  we  are 
examining  a  series  of  jaws  of  different  ages,  arranged  so  as  to  show 
deciduous  and  permanent  teeth,  it  is  not  a  surprisiug  matter  that  there 
should  be  irregularity  in  the  permanent  set;  but  when  observing  their 
crowded  and  irregular  arrangement  in  the  jaw  ])rior  to  eru])tion,  it  is 
rather  a  matter  of  astonishment  that  they  should  ever  assume  a  regular 
symmetrical  appearance." 

As  the  permanent  teeth  are  larger  than  the  deciduous,  the  question 
naturally  arises,  How  is  room  provided  for  them  ? 

This  may  be  answered,  first,  by  dividing  the  permanent  teeth  into 
two  classes  :  those  which  replace  the  deciduous  teeth  and  those  which 
do  not.  For  the  first  class — that  is,  the  incisors,  canines,  and  bicuspids — 
room  is  made  by  interstitial  growth  and  by  the  fact  that  the  biscuspids 
are  smaller  than  the  deciduous  molars  which  they  replace.  For  the 
permanent  molars  room  is  made  by  growth  of  the  posterior  portion  of 
the  jaw. 

Etiology  of  Dental  Irregularities. 

^he  causes  of  irregularities  of  the  teeth  may  be  divided  into  three 
classes — hereditary,  constitutional,  and  acquired. 

As  children  inherit  other  peculiarities  of  structure  from  father, 
mother,  grandparent,  or  even  from  more  remote  ancestors,  so  may  irreg- 
ularities of  the  teeth  be  inherited.  The  causes  are  operative  before  the 
birth  of  the  child. 

Hereditary  causes  may  be  divided  into  two :  (a)  Direct,  in  which  a 
child  inherits  some  distinct  irregularity  just  as  he  may  inherit  some 
other  distinctive  feature.  (6)  Indirect,  in  which  he  inherits  separate 
peculiarities  which  combined  will  cause  an  irregularity.  For  example, 
large  teeth  may  be  inherited  from  one  parent  and  small  jaws  from  the 
other,  and  thus  Avill  be  produced  an  irregularity  of  some  kind,  but  not 
inherited  directly  from  either.  A  child  may  inherit  tone  of  voice, 
peculiar  gait,  or  other  habit ;  so  he  may  inherit  a  habit  which  will  cause 
an  irregularity.  The  intermarriage  of  different  races  is  a  prolific  cause 
of  irregularities  of  indirect  heredity. 

Dr.  Talbot^  defines  as  constitutional  irregularities  "those  that 
develop  w^ith  the  osseous  system,"  such  as  those  due  to  excessive  devel- 
opment or  to  lack  of  development  of  either  the  upper  maxillary,  inter- 
maxillary, or  lower  maxillary  bones,  or  of  the  ramus  or  body  of  the 
latter ;  too  high  vault,  too  narrow  vault,  etc. 

1  Etiology  af  Osseous  Deformities  of  Head,  Jaus,  and  Face,  3d  ed.  p.  16. 


ETIOLOGY  OF  DENTAL  IRREGULARITIES. 


691 


A  constitutional  irregularity  may  be  hereditary  or  may  be  due  to 
some  cause  affecting  the  osseous  system,  such  as  lack  of  development 
of  the  bones  about  the  nasal  cavity  from  lack  of  circulation  of  air 
through  this  cavity  and  connecting  sinuses,  due  to  mouth-breathing. 
The  result  may  be  a  high  vault  with  a  small  and  narrow  arch,  and 
consequent  crowding  and  various  irregularities  of  the  teeth. 

An  acquired  irregularity  may  be  due  to — 

(a)  Too  long  retention  of  deciduous  teeth. 

(6)  Too  early  extraction  or  loss  of  deciduous  teeth. 

(c)  Injudicious  extraction  or  early  loss  of  permanent  teeth. 

(d)  Delayed  eruption  of  permanent  teeth. 

(e)  Pernicious  habits  (thumb-sucking,  etc.). 

(/)  The  presence  of  supernumerary  teeth,  etc.     (See  page  697.) 


Lingual  eruption  of  permanent  incisors  due  to  too  long  retention  of  deciduous  incisors. 

Too  long  retention  of  deciduous  incisors  may  cause  lingual  eruption 
of  permanent  incisors  (see  Fig.  607)  or  rotation  of  the  same. 

Too  long  retention  of  deciduous  canines  may  cause  either  lingual 
eruption  (Fig.  700)  or  labial  eruption  of  permanent  canines  (608). 

Too  long  retention  of  deciduous  molars  may  cause  a  constricted  arch 
(Figs.  609  and  610;  also  page  785). 

(«)  Long  Retention  of  Deciduous  Teeth. — A  tooth  may  be  deflected 
from  its  normal  position  in  erupting  by  the  presence  of  a  supernumerary 
or  deciduous  tooth  the  root  of  which  has  not  been  absorbed.  Death  of 
the  l)ulp  t>f  a  deciduous  tooth  will  prevent  its  normal  or  physiological 
resorption.  It  may  then  be  removed  by  a  pathological  process  Mhich 
is  much  slower,  or  it  may  not  be  removed  at  all,  but  remain  indefinitely, 
or  till  removed  by  the  forceps. 

(6)  Too  Early  Extraction  of  Deciduous  Teeth, — As  Nature  pro- 
vides for  the  shedding  of  the  deciduous  teeth  at  the  proper  time,  inter- 
ference by  extraction  should  be  avoided  in  all  possible  cases. 

Unless  the  deciduous  teeth  are  retained,  the  natural  expansion  of  the 


692  ORTHODONTIA  AS  AN  OPERATIVE  PROCEDURE, 

Fk;.  008. 


Labial  eruption  of  permanent  canines  due  to  too  long  retention  of  deciduous  canines. 

FiCi.  609. 


Figs.  609  and  610:  Semi-constricted  arch  due  to  too  long  retention  of  deciduous  molars. 


ETIOLOGY  OF  DENTAL  IRREGULARITIES.  693 

jaw  by  interstitial  growth  will  be  interrupted.  When  a  deciduous  tooth 
is  extracted,  the  contiguous  teeth,  whether  deciduous  or  permanent, 
tend  to  move  toward  eacli  other  and  occupy  the  space  which  should  be 
preserved  for  the  succeeding  tooth. 

But  one  rule  is  needed,  as  follows  :  Extract  a  deciduous  tooth  only 
when   it  defects  its  successor. 

Rules  against  Extraction  of  Deciduous  Teeth. — 1.  Do  not 
extract  a  deciduous  latercd  to  make  room  for  a  permanent  central  incisor. 

2.  Do  not  extract  a  deciduous  canine  to  make  room  for  a  permanent 
lateral  incisor. 

Requests  for  such  extraction  will  often  be  made  by  the  parent,  to 
whom  the  explanation  should  be  made  that  such  extraction  is  liable  to 
prevent  the  natural  growth  of  the  jaw  for  the  accommodation  of  the 
permanent  teeth  ;  also  that,  while  the  six  anterior  deciduous  teeth  are 
replaced  by  larger  permanent  ones,  the  four  temporary  molars  in  each 
jaw  are  replaced  by  the  smaller  bicuspids,  and  that  when  this  takes 
place,  irregularities  of  the  incisors,  especially  the  lower  ones,  will  cor- 
rect themselves,  unless  the  teeth  are  too  large  for  the  jaw,  which  cannot 
be  foretold  with  certainty  at  this  age.  Even  if  it  could,  no  extraction 
of  deciduous  teeth  would  be  of  benefit,  but  rather  positive  harm. 

3.  Do  not  extract  a  deciduous  second  molar  till  the  first  permanent 
molar  is  firmly  fixed  in  place,  and  not  then  unless  the  second  bicuspid 
has  erupted  or  is  about  to  erupt  out  of  position. 

Requests  for  extraction  of  deciduous  molars  are  made  on  account 
of  cavities  of  decay,  which  should  be  filled  and  the  teeth  preserved  for 
service  in  mastication. 

The  only  exception  to  these  rules  is  in  cases  of  incurable  alveolar 
abscess,  which  may  endanger  the  alveolar  border  and  the  tooth  forming 
beneath. 

(e)  Early  Loss  of  Permanent  Teeth. — Irregularities  may  be  due 
also  to  early  loss  or  injudicious  extraction  of  permanent  teeth. 

An  early  loss  of  first  permanent  molars  may  cause  upper  or  lower 
protrusion. 

An  early  loss  of  lateral  incisors  causes  a  narrowing  of  the  anterior 
portion  of  the  arch  and  deprives  the  angles  of  the  mouth  of  their 
proper  contour. 

A  loss  of  canines  causes  a  depression  of  the  angles  of  the  mouth  and 
wins:  of  the  nose. 

(d)  Delayed  Eruption  of  Permanent  Teeth. — The  delayed  eruption 
of  anv  permanent  tooth,  after  the  loss  of  its  deciduous  predecessor,  will 
allow  the  teeth  on  each  side  of  the  s})ace  to  move  toward  each  other  and 
thus  prevent  eruption,  or  crowd  the  erupting  tooth  out  of  the  line  either 
labiallv  or  linguallv. 


694 


ORTHODONTIA  AS  AN  OPERATIVE  PROCEDURE. 


It  is  often  of  the  utmost  importance  to  ascertain  whether  a  tooth  is 
delayed  in  eruption  or  is  permanently  absent.  The  tooth  most  likely 
to  be  absent  is  the  third  molar.  The  one  next  most  likely  to  be  absent 
is  the  lateral  incisor,  generally  referred  to  as  the  "  missing  lateral." 

In  case  the  permanent  laterals  do  not  erupt  at  the  proper  time,  the 
question  often  arises  with  a  crowded  arch,  whether  to  preserve  space 
for  them  in  hopes  of  their  eruption,  or  to  allow  the  other  teeth  to  crowd 
along  and  occupy  the  space.  Hitherto  it  was  impossible  to  answer  this 
question,  but  lately  science  has  come  to  our  aid,  and  by  the  skiagraph 
the  uncertainty  can  be  made  a  certainty. 


Fig.  611. 


Fig.  612. 


Figs.  611-614,  and  the  following  description '  by  Dr.  J.  N.  :M'Dowell, 
will  illustrate  the  subject  of  delayed  eruption  : 


Fio.  61.3. 


Fig.  614. 


"Fig.  611  shows  the  models  of  a  boy  eight  years  old.  The  space 
for  the  laterals  is  entirely  closed  up.  The  teeth  in  both  the  upper 
and  lower  arches  were  regulated,  making  the  necessary  room  for  the 
laterals  in  the  upper  arch  (see  Fig.  612).  This  space  was  retained  for 
two  years,  and  at  the  end  of  that  time  there  was  still  no  sign  of  the 

1  Dr.  J.  N.  M'Dowell,  Dental  Cosmos,  March  1900,  vol.  xlii.  p.  237. 


ETIOLOGY  OF  DENTAL  IRREGULARITIES. 


695 


laterals.  Examination  gave  no  indication  of  delayed  teeth,  but  the 
result  of  the  .r-rav  (Fig.  613)  showed  the  laterals  high  up  in  the 
process  still  only  partly  developed.  It  was  several  months  later 
before  there  were  any  indications  of  the  laterals  making  their  appear- 
ance. Fig.  614  shows  the  same  case  eight  months  after  the  a:-ray  was 
taken." 

Oftentimes  the  occlusion  is  sadly  impaired  by  the  non-eruption  of 
a  bicuspid  impacted  between  contiguous  teeth.  The  skiagraph  Fig. 
615  reveals  the  exact  position  of  the  delayed  tooth  and  shows  the  im- 
portance of  making  room  for  its  eruption.  Fig.  616  shows  a  second 
bicuspid  caught  under  the  shoulder  of  a  first  bicuspid,  and  suggests  that 
it  can  be  released  by  forcing  the  latter  into  an  upright  position. 

The  exact  position  of  a  delayed  canine  may  be  revealed,  and  the 
question  settled  whether  it  be  possible  for  it  to  erupt  without  assistance, 
or  whether  it  can  even  be  forcibly  erupted. 


Fig.  615. 


Fig.  616. 


In  some  cases  a  deciduous  tooth  remains  in  place  long  after  the  time 
when  it  should  have  fallen  out.  It  may  be  so  firm  as  to  cause  serious 
doubts  about  the  advisability  of  extracting  it,  even  though  there  is  mal- 
occlusion while  it  is  in  place.  The  skiagraph  will  reveal  the  presence 
or  absence  of  the  bicuspid,  and  show  whether  extraction  should  be 
resorted  to  or  not. 

The  method  of  making  the  skiagraph  is  thus  described^  bv  C. 
Edmund  Kells,  D.  D.  S.,  of  New  Orleans  : 

"One  of  the  requirements  in  o])taining  a  skiagraph  is  that  the  object 
to  be  pictured  and  the  plate  or  film  must  be  held  perfectly  still  during 
the  process.  It  is  frequently  possible  to  cut  tlie  film  the  proper  shape, 
inclose  it  in  a  black  Hight-proof )  envelope,  and  allow  the  patient  to 
hold  it  in  the  moutli  in  the  desired  position  ;  but  on  general  principles 
this  is  not  satisfactory,  more  especially  with  children,  as  it  is  liable  to  be 
moved  during  the  exposure. 

'  Dental  Cosmos,  October  1899,  vol.  xli.  p.  1014. 


696  ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE 

"  The  method  now  employed,  after  much  experimenting  in  that  line, 
is  as  follows  : 

"  A  cast  is  made  of  the  portion  of  the  mouth  to  be  skiagraphed, 
and  a  small  piece  of  modeling  compound  moulded  over  the  crowns  of 
the  teeth  thereon.  A  piece  of  aluminum  (this  metal  being  almost 
transparent  to  the  rays)  of  about  26  or  28  gauge  is  cut  to  the  desired 
size  and  shape  and  bent  to  fit  the  cast  as  well  as  possible.  This  is 
slotted  along  the  edge  toward  the  crowns  of  the  teeth,  and  thereby 
attached  to  the  modeling  compound  referred  to  above.  This  forms 
a  convenient  little  film-holder,  which  when  placed  in  the  mouth  will 
allow  the  patient  to  close  the  teeth  upon  it,  and  thus  hold  it  securely 
in  position,  without  danger  of  its  moving,  for  a  much  longer  time  than 
is  necessary  to  take  the  picture. 

"  The  next  step  is  to  cut  the  plate  or  celluloid  film,  whichever  is  to 
be  used,  to  the  proper  size  and  envelop  it  neatly  in  black  paper,  gluing 
down  all  the  edges  with  paste,  and  securing  it  to  the  plate-holder  by 
two  or  more  small  aluminum  clamps. 

"  This  is  all  that  is  usually  necessary ;  but  if  it  is  deemed  advisable 
to  protect  the  envelope  from  moisture,  as  is  sometimes  the  case,  more 
especially  for  lower  teeth,  then  it  is  covered  with  thin  tin  foil  or 
waterproof  paper  neatly  pasted  down,  care  being  taken  not  to  have  the 
foil  (if  that  is  used)  doubled  upon  the  side  to  be  exposed.  While  this 
may  appear  to  be  a  long  process,  it  is  quickly  accomplished,  and  the 
invariably  satisfactory  results  obtained  warrant  the  trouble  taken. 

"  The  patient  is  then  seated  in  a  chair  with  a  photographer's  head- 
rest to  hold  the  head,  the  Tesla  screen  put  in  place,  and  the  tube  brought 
to  about  ten  or  twelve  inches  from  the  face  and  placed  so  as  to  throw 
the  best  shadow  of  the  parts  upon  the  film.  The  length  of  exposure 
depends  upon  the  thickness  of  the  parts  to  be  penetrated,  the  working 
condition  of  the  apparatus,  and  the  distance  of  the  patient  from  the 
tube,  the  time  being  proportional  to  the  square  of  the  distance.  From 
sixty  to  ninety  seconds  are  necessary  for  ordinary  cases,  ranging  perhaps 
up  to  one  hundred  and  twenty  seconds  for  third  molars  and  heavy  jaws, 
while  twenty  to  forty  seconds  are  sufficient  for  some  favorable  cases  in 
thinner  bones." 

In  some  of  the  large  cities  skiagraphs  can  be  readily  obtained  from 
experts  with  the  Rontgen  ray,  who  make  it  a  business  to  accommodate 
physicians  and  others  desiring  their  services.  Any  expert  dentist  with 
a  slight  knowledge  of  photography  can  readily  prepare  the  film  for  the 
purpose. 

(e)  Pernicious  Habits. — The  habit  of  thumh-Huching  may  cause 
upper  protrusion  (see  Fig.  757),  lack  of  anterior  occlusion  (Fig.  801), 
or  a  constricted  arch  (Fig.  798). 


ETIOLOGY  OF  DENTAL  IRREGULARITIES.  697 

The  habit  of  sucking  the  finger  or  lip  may  cause  protrusion  of  either 
jaw  according  to  the  position  of  tlie  finger  or  lip. 

While  thumb-sucking  sometimes  causes  the  irregularities  mentioned, 
it  is  not  a  frequent  cause,  and  it  is  a  singular  fact  that  the  habit  does 
not  cause  irregularity  of  the  deciduous  teeth. 

.  The  habit  of  moutli-b reathing ,  whether  owing  to  nasal  obstructions 
or  not,  may  cause  lack  of  anterior  occlusion — see  (e),  page  786 — or 
apparent  lower  protrusion — see  (t),  page  774. 

(/)  Other  Causes  of  Irregularity. — Obstruction  of  the  nasal  cavity 
by  a  deflected  septum,  enlarged  turbinate  bones,  polypi,  adenoid  growths 
in  the  nasopharynx,  enlarged  tonsils,  or  any  other  cause,  by  preventing 
free  circulation  of  air  through  the  nasal  cavity,  may  be  the  cause  of  a 
lack  of  development  of  the  frontal,  sphenoidal,  ethmoidal,  and  maxil- 
lary bones.  This  lack  of  development  may  produce  a  high  and  con- 
tracted vault,  with  a  narrow  and  small  arch  and  consequent  crowding 
of  the  teeth  into  various  irregularities. 

Lack  of  development  of  the  intermaxillary  bone  may  cause  (a)  a  pointed 
arch  (page  757),  (6)  lack  of  anterior  occlusion  (page  786),  or  (c)  prom- 
inent canines  and  depressed  laterals — see  («),  page  745. 

Disparity  in  size  betiveen  the  teeth  and  the  jaw  may  be  due  to  either 
of  two  widely  different  causes,  and  yet  produce  several  similar  irreg- 
ularities. 

(1)  This  disparity  in  size  may  be  due  to  teeth  too  large  for  the  jaw 
(indirect  heredity — page  690). 

(2)  It  may  be  due  to  premature  loss  of  deciduous  second  molars  and 
a  forward  movement  of  the  permanent  first  molars,  thus  shortening  the 
arch  and  making  it  too  small  for  the  ten  teeth  that  are  to  occupv  it. 

The  result  may  be — 

(a)  Prominent  canines  and  depressed  laterals  (Class  7,  page  745). 

(6)  Pointed  arch  (Class  8,  page  757). 

(c)  Upper  protrusion  (Class  9,  page  760). 

(d)  Constricted  arch  (Class  12,  page  784). 

(e)  Lower  protrusion  (Class  10,  page  773). 

The  same  condition  in  both  jaws  at  once  may  cause  similar  irregu- 
larities in  both  jaws.  One  of  the  most  notable  of  these  is  double  pro- 
trusion (Class  11,  page  782). 

Loss  of  the  deciduous  second  molar  on  one  side  may  cause  anv  of 
these  irregularities  on  that  side  only,  such  as  a  semi-constricted  or 
semi-pointed  arch. 

Chang-es  in  Surrounding-  Tissues  when  Teeth  are  Moved. — 
1.  Resorption  axd  Deposition. — When  a  single  tooth  is  moved  in 
any  direction,  there  is  first  a  compression  of  the  soft  and  then  of  the  hard 
tissues  in  front  of  the  tooth,  and  at  the  same  time  a  stretching  of  the 


698  ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 

peridental  membrane  behind  the  tooth.  This  is  succeeded  by  resorp- 
tion of  the  hard  tissues  in  front  by  osteoclasts  and  aforiaation  of  new 
hone  by  the  osteoblasts  behind  the  moving  tooth. 

This  latter  action  is  much  slower  than  the  former,  and  depends  on 
the  tooth  being  held  firmly  in  its  advanced  position.  Any  slight  return 
will  interfere  with  the  formation  of  new  tissue,  and  a  tooth  repeatedly 
moved  forward  and  allowed  repeatedly  to  recede  will  never  become  firm. 

When  a  tooth  is  rotated  in  its  socket,  there  must  be  a  stretching 
of  the  fibers  of  the  peridental  membrane.  If  the  fibers  had  not  con- 
siderable elasticity,  those  opposing  the  rotation  of  the  teeth  would  be 
ruptured  instead  of  stretched,  and  would  not  tend  to  twist  the  tooth 
back  to  its  old  position.  A  tootli  is  sometimes  forced  back  by  the  pres- 
sure of  adjoining  teeth,  but  such  contingencies  are  not  here  under  con- 
sideration. If  the  root  is  curved  or  is  not  round,  there  may  be  some 
resorption  and  rebuilding  of  the  walls  of  the  alveolus. 

2.  Bending  of  the  Alveolar  Ridge. — When  several  teeth  are 
moved  in  the  same  direction  at  the  same  time  there  is  a  movement  of 
the  alveolar  ridge  as  if  it  were  a  semi-plastic  mass.  This  movement  is 
easily  proved  by  the  following  observations  : 

After  a  case  of  upper  protrusion  is  reduced  the  labial  portion  of  the 
alveolar  ridge  appears  no  thicker  than  before.  If  the  only  movement 
were  of  the  roots  through  the  ridge  by  resorption  in  advance  of  the 
moving  tooth  and  formation  of  new  bone  behind,  the  labial  portion 
would  remain  as  prominent  as  before. 

In  spreading  the  arch  rapidly,  if  movement  took  place  only  after 
resorption,  the  teeth  might  be  pushed  out  of  the  ridge,  but  the  external 
plates  of  the  alveolar  process  will  be  found  no  thinner  than  before, 
while  the  vault  of  the  palate  is  perceptibly  broadened. 

Dr.  C.  S.  Case  says  that  when  teeth  and  roots  are  moved  forward, 
sometimes  ridges  will  appear  on  the  outer  surface  of  the  alveolar 
process,  but  that  the  spaces  or  hollows  between  will  soon  fill  up  so  as  to 
present  an  even  surface. 

3.  Separation  of  the  Superior  Maxill.e  at  the  Symphysis. 
— When  strong  pressure  is  applied  upon  molars  and  bicuspids  to  spread 
the  arch  the  superior  maxillae  may  be  separated  at  the  symphysis.  (See 
Figs.  617  and  618.) 

Such  separation  was  first  recorded  by  Dr.  E.  C.  Angell  of  San  Fran- 
cisco^ in  1885,  and  has  been  noticed  by  Guilford,  Black,  Talbot,  Farrar, 
Ottolengui,  and  others  since.  Drs.  Talbot"  and  Ottolengui^  regard  it 
as  an  advantage  as  giving  room  for  re-arranging  crowded  incisors  more 

^  Dental  Cosmos,  vol.  ii.  p.  540. 

-Discussion  in    World's  Columbian  Dental  Congress,  vol.  ii.  p.  722. 

*  Dental  Practitioner,  vol.  xxxv.,  No.  4,  October  1894. 


ETIOLOGY  OF  DENTAL  IRREGULARITIES.  699 

Fig.  617. 


Symphysis  of  superior  maxillae,  before  spreading  arch. 

quickly  than  in  any  other  way  and  maintaining  crowns  and  roots  in  an 
upright  position. 

Fig.  618. 


Separation  of  superior  maxillse  at  symphysis,  after  spreading  arch. 

4.  Depression  of  the  Roots  in  the  Sockets. — In  reducing 
cases  of  lack  of  anterior  occlusion  by  means  of  elastics  extending  from 
a  chinpiece  to  a  cap  to  the  top  of  the  head,  Prof.  Guilford  ^  savs  : 
"The  condyles  of, the  lower  jaw  will  be  tipped  somewliat  out  of  their 
cavities,  and  the  latter  be  partially  filled  up  with  new  ossific  material ; 
at  the  same  time  the  tendency  will  be  to  shorten  the  posterior  occlud- 
ing teeth  by  forcing  them  farther  into  their  sockets." 

Charles  S.  Tomes  ^  in  a  similar  case  questioned  whether  "the  closure 
of  the  front  teeth  was  effected  by  an  elongation  of  the  ascending 
ramus  of  the  jaw  or  by  the  antagonizing  teeth  being  depressed  and,  so 
to  speak,  forced  farther  into  their  sockets,"  and  concludes,  "  I  am 
inclined  to  think  the  latter  is  the  true  explanation." 

1  Orthodontia,  2d  ed.,  p.  196.  ^  Kingsley's  Oral  Defoi-mities,  p.  121. 


700  ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 

Pathological  Conditions  which  may  be  Caused  by 
Irregularities  of  the  Teeth. 

Under  this  head  may  be  mentioned  dental  caries,  gastric  disorders, 
and  deposition  of  salivary  calculns. 

Caries. — In  the  normal  arch  the  teeth  tonch  each  other  at  one  point 
only,  and  fluids  are  freely  circulated  between  and  about  them  by  the 
tongue,  lips,  and  cheek.  When  the  teeth  are  irregularly  arranged  broad 
surfoces  often  come  in  contact,  the  convex  surface  of  one  incisor  may 
be  partially  imbedded  in  the  concave  surface  of  another,  or  three  teeth 
arranged  as  in  a  triangle  form  between  them  a  cul-de-sac.  In  all  such 
cases  the  maintenance  of  cleanliness  is  difficult  if  not  impossible,  and 
caries  is  the  probable  result. 

Dyspepsia. — Any  deviation  from  the  normal  arch  will  cause  also 
a  deviation  from  the  normal  occlusion,  so  that  proper  trituration  of  the 
food  is  interfered  with  if  not  positively  prevented.  Such  lack  of 
thorough  mastication  will  throw  unusual  burdens  upon  the  digestive 
organs,  resulting  in  their  greater  or  less  derangement. 

The  question  of  occlusion  is  exceedingly  important,  and  often  decides 
the  method  of  treatment  of  an  irregularity  or  of  making  room,  or  of 
undertaking  any  treatment  whatever. 

In  most  cases  of  complicated  irregularity  there  is  already  mal- 
occlusion of  the  masticating  teeth,  and  every  endeavor  should  be  made 
to  move  the  teeth,  so  as  to  improve  the  occlusion  and  make  it  as  nearly 
normal  as  possible. 

When  the  occlusion  is  already  normal  and  the  irregularity  is  slight 
but  cannot  be  reduced  without  seriously  deranging  one  or  both  sides  of 
the  mouth,  it  may  be  best  to  permit  the  irregularity  to  remain,  as  the 
least  of  the  two  evils. 

In  any  case  of  widening  or  spreading,  should  either  arch  be  made  too 
wide  for  the  other,  that  also  should  be  spread  to  restore  or  imi)rove  the 
occlusion. 

If  either  arch  be  too  small  for  the  other,  the  sole  object  in  spreading 
may  be  to  improve  the  occlusion. 

If  in  any  case  room  must  be  made  by  extraction,  the  most  serious 
consideration  must  be  given  to  the  choice  of  the  tooth  or  teeth  whose 
removal  will  least  derange  the  occlusion,  if  already  good ;  and  if  other- 
wise, selection  may  be  so  made  as  to  improve  it. 

The  tooth  most  often  under  discussion  in  this  respect  is  the  perma- 
nent first  molar.  This  is  a  very  valuable  tooth  for  mastication,  and  its 
loss  may  render  all  the  teeth  on  that  side  of  the  mouth  useless  for  that 
function.  The  teeth  back  of  the  space  may  tip  forward  and  those  ante- 
rior to  it  may  tip  backward,  so  that  they  all  present  only  points  and 


ACCIDENTS   WHICH  MAY  HAPPEN  DURING   TREATMENT.     701 

cusps  to  the  cusps  of  opposing;  teeth,  instead  of  the  normal  interlock- 
ing of  cusps  which  gives  the  greatest  efficiency. 

The  question  as  to  the  extraction  of  a  tooth  will  depend  also  on 
its  condition.  In  the  writer's  opinion  it  will  be  better  in  many  cases 
to  crown  the  roots  of  a  molar  decayed  too  much  for  filling,  and  remove 
some  other  tooth  that  is  less  useful  in  mastication.  (This  question  is 
further  discussed  on  page  745.) 

Salivary  Calculus. — As  the  accumulation  of  salivary  calculus  is 
impossible  upon  parts  of  the  teeth  subjected  to  use  in  mastication  or 
easily  cleansed  with  the  brush,  so  any  abnormality  of  arrangement  that 
prevents  thorough  use  of  the  brush  favors  the  deposit,  with  all  of  its 
possible  consequences. 

Accidents  which  may  Happen  during  Treatment. 

Death  of  the  Pulp. — This  may  occur  from  strangulation  at  the 
apical  foramen  from  too  rapid  movement  of  the  tooth.  The  possibility 
of  this  accident  is  least  when  movement  is  begun  while  the  apical  fora- 
men is  large,  before  the  root  is  completely  formed  ;  it  increases  with  the 
age  of  the  patient,  and  is  greatest  after  the  root  is  fully  formed  and  the 
foramen  is  constricted  to  its  permanent  size. 

Death  of  the  pulp  may  also  occur  from  rupture  of  the  bloodvessels 
at  the  apex  of  the  root  from  too  rapid  elevation  of  the  tooth.  The 
liability  of  such  accident  will  vary  according  to  the  age  of  the  patient 
and  size  of  the  apical  foramen. 

Rupture  of  the  Pericementum. — This  may  occur  also  from  too 
rapid  elevation  of  a  tooth.  After  such  an  accident,  a  tooth  returned 
to  its  socket  would  be  in  the  condition  of  a  replanted  tooth,  subject 
to  the  same  chances  of  attachment  and  retention. 

Permanent  Enlargement  of  the  Alveoli. — Dr.  Talbot '  says  : 
"The  probability  of  a  perfectly  satisfactory  result  in  regulating 
decreases  yearly  after  the  age  of  puberty,  and  after  the  age  of  twenty- 
six  the  chances  of  a  really  satisfactory  result  are  very  meagre,  for  at 
this  time  the  entire  osseous  system  is  fully  developed  and  there  is  little 
probability  of  extensive  deposit  of  ossitic  material." 

The  writer  would,  however,  fix  the  date  later  than  that — perhaps 
at  thirty  years. 

Pressure  at  any  age  will  cause  resorption,  therefore  teeth  may  be 
moved  in  the  case  of  adults,  though  more  slowly  on  account  of  the  greater 
rigiditv  of  the  alveolar  process.  Greater  force  will  be  needed  to  produce 
resorption  in  advance  of  the  moving  tooth,  and  there  is  a  possibility, 
even  a  probability,  that  no  ossific  deposit  will  take  place  behind  the 

'  Irref/ulurities  of  the  Teeth  and  their  Treatment,  2(1  ed.,  p.  172. 


702 


ORTHODONTIA  AS  AN  OPERATIVE  PROCEDURE. 


Fig.  619. 


root.     The  result  is  an  enlarged  socket  in  which  the  tooth  never  again 

becomes  rigid. 

Permanent  enlargement  of  the    alveoli    may  occur  also   from   not 

retaining  teeth  fixedly  in  their  new  position  but  allowing  them  to  move 

back  and  forth.     The  action  of  the  osteoblasts  in  forming  new  bone  is 

thus  interfered  with  so  much  as  to  absolutely  prevent  it,  and  the  result 

is  an  enlarged  alveolus. 

Injury  to  the  Enamel  (Caries). — This  may  occur  from  too  long 

retention  of  either  regulating  or  retaining  appliances  in  contact  with 

the  teeth. 

Bands  that  are  to  be  retained  more  than  a  few  weeks  should  be 

cemented  upon  the  teeth  and  carefully  watched,  as  a  loose  band  will 
surely  result  in  a  softening  of  the  enamel  under 
it,  sometimes  even  to  the  extent  of  forming  a 
cavity. 

Retaining  appliances  should  be  so  constructed 
that  no  flat  or  broad  surfaces  remain  in  contact 
with  the  teeth.     A  round  wire  is  as  efficacious 

as  a  flat  bar,  and  the  tooth  under  it  is  easily  kept  clean,  as  the  point 

of  contact  is  so  small.     (See  Fig.  619.) 

Appliances,  Materials,  Methods,  and  Forces  Employed. 

Definitions. — To  prevent  repetitions  a  few  appliances  and  materials 
will  be  briefly  described. 

Rubber  Band. — A  section  cut  from  French  rubber  tubing  from 
i  to  i  of  an  inch  in  diameter  and  from  g\  to  i  of  an  inch  wide.  (See 
Fig.  620.)  These  lose  their  elasticity  by  remaining  stretched,  and  should 
be  changed  at  least  twice  a  week. 


Round  and  flat  contacts 
in  regulating  fixtures. 


Fig.  020. 


Fig.  621. 


Rubber  tubing  for  bauds. 


Bicuspid.  Molar. 

Adjustable  bands  (Angle). 


Gauge. — In  indicating  the  thickness  of  plate  and  size  of  wire  the 
number  referred  to  is  that  of  B.  &  S.  gauge,  c.  g.  wire  No.  20,  plate 
No.  27,  etc. 

Tube  or  Tubing. — Made  of  a  strip  of  platinum-gold  or  German 
silver  No.  27  to  No.  32  gauge  and  \  of  an  inch  or  less  wide,  drawn 
through  successive  holes  in  a  draw-plate  until  a  tube  is  formed  and 
reduced  to  the  desired  size.     (See  Fig.  628.)     To  make  a  tube  to  fit  any 


APPLIANCES,  MATERIALS,  METHODS,  AND  FORCES  EMPLOYED.    703 

desired  wire  or  screw,  take  a  strip  three  and  one-third  times  the  diam- 
eter of  the  wire  or  screw. 

Magill  Band. — The  invention  of  Dr.  W.  E.  Magill.     A  strip  of 
platinum,  gold  plate,  or  German  silver,  No.  30  to  36  B.  &  S.  gauge, 
preferably    the   latter,    from   ^  to   ^  of  an   inch  wide, 
bent  around  a  tooth  in  the  mouth  or  on  a  plaster  cast,  ^^^'  ^•^^" 

and  soldered  at  the  overlapping  ends.    This  is  cemented     j^^^  f^^^ 
to  a  tooth  with  zinc  phosphate.     (See  Figs.  622,  647,        Magin  bands 
et  seq.) 

Adjustable  Band  (Angle's). — A  band  of  German  silver  from 
■|  to  1  of  an  inch  wide  and  No.  36  B.  &  S.  gauge,  to  one  end  of  which 
is  soldered  a  short  tube  and  to  the  other  a  screw,  which  is  passed 
through  the  tube  and  tightened  around  the  tooth  with  a  nut.  (See 
Fig.  621.)  Cement  should  be  placed  inside  the  band  before  apply- 
ing it. 

Band  Ribbon. — This  is  best  made  from  platinum  or  German  silver 
wire  No.  13,  rolled  to  No.  34  or  No.  36  plate.  This  is  tougher  than 
when  cut  from  plate  of  the  same  thickness.  For  the  anterior  teeth  the 
writer  often  uses,  however,  gold-faced  platinum  rolled  to  the  gauge 
mentioned.  It  has  the  strength  of  platinum  and  the  color  of  gold, 
which  is  preferred  by  many  patients. 

To  this  band  may  be  soldered  a  tube,  hook,  screw,  or  any  appliance 
desired. 

Jack-screw  (Angle's). — A  tube  pointed  at  one  end,  in  which  is 

inserted  a  screw  about  No.  16  B.  &  S.  ffausre, 
Fig.  623.  .  ,  .  ,,  -,     n   ^         f 
^^^           with  a  nut  resting  on  the  open  end  oi  the  tube. 

V^,T.^^^^^  The  end  of  the  screw  is  flattened  or  bifur- 

Angle  s  jack-screw. 

cated.     The  length  of    the  tube  determines 
the  length  of  the  jack-screw.     (See  Figs.  623  and  G43.) 
Drag-screw   (Angle's). — A   wire  t-     />o^ 

^                   -^                                                   Fig.  624. 
bent    at    right    angles    at    one     end,  , .- -  - ■ ^a — O 

threaded  at  the  other  with  a  nut.    (See 

r  ig.  0-<4.  j  r^^^aiB^^Bmm^^Kai^m^^nCMn 

Piano  "SYire. — Piano  strings.   Steel     ^  .    ,  ,  . 

'^  Angle  s  drag-screw. 

wire,    elastic,  yet  soft  enough  to  bend 

easily  with  pliers,  from  No.  20  to  No.  24  B.  &  S.  gauge  :  used  for 
springs  and  elastic  levers.  (No.  20  B.  &  S.  gauge  corresponds  to 
about  No.   15  of  piano  wire  gauge.) 

Ligatures. — Floss  silk  well  waxed. 

Twisted  Ligatures. — Twisted  silk  No.  A  0  or  00  or  linen  thread 
unbleached  No.  50,  well  waxed. 

These  are  very  useful  in  moving  teeth,  either  ligated  directly  on  the 
teeth  or  in  connection  with  other  appliances.     When  tied  tightlv  from 


704 


ORTHODONTIA  AS  AN  OPERATIVE  PROCEDURE. 


one  tooth  to  auother  there  is  an  immediate  movement  by  slight  com- 
pression of  the  peridental  membrane ;  then  as  the  twisted  fibers  swell 
the  ligature  is  shortened  and  more  ])ressure  exerted. 

It  is  to  be  understood  that  in  the  majority  of  illustrations  in  this 
chapter  in  which  rubber  bands  are  shown  as  the  moving  force,  ligatures 
may  be  substituted.     Tliey  should  be  renewed  every  day  or  two. 

Twisted  avire  ligatures  of  platinum,  copper,  brass,  or  German 
silver  wire  are  excellent  for  intermittent  movement  of  teeth.  Dr.  Angle 
suggests  No.  28  B.  &  S.  gauge  as  the  best  size  (Figs.  726  and  727). 

Norton-Talbot  or  Coil  Spring. — A  spring  of  piano  wire  No. 
20  to  No.  24  B.  &  S.  gauge  coiled  upon  itself  one  or  more  times. 

Ftg.  G25. 


Talbot  springs. 


The  best  size  of  coil  is  that  made  around  a  piece  of  the  same  wire, 
(See  Figs.  625,  741,  and  742.) 

Matteson  Spring. — A  spring  of  piano  wire  No.  20  to  No.  24  B.  & 
S.  gauge,  Avith  two  coils  a  half-inch  or  more  apart.  (See  Figs.  626,  651, 
and  744.) 


Fig.  626. 


627. 


Fig.  628. 


Matteson  spring. 


Swaged  caps. 


Metallic  tubing. 


Cement. — Zinc  phosphate  is  more  adhesive  than  oxychlorid  of  zinc  ; 
it  should  be  mixed  thin  and  applied  to  the  tooth  and  band  or  cap. 
Rubber  dam  should,  if  possible,  be  applied  to  the  teeth  before  using 
the  cement. 

Swaged  Caps  (Matteson's). — Caps  swaged  to  fit  over  the  whole 
or  part  of  a  tooth  and  secured  with  cement.  To  tliese  caps  are  soldered 
hooks,  bars,  tubes,  levers,  etc.     (See  Fig.  627.) 


APPLIANCES,  MATERIALS,  METHODS,  AND  FORCES  EMPLOYED.   705 

Lock-nut. — A  second  nut  screwed  up  against  the  first — neces^ 
sary  in  some  cases  to  prevent  retrograde  action  by  the  patient's 
tougue. 

Labial  Bow. — A  bow  of  stiff  wire,  German  silver,  or  clasp  gold, 
about  No.  16  B.  &  S.  gauge,  extending  from  the  buccal  surface  of  the 
teeth  on  one  side  of  the  mouth  around  the  arch  to  a  corresponding  posi- 
tion on  the  other  side.  It  may  be  held  in  place  by  inserting  the  ends 
in  a  plate  (Fig.  711)  or  in  tubes  soldered  to  bands  cemented  on  suitable 
teeth  (Figs.  713,  729,  759).  The  euds  of  the  bow  may  be  screw-cut 
and  furnished  with  nuts,  as  shown  in  these  figures,  or  bent  in  bayonet- 
shape  (Fig.  741). 

Lingual  Bow. — A  similar  bow  on  the  lingual  surface  of  the  arch, 
with  the  ends  inserted  in  tubes  on  the  lingual  surface  of  bicuspid  or 
molar  bands,  screw-cut  with  nuts  (as  in  Fig.  715  or  716)  or  bent  into 
hooks  (as  in  Fig.  667). 

Labial  and  lingual  bows  are  often  used  advantageously  together 
and  attached  to  the  same  teeth,  as  in  Fig.  669  or  713. 

Author's  Partly- made  Appliances. — Fig.  629  shows  the  writer's 
system  of  partly-made  appliances.     Each  consists  of  a  piece  of  band- 


FiG.  029. 


F  G  H 

Partly-made  appliances. 


ribbon  bent  into  an  open  loop.  To  each  is  soldered  a  tube,  hori- 
zontal or  crosswise,  round  or  flat,  or  a  wire,  in  line  or  at  right  angles. 
These  can  be  made  by  the  practitioner  in  leisure  moments,  and  kept 
in  stock.  Whon  a  patient  is  in  the  chair,  one  of  the  open  bands  can 
be  bent  around  any  tooth,  with  the  tube  or  wire  in  any  position  de- 
sired. The  open  ends  can  then  be  drawn  tightly  around  the  tooth 
and  the  sides  burnished  to  fit  accurately.     Remove  the  baud,  cut  the 

•15 


706 


ORTHODONTIA   AS  AN   OPERATIVE  PROCEDURE. 


ends  as  shown  in  Fijj^.  G.30,  a,  bend  one  over  the  other,  as  in  B, 
pineh  them  tightly  together,  so  as  to  hohl  while  soldering.  Grasp  the 
band  with  the  pliers  as  shown  in  Fig.  Gol,  and  ajiply  solder  and 
heat  to  the  inside  of  the  joint.     The  pliers  will  ])roteet  the    tnbe  (»r 


Fig.  630. 


A    !lf  B 

A,  Baud  fitted;  D,  ready  fur  soldering. 


wire  from  unsoldering.  The  surplus  ends  can  then  be  cut  away,  as  in 
making  a  plain  band.  E,  in  Fig.  629,  shows  two  open  bands  soldered 
to  a  long  tube  for  making  a  double  anchorage  appliance,  such  as 
shown  in  Fig.  730.     D  has  a  flat  tube,  which  may  be  used  as  in  Fig. 


Fig.  631. 


Soldering  joint  in  open  band. 


739.  F  will  make  a  retainer,  like  Fig.  653  or  677,  while  G  and  H 
can  be  bent  into  hooks  for  various  purposes. 

The  writer  finds  these  "  partly-made  appliances  "  a  great  saving  of 
time,  as  a  great  variety  of  complete  appliances  can  be  made  from  them 
while  the  patient  is  in  the  chair. 

Figs.  745  and  746  show  how  an  expander  can  be  made  in  a  similar 
manner. 

Force. — ^^ Constant  Force." — That  exerted  by  compressed  rnl)l)cr 
or  a  spring  of  clasp  gold  or  piano  wire. 

"  Intermittent  Force." — That  exerted  by  a  scrcAV,  wliich  allows 
periods  of  rest  after  each  application  ;  also  that  exerted  by  compressed 
wood  or  twisted  ligatures  of  silk  or  linen. 


APPLIANCES,  MATERIALS,  METHODS,  AND  FORCES  EMPLOYED.   707 


Methods. — Xo  one  '^  method  "  is  applicable  to  all  cases,  so  that  it  is 
necessary  to  select  from  various  methods  the  simj)lest  and  most  efficient 
for  treating  each  kind  of  irregularity.  During  the  last  twenty  years 
there  have  been  presented  by  specialists  in  orthodontia  many  different 
plans  of  regulating.  These  are  known  as  tlieir  special  "methods"  and 
are  designated  by  the  names  of  their  originators. 

The  first  extensive  description  of  regulating  appliances  was  that 
by  Dr.  Noemax  W.  Kixgsley,  in  his  book  on  Oral  Deformities, 
in  1880.  Most  of  the  appliances  described  in  his  book  were  taken 
from  original  articles  previously  written  by  him  for  dental  jour- 
nals, while  a  number  were  selected  from  articles  by  other  well-known 
writers. 

The  first  to  claim  a  distinct  method  or  system  was  Dr.  J.  N.  Farrar 
in  articles  published  about  1875,  and  further  elucidated  in  book  form 
in  1888.  His  system  is  based  upon  the  adoption  of  the  screw  as  a 
motive  force.  The  originator  claims  the  screw  to  be  the  only  force 
which  should  be  used,  because  it  is  intermittent  and  gives  the  parts  a 
period  of  rest  after  each  application.  Very  ingenious  devices  have  been 
invented  by  him  by  wliich  the  screw  is  applied  successfully  to  all  kinds 
of  movement,  but  as  a  rule  his  appliances  are  more  complicated  than 
those  of  any  other  system. 

The  Coffin  method  was  introduced  at  the  International  Medical 
Congress  in  London,  in  1881,  by  Walter  H.  Coffin.     The  elasticity  of 


Fk;.  fi.'^-J. 


Cofliu  split  plate  for  spreading  the  upper  arch. 


piano  wire  is  used  as  a  motive  force,  by  anchoring  it  in  vulcanite  plates. 
The  most  notable  exam])le  of  this  method  is  the  Coffin  split  plate  for 
spreading  the  arch.     (See  Figs.  632,  633,  and  634.) 

The  Angle  method  depends  chiefly  on  the  screw  for  force,  though 
piano  wire  and  twisted  wire  ligatures  are  also  used. 

Dr.  Angle  M'as  the  first  to  advocate  extensive  use  of  German  silver 
for  regulating  appliances.  The  advantages  of  this  alloy  are  such  that 
it  now  is  more  largely  employed  than  any  other  material. 


708 


ORTHODONTIA  AS  AN  OPERATIVE  PROCEDURE. 


A   new   application   of  force   has   been   lately   introdueed,    viz.    the 
elongation  of  win;  by  pinching  or  compressing  it  with  s])ecial  round 


Fio.  633. 


Fig.  634. 


^yip'i^k 


<//' 


Coffin  spring  plate  for  lower  arch. 


Coflin  spring  plate  for  single  teeth. 


pliers,  shown  in  Fig.  676.  This  may  be  used  in  many  places  in,stead 
of  the  jack-screw. 

The  ccHistruction  of  jack-screws  and  drag-screws  has  been  greatly 
simplified.  Thin  soldered  bands  are  cemented  to  the  teeth,  or  "  anchor 
bands,"  the  ends  of  which  are  united  by  screw  and  nut.  To  these 
bands  tubes  arc  soldered  for  the  attachment  of  appliances  which  are  so 
constructed  that  force  once  applied  need  not  be  withdrawn  till  the  en- 
tire movement  is  accomplished.  A  rest  may  be  allowed,  but  no  back- 
ward movement.  Thus  no  interference  is  made  with  building  up  the 
tissues  behind  the  tooth. 

Appliances,  complete  or  in  parts,  to  be  adajited  to  special  cases  have 
been  put  on  the  market  by  Prof.  Angle.  These  more  nearly  fill  the 
want  of  one  who  cannot  make  all  his  appliances. 

Dr.  V.  H.  Jackson's  method  consists  in  the  use  of  piano  wire  or 
other  elastic  wire  for  force  and  the  attachment  of  the  wire  to  the  teeth, 
in  most  cases,  by  means  of  a  "crib"  made  of  the  wire  itself,  and  not 
by  means  of  bands  or  plates. 

For  full  descriptions  of  these  methods  the  student  is  referred  to  the 
writings  of  the  authors  themselves.^ 

General  Directions. 

All  metallic  bands  which  are  to  remain  in  contact  with  the  teeth  for 
any  length  of  time  should  be  cemented  to  them  with  zinc  phosphate,  to 
prevent  deleterious  action  of  acids  of  fermentation  which  would  be  gen- 
erated and  retained  between  bands  and  teeth.  The  rubber  dam  should 
be  applied  whenever  possible  to  the  tooth  to  be  banded,  and  to  one  or 

'In  the  American  Text-Book  of  Pros^thetic  Dentistry,  edited  by  Dr.  Charles  J.  Essig, 
will  be  found  a  chapter  on  "Orthodontia  Technic,"  by  the  writer,  in  which  tlie  making 
of  regulating  appliances  is  described  much  more  fully  than  is  possible  here. 


GENERAL  DIRECTIONS.  709 

more  teeth  on  each  side.  In  some  cases  it  may  be  applied  to  fourteen 
teeth  at  once.  The  teeth  shoukl  be  thoroughly  dried  and  cleaned  ;  the 
cement  mixed  thin  is  applied  to  the  tooth  and  to  the  inside  of  the  band, 
and  the  latter  is  pushed  or  malleted  firmly  to  place.  The  teeth  should 
be  kept  dry  for  ten  minutes  or  longer  after  the  cement  is  applied.  If 
this  is  not  possible,  where  napkins  are  used,  varnish  or  melted  paraffin 
may  be  applied  over  the  cement  at  the  edges  of  the  band  for  the  pur- 
pose of  excluding  moisture  as  long  as  possible.  Bands  may  be  fast- 
ened in  a  similar  way  by  chloro-percha. 

During  the  time  of  regulating  and  while  retaining  appliances  are  in 
position,  bands  should  be  examined  frequently.  If  one  becomes  loose 
it  should  be  removed,  and  cemented  on  again. 

The  patient  should  keep  a  brush  at  the  office  for  use  when  appli- 
ances are  removed,  and  the  appliances  should  be  very  carefully  cleansed 
by  the  operator  before  they  are  replaced.  When  plates  are  used  espe- 
cial care  should  be  taken. 

During  the  time  that  immovable  appliances  are  worn,  the  patient 
should  be  provided  with  a  bulb  syringe  with  which  dilute  listerine  or 
other  antiseptic  mouth-wash  can  be  thoroughly  applied  under  bars, 
screws,  springs,  etc.,  or  wherever  the  brush  cannot  reach. 

Teeth  should  generally  be  moved  a  little  farther  than  the  desired 
position,  because  there  is  almost  always  a  slight  return  of  the  tooth 
toward  its  old  position  after  the  retaining  appliance  is  removed.  This 
retrograde  movement  is  less  likely  to  occur  with  canines  when  room  has 
been  made  by  extraction. 

The  age  at  ichich  correction  should  be  begun  depends  on  the  presence 
of  sufficient  teeth  for  anchorage.  It  should  be  commenced  as  soon  as 
appliances  can  be  used  to  advantage. 

The  writer  believes  in  early  correction,  in  some  cases  as  early  as  the 
age  of  seven  years.  The  advantage  of  early  correction  is  that  the 
alveolar  process  is  less  rigid  and  the  alveoli  larger  than  when  the  child 
is  older,  and  hence  less  resistance  is  offered.  At  the  age  mentioned  the 
deciduous  molars  are  firm,  and  in  some  cases  remain  so  until  the  child  is 
ten  or  twelve  years  of  age.  (See  page  712  and  following  pages  for  cases 
that  demand  early  treatment.)  At  an  early  age  new  tissue  is  built  up 
around  the  tooth  more  quickly,  as  the  osteoblasts  are  in  a  more  active 
condition;  hence  retaining  appliances  need  not  be  worn  so  long. 

Teeth  tend  to  more  into  their  proper  jxmtionH  if  room  is  made  for  them. 
This  seems  especially  true  of  the  canines.  In  many  cases  after  extrac- 
tion of  a  first  bicuspid  the  canine  will  move  to  its  place  without  assist- 
ance.    (See  Figs.  723  and  724.) 

Sufficient  explanation  should  be  made  to  the  child  to  overcome  any 
dread  or  fear  which  may  have  been  engendered. 


710 


ORTHODONTIA  AS  AN  OPERATIVE  PROCEDURE. 


'V\\v  parent  or  Liiiardiaii  should  sec  tliat  the  child  follows  the  opera- 
tor's directions  carcfnlly,  and  should  be  given  instructions  as  to  the 
course  to  pursue  in  case  any  appliances  become  dislodged.  Wiicn  screws 
are  used  an  intelligent  parent  or  guardian  may  assist  by  turning  them 
according  to  instructions.  If  the  ])aticnt  is  old  enough, and  desirous  of 
aiding,  he  may  be  intrusted  with  such  duties.  Screws  or  nuts  should  be 
given  about  half  a  turn  twice  a  da}-. 

Rul)ber  bands  shoidd  be  renewed  at  least  twice  a  week.  I'iano-wire 
springs  should  have  their  force  renewed  by  bending  (or  straightening), 
about  twice  a  week. 

Silk  or  linen  ligatures  should  be  renewed  daily  or  at  least  every 
other  dav.  They  should  be  well  waxed,  as  then  they  are  applied  more 
readily.  Moisture  soon  penetrates  the  wax  and  swells  the  fibers,  pro- 
ducing pressure  in  the  direction  intended. 

Wire  ligatures  should  be  twisted  daily  (Figs.  726  and  727). 

The  amount  of  force  which  may  be  used  will  vary  with  individuals. 
When  a  new  appliance  is  used,  no  force  should  be  applied  for  a  few 
days,  till  the  patient  becomes  accustomed  to  the  apparatus,  then  slight 
force  may  be  applied,  and  increased  after  a  few  days,  but  in  no  case 
should  excessive  force  be  used.  That  is,  in  no  case  should  force  be  used 
strong  enough  to  cause  continued  pain  or  loss  of  sleep,  nor  should  it 
make  the  teeth  "  tender  "  enough  to  prevent  mastication. 

Impressions  should  be  taken  of  the  teeth  of  both  jaws  in  all  but  very 


Angle's  impression  tray. 


simple  cases.  Trays  with  high  sides  and  flat  floor  should  be  used. 
Those  designed  by  Prof.  Angle  are  especially  adapted  to  the  purpose 
(Figs.  635  and  636). 

Modeling  compound   is   best   adapted    for   impressions  of  most 
cases.     It  should  be  placed  in  cold  water  and  slowly  heated  in  order  to 


GENERAL   DIRECTIONS. 


711 


soften  it  uniformly.  It  slioiikl  not  he  used  hot  enong-h  to  he  painful  to 
the  patient.  Warm  the  tray  hefore  fillino'  it  so  that  the  impression 
material  may  adhere  to  it  Avhen  it  is  removed  from  the  mouth.  AVhen 
the  compound  has  been  placed  in  the  moutli  and  pressed  against  the 
teeth,  draw  the  lip  over  the  edge  of  the  tray,  and  press  on  the  lip  so  as 

Fig.  636. 


Angle'.s  impression  tray. 


to  force  the  material  as  far  up  on  the  ridge  as  possible,  thus  obtaining 
an  impression  of  the  alveolar  walls. 

Special  cases  may  need  the  more  absolute  accuracy  of  plaster-of- 
Paris,  but  such  cases  are  rare. 

Avoid  an  excess  of  material  in  the  palatal  portion  of  the  tray,  as  the 
surplus  pressed  backward  is  apt  to  drag  at  the  necks  of  bicuspids  and 
molars.  When  the  material  has  been  pressed  into  correct  position, 
ajiply  cold  water  with  a  syringe  to  the  tray  and  under  the  lip  and 
cheeks  till  the  material  is  hard. 

Casts  made  from  these  impressions  should  be  articulated  either  with 
wire  hinges  or  by  extending  the  rear  portions,  and  preserved  for  fre- 
quent examination.  If  the  casts  are  held  together  by  a  ''  plaster  articu- 
lator," it  should  be  open  in  the  rear,  so  that  the  lingual  surfaces  and 
cusps  of  the  teeth  can  be  examined  w  hile  the  teeth  occlude.  An  extra 
east  will  often  be  needed,  on  which  to  make  ap])liances.  During  treat- 
ment, casts  should  be  made  at  interesting  stages  to  record  progress. 

Before  deciding  upon  treatment  study  the  case  in  action  and  repose; 
observe  the  movements  of  the  lips  in  speaking  and  laughing;  notice 
how  much  the  gums  are  disclosed,  if  at  all,  or  with  what  diilieultv  the 
teeth  are  covered  by  the  lips.     Study  the  profile.     If  the  irregularitv 


712  ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 

aifect  the  contour  of  the  lips,  have  a  photograph  taken  which  will  show 
the  ))rofile,  or  take  impressions  of  the  lips,  nose,  and  chin,  or  of  the 
whole  face,  with  plaster. 

Study  the  casts  also  before  deciding  on  the  treatment  or  ai)pliances. 
In  some  cases  make  an  extra  cast,  cut  oH'  the  mal posed  teeth  with  a 
thin  saw  and  re-arrange  them  in  normal  relationship.  Much  may  be 
learned  by  such  means. 

Classification  of  Irregularities. 

Aberrations  from  the  normal  arch  are  almost  numberless,  and  almost 
every  writer  adopts  a  different  nomenclature  to  express  the  malpositions 
that  he  wishes  to  describe. 

In  speaking  of  single  teeth,  it  seems  the  best  plan  to  describe  their 
positions  in  relation  to  the  normal  curve  or  arch  (Fig.  -599)  or  the  lines 
of  normal  eruption  (Fig.  600).  Thus,  a  tooth  erupted  within  the  normal 
arch  is  well  described  by  the  term  Ungual  ervption,  or  as  a  tooth  erupted 
lingually.  A  tooth  erupted  outside  the  normal  arch  is  well  described  by 
the  term  labial  eruption,  or  as  a  tooth  erupted  labially.  A  tooth  in  the 
normal  line,  but  turned  on  its  own  axis,  is  rotated. 

For  convenience  in  description,  irregularities  are  here  arranged  in 
fifteen  classes.  The  first  six  have  reference  to  single  teeth,  and  nearly 
all  the  rest  to  the  arches  as  a  whole  in  relation  to  each  other  and  to  the 
contour  and  profile  of  the  face. 

1.  Lingual  eruption  :  A  tooth  erupted  lingually. 

2.  Labial  eruption  :  A  tooth  erupted  labially. 

3.  A  tooth  rotated. 

4.  A  tooth  extruded. 

5.  A  tooth  partially  erupted. 

6.  Several  teeth  in  any  or  all  of  these  positions. 

7.  Prominent  canines  and  depressed  laterals. 

8.  Pointed  arch.     (V-shaped.) 

9.  Upper  protrusion. 

10.  LoAver  protrusion. 

11.  Double  protrusion. 

12.  Constricted  arch.     (Saddle-shaped.) 

13.  Lack  of  anterior  occlusion. 

14.  Excessive  overbite. 

15.  Separation  in  the  median  line. 

Class  1.  Ling-ual  Eruption  :  A  Tooth  Erupted  Lingually. — The 
operations  and  appliances  presented  for  the  first  four  classes  are  for  single 
teeth,  but  they  "will  apply  in  most  cases  to  two  or  more  teeth  in  the  same 
malposition.  In  Class  6,  appliances  will  be  described  which  are  better 
suited  to  several  teeth  than  to  single  ones. 


LINGUAL  ERUPTION. 


713 


The  earliest  cases  requiring  treatment  are  of  Class  1,  and  often  pre- 
sent as  early  as  the  age  of  six  or  seven  years,  and  before  the  tooth  has 
fully  erupted.  If  an  upper  central  has  erupted  inside  the  normal  line 
so  as  to  bite  inside  of  the  line  of  the  lower  incisors  when  it  is  not  more 
than  half  erupted,  the  case  demands  immediate  treatment,  because  the 
farther  the  tooth  erupts  the  greater  will  be  its  malposition,  for  it 
occludes  on  the  inclined  plane  formed  by  the  lingual  surface  of  the 
loAver  incisor. 

One  of  the  oldest  appliances  for  moving  a  tooth  forAvard  or  outward 
consists  of  a  vulcanite  plate  with  a  piece  of  soft  rubber  or  compressed 
wood  attached  to  the  edge  so  that  it  will  press  upon  the  malposed 


Fig.  637. 


Fig.  63: 


Plate  with  box,  a  ;  b,  rubber  or  compressed 
wood  iu  box. 


Rubber  tied  on  a  plate. 


tooth.     The  plate  may  be  ligated  firmly  to  the  deciduous  molars.     The 
soft  rubber  may  be  held  in  a  box  cut  in  the  edge  of  the  plate  (Fig. 


Fig.  639. 


Plate  with  gutta-percha  extension. 

637),  and  increased  in  thickness  as  the  tooth  advances,  or  a  piece  about 
J^  of  an  inch  thick  may  be  ligated  to  the  edge  by  silk  passing  through 
holes  near  by  (Fig.  638).     As  the  tooth  moves  forward  the  plate  may 


714 


ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 


Fig.  640. 


be  built  out  at  this  ])()iut  by  gutta-])crcha  filled  iuto  a  box  cut  in  the 
edtj^e  and  ])ress('d  at2:ainst  the  tooth  while  .still  sof"t.  Tiie  rubber  may  be 
ligated  on  the  outer  edue  of  the  gutta-percha,  which  may  be  increased 
in  amount  at  each  visit  (Fig.  639). 

The  I^X'LINED  pi.anp:,  as  illustrated  in  Fig.  640,  may  be  made  in 
various  forms.  It  is  on(»  of  the  oldest  forms  of 
regulating  appliances,  and  one  of  the  most  inef- 
ficient. It  depends  for  its  success  wholly  on  the 
co-operation  of  the  patient.  With  young  })atients 
its  use  is  not  as  successful  as  with  older.  The 
principle  is,  that  biting  on  the  inclined  plane 
slides  the  tooth  forward,  but  soon  the  biting  produces  inflammation  in 
the  pericemental  membrane,  a  "  soreness "  of  the  tooth  as  pojmlarly 
expressed,  when  every  bite  causes  pain  and  the  patient  naturally  refrains 
from  biting.  It  is  efficient  only  with  older  patients  who  exhibit  a  de- 
termination to  help  the  operation.  The  most  efficient  appliance  is  one 
which  does  not  depend  on  the  will  of  the  patient  for  its  action. 

Fig.  641  shows  a  very  efficient  appliance  used  by  Dr.  Matteson. 

Fig.  641. 


"Tube,  band,  and  spring"  appliance  (Matteson). 

With  young  patients  he  prefers  "  to  band  the  first  deciduous  and  first 
permanent  molars,  and  joining  these  bands  by  a  connecting  strip  on  the 
buccal  surface  and  a  piece  of  metal  tubing  closed  at  one  end  on  the 
palatal  surface."  A  piece  of  piano  wire  is  inserted  in  the  tube  and  the 
free  end  allowed  to  press  against  the  tooth  to  be  moved.  It  is  best  kept 
in  place  by  a  band  cemented  on  the  tooth  with  a  lug  or  half-section  of 
tubing  soldered  to  its  lingual  surface. 

If  the  band  is  made  as  recommended  by  Prof.  Angle,  by  drawing 
the  band  material  around  the  tooth  with  a  pair  of  pliers  and  soldering 
together  the  projecting  ends,  this  projecting  portion  may  be  left  long 
enough  so  that  a  notch  may  be  cut  in  it  for  the  piano  wire  to   rest  in. 

In  many  cases  of  the  age  under  consideration  the  second  deciduous 
molar  alone  will  be  firm  enough  to  be  banded  for  anchorage.     With 


LINGUAL  ERUPTION. 


715 


an  older  patient  whose  teeth  are  more  firmly  set,  a  bicuspid  or  first 

molar  alone  will  often  be  sufficient 

for  anchorage.  Fig.  642. 

For  short  teeth,  such  as  decidu- 
ous molars  or  partially  erupted 
bicuspids  or  molars.  Dr.  Matte- 
son  uses  swaged  caps,  made  with 
Mellotte's  moldine  and  fusible 
alloy,  so  as  to  fit  over  the  whole 
crown  and  be  cemented  in  place. 
Two  or  more  teetli  may  be  in- 
cluded in  one  cap,  and  tubes  may 
be  soldered  on  either  side  for  the 
attachment  of  springs,  etc.  (See 
Fig.  627.) 

A  similar  use  of  the  piano-wire  spring,  but  retained  by  the  Jack- 
son crib,  is  shown  in  Fig.  642.  Fig.  647  shows  a  different  form  of 
crib.  Both  Matteson's  and  Jackson's  ajipliances  are  applicable  to  any 
of  the  six  anterior  teeth. 

A  jack-screw  with  the  flattened  end  resting  in  a  slot  in  a  band 
cemented  on  the  tooth  to  be   moved  and  the  other  end   soldered  to  a 


Crib  and  band  (Jackson). 


Fig.  643. 


^^  V  h  -"  \y' 


Angle's  jack-screw. 

band  on  a  second  bicuspid  or  first  molar  for  anchorage,  or  resting  in  a 
socket  in  said  band,  is  very  efficient  for  moving  a  tooth  outward,  but  is 
more  applicable  to  laterals  and  canines  than  centrals.  (See  Fig.  643.) 
Another  plan  of  retention  of  tlie  anchor  end  of  the  jack-screw  is  to 
slip  the  open  end  of  the  tube  over  a   pin  or  lug  jn'ojecting  from  tlie 


716 


ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 


niolnr  hand.  The  luc^  may  be  easily  made  by  properly  shaping  the 
projeeting  ends  left  after  soldering  the  band.  The  teeth  selected 
for  an(;h()rage  should  be  as  nearly  as  possibk'  in  line  with  the  move- 
ment desired,  and  it  is  best  in  many  cases  to  solder  a  bar  on  the  lingual 
surface  of  the  anchor  band,  so  that  it  will  rest  on  contiguous  teeth  and 
thus  increase  the  power  of  resistance. 

Fig.  644. 


,.  .vjiai' 

Talbot's  spring  with  bands. 

Fig.  644  shows  Dr.  Talbot's  coiled  spring,  with  one  end  inserted  in 
a  small  socket  soldered  to  an  anchor  band  on  a  molar  and  the  other  in 
a  socket  on  a  band  on  the  lateral.     If  the  bands  are  thickened  on  one 


Fig.  645. 


Plate  and  coil  spring  for  moving  canine. 

side,  holes  may  be  punched  for  the  reception  of  the  ends  of  the  spring. 
Piano  wire  may  be  anchored  in  a  plate  so  as  to  force  a  tooth  outward. 
(See  Fig.  634.) 

In  some  cases  the  lower  incisors  impinge  so  closely  upon  the  necks 
of  the  upper  as  to  leave  no  room  for  appliances  unless  the  bite  is 
opened,  which  is  seldom  necessary. 


LINGUAL  ERUPTION. 


Ill 


Pi.ATE  AxcHOEAGE. — The  Canine  is  such  a  difficult  tooth  to  move 
that  very  firm  anchorage  is  necessary.  A  plate  constructed  so  as  to 
cover  the  crowns  of  the  bicuspids  and  molars  will  anchor  all  the 
teeth  together  and  give  plenty  of  resistance  to  a  spring  inserted  as 
in  Fig.  645  and  pressing  against  the  tooth  to  be  moved.  The  end 
of  the  spring  may  rest  in  a  hole  or  socket  in  a  band  cemented  to 
the  tooth. 
■  Fig.  646  shows  an  appliance  operating  outside  the  arch.      A  baud 

Fig.  646. 


Writer's  appliance,  close  bite  :  band  and  outside  spring. 

cemented  on  the  first  molar  with  a  tube  on  its  buccal  surface  forms  the 
anchorage.  In  this  tube  is  inserted  a  piano  wire,  which  is  bent  to  con- 
form to  the  arch  of  the  teeth  and  its  free  end  inserted  in  a  tube  or  hook 
on  the  labial  surface  of  a  band  cemented  on  the  tooth  to  be  moved. 
It  may  be  applied  to  any  of  the  six  anterior  teeth.  If  applied  to  a 
central  or  lateral  the  wire  may  rest  on  the  cuspid  as  a  fulcrum,  which 
gives  it  greater  power. 

The  Jack.S(m  crib  may  be  used  for  anchorage  instead  of  the  band 
and  tube,  as  shown  in  Fig.  647. 

A  bicuspid  is  easily  moved  out  into  line  by  the  appliance  shown  in 
Fig.  648.  The  screw,  which  passes  through  a  bar  about  \  of  an  inch 
wide,  soldered  to  a  band  on  a  convenient  tooth,  may  be  cut  off  as  the 
tooth  is  moved  out.     The  same  appliance  may  be  used  as  a  retainer. 

The  ap]>liance  shown  in  Fig.  649  is  highly  recommended  by  Dr. 
Talbot,  and  described  by  him  as  follows  :  It  is  made  of  German  silver, 
which  possesses  all  the  requisite  (jualities.  He  has  three  thicknesses  of 
it  ready  for  use,  Xos.  29,  31,  and  32,  U.  S.  gauge.  Strips  are  cut  Jg  to 
X  of  an  inch  wide  accordingly  as  strength  is  required,  and  bent  with 
small  round-nosed  pliers  into  the  shape  represented  at  a  to  fit  the  teeth. 
This  is  removed  every  day  and  with  round-nosed  pliers  the  ends  are 


718  ORTIIODOyriA   as  an  OrKRATIVE  PROCEDURE. 

bent,  and  tlie  spring  sliortencd  and  forced  to  place  ii])on  the  teeth.    The 


Fig.  G47. 


Fig.  648. 


Crib,  spring,  and  band  (Jackson) 


Bar,  band,  and  screw. 


little  spring  acts  in  two  directions — first,  to  carry  the  teeth  laterally 
and  thus  provide  room ;  secondly,  to  draw  the  irregular  teeth  into 
position.  In  the  hands  of  the  writer  this  has  been  a  very  efficient 
appliance. 

Fig.  649. 


German-silver  spring  (Talbot). 

Making  Room. — If  the  adjacent  teeth  overlap  the  one  out  of  posi- 
tion it  is  best  to  make  room  before  attempting  to  move  it,  because  it 
cannot  advance  until  room  is  made  for  it,  and  force  spent  on  it  will  be 
of  no  avail  unless  the  tooth  acts  as  a  wedge  to  force  the  others  a]:)art. 
A  piece  of  compressed  wood,  one  of  the  oldest  forces  used  in  ortho- 
dontia, can  be  used  in  many  cases  as  shown  at  a,  Fig.  650.  Cut  a  piece 
of  wood  about  a  third  larger  than  the  space,  compress  it  with  pliers  or 
the  vise,  and  insert  it  with  the  grain  parallel  to  the  axis  of  the  teeth. 
If  the  sides  are  made  slightly  concave,  it  will  hold  in  place  better.  As 
the  w^ood  absorbs  moisture  it  will  swell  and  press  the  teeth  apart. 


LINGUAL  ERUPTION. 


719 


A  better  method  of  gaining  room  is  to  cement  bands  on  the  two 
adjacent  teeth  with  tubes  on  the  labial  surfaces.  In  these  tubes  insert 
a  Matteson  spring,  as  shown  in  Fig.  651.     As  soon  as  sufficient  room 


Fici.  650. 


Fig.  651. 


Compressed  wood  fur  making  room. 


^Jatteson  spring  applied  to  bands. 


is  gained,  a  straight  wire  may  be  inserted  in  the  tubes  across  the  space. 
A  rubber  band  stretched  over  the  malposed  tooth  from  this  wire  will 
soon  move  it  into  place. 

Fig.  652  shows  a  very  satisfactory  modification  of  the  above  appli- 
ance, using  intermittent  force  instead  of  constant.     A  screw  with  two 

Fig.  652. 


Writer's  appliance  fur  making  room  and  moving  touth  out. 

nuts  on  it,  or  one  collar  and  one  nut,  is  inserted  in  the  tubes,  and  the 
nuts  screwed  against  the  tubes.  If  one  of  the  nuts  is  turned  two  or 
three  times  a  day,  the  teeth  will  soon  be  moved  apart.  The  nuts  will 
hold  the  teeth  apart  while  a  rubber  band  or  ligature  passed  over  the 
screw  and  the  maljwsed  tooth  will  soon  draw  it  forward,  or  if  the  rubber 
band  is  applied  while  the  contiguous  teeth  are  being  spread  apart,  the 
tooth  will  move  forward  as  room  is  made  for  it. 

Retainer. — The  l)est  retainer  for  a  single  tooth  moved  forward 
consists  of  a  Magill  baml  with  a  round  wire  soldered  on  its  labial  sur- 
face.    (See  Fig.  653.)     A    muud  wire  is  better  than  a  flat  bar,  because 


720 


ORTHODONTIA  AS  AN  OPERATIVE  PROCEDURE. 


it  rests  on  the  tootli  at  one  point  only  and  tliere  is  less  liability  of"  food 
lodging  under  it,  as  illustrated  in  Fig.  Grj4. 


Fig.  653. 


Fk;.  654. 


Writer's  retainer  band  and  round 
wire. 


Round  and  thit  contacts 
in  regulating  lixtures. 


When  a  band  is  to  be  used  as  part  of  an  appliance  fen*  moving  a 
tooth  into  place,  as  in  Fig.  643,  a»tubc  can  be  soldered  to  its  anterior 


Fig.  655. 


I'roviding  in  advance  for  retention  (Angle). 


surface.     After  the  tooth  is  moved  into  position  this  same  band  may 
be  u.sed  as  a  retainer  by  passing  a  wire  through  the  tube  so  that  its 


Fig.  656. 


Fig.  657 


Angle's  retainer. 


Talbot's  retainer. 


ends  will  rest  on  adjacent  teeth.     This  wire  can  be  fastened  in  the  tube 
with  cement,     (See  Figs.  655,  656,  and  657.) 

Class  2.  Labial  Eruption :  A  Tooth  Erupted  Labially. — The  sim- 
plest method  of  moving  such  a  tooth  backward  is  by  a  rubber  band  or 
ligature  looped  over  one  tooth  on  each  side  of  the  prominent  one,  and 
passing  over  its  labial  surface.  (See  Fig.  658.)  Although  this  is  effec- 
tive in  simple  cases  there  is  the  theoretical  objection  that  the  rubber 
band  or  ligature  tends  to  draw  the  contiguous  teeth  tow^ard  the  promi- 


LABIAL   ERUPTION. 


721 


nent  one  and  thus  to  impede  the  very  movement  desired.  One  practical 
objection  is  that  the  rubber  band  tends  to  rotate  the  teeth  over  which 
it  is  looped.  Tlie  rubber  band  may  be  ligated  to  the  second  tooth  on 
each  side  and  passed  under  the  first. 


Fig.  658. 


Rubber  band  and  ligature. 


The  next  simplest  method  is  the  strip  of  elastic  German  silver  as 
described  by  Dr.  Talbot — ^just  the  reverse  of  that  shown  in  Fig.  649. 

One  of  the  oldest  appliances  and  an  excellent  one  is  shown  in  Fig. 
659.     It  consists  of  a  plate  fitting  the  roof  of  the  mouth,  held  by  atmos- 


FiG.  659. 


Plate  and  rubber  band. 

pheric  pressure  in  contact  with  the  lingual  surfaces  of  the  teeth  except 
w'ith  that  of  the  prominent  one.  A  rubber  band  stretched  over  this 
tooth  is  attached  to  the  plate  at  some  point  directly  in  line  with  the 
movement  desired,  and  far  enough  from  the  tooth  to  give  the  desired 
amount  of  force.  For  attachment  a  hook  may  be  vulcanized,  or  a  hole 
drilled  in  the  plate  at  an  acute  angle,  and  a  wooden  peg  inserted,  which 
is  kept  tight  by  swelling.  Another  simple  way  to  attach  the  rubber 
band  is  to  drill  two  holes  through  the  plate  and  tie  with  thread.  This 
46 


722 


ORTHODONTIA    AS  AN  OPERATIVE  PROCEDURE 


has  one  advantage,  that  the  patient  may  be  allowed  to  remove  the  plate 
for  cleansing  -without  danger  of  losing  the  rubber  band. 

If  the  adjacent  teeth   need  to  be  moved  apart  to  make  room    the 

rubber  band  may  be  fastened  to  the 
^^'  ^^  '  plate  at  two  j)oints,  as  shown  by  the 

dotted  lines  in  Fig.  059,  or  farther 
apart,  so  as  to  jiress  laterally  as 
well  as  backward. 

The  plate  may  be  ligated  to  teeth 

on  each  side  of  the  mouth  to  hold  it 

"V'^y^z/f/'^  '^ ■"'*'"  ■       more  securely,  and  a  silk   or  linen 

ligature  may  be  substituted  for  the 

rubber  band. 

Fig.  660  shows  Dr.  Talbot's  plan  of  gaining  room  by  means  of  a 
coiled  spring  with  the  ends  resting  on  the  teeth  to  be  spread  apart. 

The  plate  may  be  dispensed  with  by  cementing  a  band,  to  which  a 
hook  has  been  soldered,  on  some  tooth  in  line  with  the  movement  de- 
sired, and  stretching  a  rubber  band  from  the  prominent  tooth  over  this 
hook.  The  anchorage  may  be  increased  by  a  wire  or  bar  soldered  to  the 
outside  of  the  band  so  as  to  rest  on  contiguous  teeth.     (See  Fig.  661.) 

Fig.  661. 


Talbot's  spring  with  bands,  for  making  room. 


Band  and  bar  fur  anchorage;  rubber  band  for  drawing  tootli  in  (Guilford). 

In  order  to  apply  the  force  in  the  proper  direction  in  moving  a  cen- 
tral incisor,  it  may  be  necessary  to  use  a  tooth  on  each  side  of  the  mouth 
for  anchorage,  in  which  case  it  is  better  to  extend  a  rubber  band  from 
each  anchor  tooth  to  a  hook  on  the  lingual  surface  of  a  band  on  the 
central.     (See  Fig.  662.) 

The  occlusion  may  be  such  that  the  cutting  edges  of  the  lower  in- 
cisors nearly  or  quite  touch  the  necks  of  the  upper  or  the  gum,  and 
thus  prevent  the  use  of  any  appliance  on  the  lingual  surfaces  of  the 
teeth  without  opening  the  bite,  which  it  is  best  to  avoid  if  possible.  In 
such  cases  (see  Fig.  663)  cement  a  band  on  a  bicuspid  or  first  molar  on 


LABIAL   ERUPTION. 


723 


each   side,  Mitli  a  tube  on  the  buccal  surface.     Through  these  tubes 
around  the   arch,  and   in   contact  with  the  prominent   tooth,  extend  a 


Fig.  662. 


Double  anchorage  for  elastic  traction. 


labial  bow  of  stiff  wire,  Xo.  16  B.  &  S.  gauge,  screw-cut  at  the  ends. 
Place  nuts  on  the  ends  of  the  bow  spring  behind  the  tubes.     By  turn- 


FiG.  663. 


Labial  tmw  fur  drawiiiLT  tnoth  in. 

ing  the  nuts  pressure  i.>^  brought  to  boar  on  the  prominent  tooth.  To 
prevent  the  wire  sliding  on  the  surface  of  the  tooth,  cement  on  it  a 
band  on  which  is  soldered  a  lug  or  a  half-section  of  tubing  in  which 
the  wire  can  rest ;  or  u.'^e  Angle's  notched  band.  (See  Fig.  771.)  If 
elastic  wire,  such  as  platinum-gold  or  German-silver  wire,  drawn  hard, 
is  used,  constant  force  can  be  applied,  as,  when  the  nuts  are  turned,  the 
wire  will  be  l)cnt  and  in  its  tendency  to  straighten  will  press  on  the 
tooth. 

Fig.  664  shows  an  appliance  wiiieh  may  be  used  with  much  satisfac- 
tion.    In  this  case  the  first   molar  has  been  previously  extracted.     Tiie 


724 


ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 


line  between  the  central  incisors  is  to  the  riglit  of  the  niechan  hnc  of  the 
face.  The  bicuspids  are  to  be  pushed  back  and  the  incisors  toward  the  left 
at  tiie  same  time.  The  appliance  works  on  the  principle  of  two  wedges 
drawn  toward  each  other.  On  the  canine  is  cemented  a  band  with  a 
short  tube  on  its  lingual  surface.  In  this  tube  is  placed  one  of  Angle's 
short  drag-screws,  while  the  other  passes  through  a  strip  of  metal  about 


Writer's  appliance  for  making  room  and  drawing  cuspid  in. 

\  of  an  inch  wide  which  rests  on  the  first  bicuspid  and  the  lateral. 
This  strip  is  bent  so  as  to  form  one  wedge  while  the  canine  serves  as 
another.  The  nut  on  the  end  of  the  screw  draws  the  two  wedges,  that 
is,  the  canine  and  the  strip,  toward  each  other  and  spreads  the  lateral 
and  bicuspid  from  one  another.  The  strip  is  altered  in  form  as  the 
work  progresses — always,  however,  retaining  its  wedge  shape.  The 
same  appliance  may  be  worn  as  a  retainer  after  the  canine  is  in 
place. 

Class  3.  Rotated  Teeth. — \Yhile  attachment  may  be  made  to  a 
tooth  for  rotating  it  by  ligatures  (a  modification  of  the  clove  hitch)  or 
by  drilling  pits  in  which  are  inserted  screws  or  pins  secured  by  cement, 
the  first  of  these  serves  only  a  temporary  purpose,  and  the  second 
mutilates  the  tooth  more  than  is  warrantable  except  in  extreme  cases. 

For  the  incisors  the  best  attachment  is  a  Magill  band  not  thicker 
than  No.  36  B.  &  S.  gauge,  to  which  is  soldered  a  hook,  pin,  or  tube. 
For  the  canines  a  swaged  cap  is  better,  as  it  may  be  cemented  more 
firmly  in  place. 

To  rotate  an  incisor  which  overlaps  the  adjacent  tooth,  cement  a 
band  on  the  tooth  with  a  hook  on  either  the  labial  or  the  lingual  surface. 
From  this  hook  extend  a  rubber  band  or  ligature  to  a  vulcanite  plate 
held  by  atmospheric  pressure.  Secure  the  rubber  band  to  the  plate  by 
ligating  through  two  holes.  (See  Fig.  665.)  The  plate  should  be  cut 
away  slightly  as  the  tooth  rotates.  The  point  of  the  attachment  to  the 
plate  will  vary  according  to  the  direction  of  force  needed.  By  attach- 
ing at  C,  Fig.  712,  room  may  be  gained  by  attaching  the  rubber  band 
so  that  it  will  press  against  the  adjacent  tooth,  over  which  the  otfending 
one  may  be  lapped. 


ROTATED  TEETH. 


725 


The  plate  may  be  di.speused  with  by  attaching  the  rubber  band  to 

some  other  tooth  for  anchorage 
(Fig.  6Q()),  or  to  a  lingual  bow 
as  shown  in  Fig.  667. 

Fig.  666. 


Plate  and  band  for  rotating 


Two  Magill  bands  for  rotating. 


Extra  force  may  be  gained  in  rotating  by  passing  the  rubber  once 
around  the  tooth  after  attaching  it  to  the  hook,  as  a  rope  is  wound 
around  a  windlass. 

If  it  be  necessary  to  rotate  a  tooth  outwardly,  attach  bands  with 
tubes  to  any  two  convenient  teeth  such  as  canines  or  bicuspids ;  extend 

Fig.  G67. 


Writer's  lingual  bow  and  hook  band  for  rotation. 

a  wire  bow  from  one  to  the  other,  as  in  Fig.  668,  and  use  this  as  a  point 
of  attachment  for  the  rubber  band.  The  ends  of  the  bow  are  prevented 
from  passing  too  far  through  the  tubes  by  the  bending  in  bayonet  shape 
or  by  pinching  the  posterior  ends  of  the  tubes.  If  the  canines  are  used 
for  anchorage,  solder  the  tubes  vertically  to  the  bands  and  bend  the 
ends  of  the  bow  at  right  angles. 

Force  may  be  applied  to  the  tooth  from  two  directions  by  making 
hooks  on  both  sides  of  the  band  and  extending  a  rubber  band  or  ligature 
from  one  hook  to  a  labial  bow  and  from  the  other  to  the  lingual  bow,  as 
shown  in  Fig.  669,  A  and  /;. 


726 


ORTHODONTIA   AS' AN  OPERATIVE  PROCEDURE. 
Fig.  668. 


Ijiibial  bow  and  hook  band  for  rotation. 


In  many  cases  another  tooth  which  needs  rotating  may  be  used  for 
anchorage,  and  thus  double  rotation  is  accomplished,  either  in  the  same 


Fig.  669. 


""fe^-' 


^^\^ 


A,  Rubber  band  from  lingual  hook  to  labial  bow  ;  B,  from  hibial  hook  to  lingual  bow. 

or   opposite   directions.     A  study  of  the  ilUistrations  Figs.   670-673 
will  show  the  student  how  the  diiferent  movements  are  accomplished. 


Fig.  670. 


Fig.  671. 


Fig.  673. 


Bandage  for  double  rotation. 


ROTATED   TEETH. 


727 


In  many  cases  a  tooth  may  be  moved  out  of  or  into  the  normal  line  and 
rotated  at  the  same  time  by  applying  the  force  to  a  hook  on  a  band. 
Where  a  jack-screw  is  used  it  can  be  applied  at  the  mesial  or  distal 
portion  of  the  tooth  as  needed.     (See  Fig.  ()74.) 


Fig.  674. 


Fig.  676. 


Angle's  jack-screw  for  moving  tooth  outward  and 
rotating. 

Fig.  675  shows  one  of  Prof.  Angle's 
methods,  which  he  describes  as  follows: 

Fm.  675. 


Angle's  pinched  wire  for  extension  and  rotation. 

"•  The  tooth   was  banded  and   one  of 

the  pipes  soldered  to  tlie  mesio-lingual 

Fig.  677. 


Retainer. 


gle's  pliers  for  pinching  wire. 


angle  of  the  l)and  ;  one  end  of  a  ])icce  of  wire  of  suitable  length  was 
inserted  into  this  pipe  and  the  other  end  secured  in  a  pit  formed  in  the 


728 


ORTHODONTIA    AS  AN   OPERATIVE  PROCEDURE. 


onaiiiel  of  the  second  decitliions  molar.  Force  was  exerted  upon  the 
tooth  to  be  nioNxnl  by  occasionally  pinching  this  wire  with  the  regu- 
lating pliers  (Fig.  676),  two  or  three  pinches  being  enough  to  lengthen 
the  wire  sufficiently  to  move  the  tooth  as  far  as  should  hv  done  at  one 
sitting. 

"The  simplest  retainer  is  a  band  with  a  short  piece  of  round  wire 
soldered  to  it,  so  that  it  will  impinge  upon  the  adjacent  tooth.  It  is 
necessary  sometimes  to  fasten  such  a  lug  on  each  side  of  the  band." 
(See  Fig.  677.) 

When  double  rotation  has  been  accomplished,  the  teeth  may  be 
retained  by  soldering  the  bands  together  at  the  points  of  contact. 

Angle's  appliance  for  double  rotation  is  easily  understood  from  an 
examination  of  Figs.  678  and  679.  The  piano-wire  spring  should  not 
be  larger  than  No.  24  B.  &  S.  gauge. 


Fig.  GTS. 


Fig.  679. 


Angle's  appliance  for  double  rotation. 

Although  this  appliance  is  very  effective,  two  difficulties  attend  its 
use.     Sometimes  the  spring  fails  to  slide  through  the  tubes  as  the  teeth 


Fig.  680. 


Fig.  681. 


Guilforcr.s  lever  for  rotating. 


Angle's  detaclialile  lever  for  rotating. 


rotate  and  the  teeth  are  spread  slightly  apart.     This  tendency  can  be 
obviated  by  tying  a  silk  ligature  from  one  tube  to  the  other. 

Sometimes  the  distal  surfaces  of  the  teeth  will  turn  forward,  so  that 
they  will  stand  wholly  out  of  the  line  of  the  other  teeth.  This  can  be 
prevented  by  soldering  lugs  on  the  lingual  surfaces  of  the  bands,  to  rest 
on  the  laterals.  In  some  cases,  as  the  centrals  turn,  these  lugs  will 
slide  on  the  inclined  plane  formed  by  the  lingual  surfaces  of  the  laterals 


EXTRUSION. 


729 


Fig.  682. 


and  either  push  the  laterals  up  iu  the  socket  or  elongate  the  centrals. 
This  may  be  prevented  by  bands  on  the  laterals  with  a  projection  on 
each,  under  which  the  lugs  will  rest  and  be  prevented  from  moving. 

Another  method  of  rotating  is  bv  means  of  a  lever  attached  to  a  band 
on  the  tooth  as  shown  in  Fig.  680.  The  end  of  the  lever  is  bent  in  the 
form  of  a  hook,  from  which  a  rubber  baud  passes  over  some  convenient 
tooth.  Prof.  Angle  has  made  the  lever  detachable  (Fig.  681)  by  solder- 
ing a  tube  to  the  band  and  inserting  in  it  a  piece  of  piano  wire.  The 
other  end  of  the  wire  is  bent  in  the  form  of  a  hook  and  ligated  to  some 
convenient  tooth,  or  placed  under  a  hook  soldered  to  a  baud  on  such 
tooth. 

Fig.  682  shows  Dr.  Matteson's  swaged  cap  on  a  deciduous  molar, 
with  a  hook  for  this  purpose.  In 
using  the  lever  special  care  must  be 
taken  not  to  let  it  rest  on  any  tooth 
between  the  anchorage  and  the  of- 
fending tooth,  otherwise  it  will  move 
the  tooth  out  of  line. 

Class  4.  Extrusion,  or  a  Tooth 
Extruded. — The  simplest  treatment 
for  a  tooth  that  is  extruded  is  to 
grind  it  shorter.  As  grinding  alters 
the  natural  shape  of  the  tooth  in 
proportion  to  its  extent,  other  means 
are  sometimes  necessary. 

A  tooth  sometimes  elongates,  in 
regulating,  by  the  carelessness  of  the  patient  or  operator,  or  by  unfore- 
seen complications.  In  such  a  case  an  immediate,  even  though  tem- 
porary, appliance  is  necessary.  Tie  a  ligature  around  the  necks  of  the 
adjacent  teeth  with  the  knots  between  each  and  the  oifending  tooth. 
Extend  one  end  of  each  ligature  lingually  and  one  labially.  (See  Fig. 


Mattusiiu's  swaged  cap  for  anchorage. 


ri(i.oy:j. 


Writer's  plan  for  reducing  extruded  teeth. 


683.)     Tie  the  lingual  end.-^  together  behind  the  long  tooth,  and  in  the 
same  knot  tie  a  slender  rubber  band.     (See  Fig.  684.)     Tie  the  labial 


30 


OliTIIODOyriA  AS  Ay   OriniATlVE  rilOCEDURE. 


ends  toijethcr  in  front  of  the  long  tooth.     Next  stretch  the  rubber  band, 
from   the  lingual  surface  of  the  neck,  over  the  cutting  edge,  and  tie  it 


Fig.  684. 


Fig.  085. 


i4  '' 

Writer's  plan  for  reducnn^  extruded  teeth. 

to  the  knot  on  the   labial  surface.  (See  Fig.  685.)     The  tooth  is  thus 
hung  in   a  sling  whicli   will  force  it  up  into  place. 

Another  simple  plan   is  that  suggested  by  Dr.  William  Herbst  for 
retaining  a  replanted  tooth.     It  is  shown  in  Fig.  687.     It  consists  in 


Fig.  686. 


Fig.  687. 


Herbst  method  of  reduction  and  retention. 

cutting  a  short  and  narrow  strip  from  a  piece  of  rubber  dam  (Fig.  686) 
and  perforating  it  in  such  a  manner  that  when  in  position  the  crowns 
of  two  teeth  on  either  side  of  the  one  affected  will  protrude  through  the 
openings  while  the  elongated  tooth  will  be  partly  covered  and  pressed 
upon  by  the  intervening  portion  of  the  rubl)er.     (See  Fig.  687.) 

Fig.  688. 


Appliance  for  reducing  extrusion. 


A  better  plan  is  to  band  one  tooth  on  each  side  and  connect  the 
bands  on  both  labial  and  lingual  surfaces  by  a  wire  soldered  to  both 
bands,  or  resting  in  tubes  soldered  to  the  bands  (Fig.  688),  or  soldered 
to  one  band  and  restino^  in  a  hook  on  the  other.  A  twisted  limiture  or 
slender  rubber  band  stretched  from  the  lingual  to  the  labial  wire,  over 
the  cutting  edge  of  the  hmg  tooth,  will  soon  force  it  up.  (See  Fig.  689.) 
A  small  cap  with  a  notch  in  it  may  be  cemented  to  the  end  of  the  long 


PA  E  TIA  L  ER  UP  T ION. 


731 


tooth,  to  prevent  the  rubl)er  band  from  slipping  off.    When  the  tooth  is 
moved  to  its  desired  position  it  may  be  retained  by  substituting  a  small 


Fig.  689. 


Fig.  690. 


Writer's  appliance  for  reducing  extrusion. 


Details  of  appliance  shown  in  Fig.  689. 


platinum  wire  or  silver  suture  ^\•ire  for  the  rubber  band,  or  three  bands 
may  be  soldered  together  and  cemented  to  the  teeth. 

Class  5.  Partial  Eruption. — A  tooth  may  need  elevating  because 
it  has  not  fully  erupted  or  because  a  piece  has  been  broken  from  the 
cutting  edge.  If  the  short  tooth  is  an  incisor,  proceed  as  follows  :  On 
the  adjacent  teeth  cement  bands  or  caps  which  are  connected  bv  a  wire 
at  or  near  the  cutting  edge.     On  the  short  tooth,  as  near  the  gum  as 

Fig.  691. 


Writer's  method  of  elevating. 

possible,  cement  a  wide  band  which  has  a  hook  or  pin  on  both  labial 
and  lingual  surfaces.  From  one  hook  stretch  a  very  slender  rubber 
band  or  tM'isted  ligature  over  the  wire  to  the  other  hook.  (See  Fig.  691.) 
Less  force  is  required  for  elevating  a  tooth  than  for  any  other  move- 
ment, as  a  conical  root  is  drawn  from  a  conical  socket,  and  care  must 
be  taken  not  to  move  the  tooth  too  rapidly  lest  the  pulp  be  ruptured 
at  the  apical  foramen  or  the  peridental  membrane  be  ruptured.  If 
the  wire  is  soldered  on  the  cutting  edges  of  the  caps,  it  will  prevent 
the  possibility  of  drawing  the  tooth  too  far.  For  retention  substitute 
a  small  platinum  or  silver  suture  wire  for  the  rubber  band,  or  apply 
three  bands  soldered  together.  A  broken  tooth  may  be  elevated  by 
means  of  the  same  kind  of  ap])liance  (see  Fig.  692),  and  then  the  cut- 
ting edge  ground  to  conform  to  the  other  teeth. 

For  a  partially  erupted  canine  an  excellent  plan  is  that  of  Prof. 
Angle,  shown  in  Fig.  693. 


732 


ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 


AVhere  the  canine  has  not  erupted  far  enon<i;h  for  cementing  a  band 
or  swaged  cap  on  it,  a  small  hole  may  be  drilled  in  the  tooth,  in  which 


Fig.  692. 


Writer's  method  of  elevating  broken  tooth. 

a  small  screw  or  pin  is  secnred  by  cement.  This  may  be  afterward 
filled  with  gold,  or  with  a  piece  of  a  small  glass  rod,  as  described  by 
Prof.  L.  L.  Dunbar.^ 

In  some  cases  it  is  advantageous  to  use  teeth  of  the  lower  jaw  for 
anchorage,  as  shown  in  Fig.  694. 

The  patient  may  remove  the  rubber  band  from  the  upper  tooth  while 
eating.     As  rubber  bands  are  liable  to  be  broken  by  a  too   sudden 

Fig.  693.  Fig.  694. 

\     ... 


Angle's  method  of  forcible  eruption. 


Angle's  method  of  using  the  lower  jaw  for 
anchorage. 


opening  of  the  patient's  mouth,  it  is  well  to  attach  two  or  three  to  the 
lower  tooth,  as  a  reserve  in  case  one  is  broken  between  visits  of  the 
patient.  The  lower  metal  band  may  be  dispensed  with  by  ligating  the 
rubber  band  to  the  neck  of  the  tooth.  As  the  rubljer  band  tends  to 
draw  the  ligature  away  from  the  gum,  inflammation  is  not  likely  to 
ensue  as  in  many  other  uses  of  such  a  ligature. 

Figs.  695  and  696  show  how  this  plan  has  been  successfully  applied 
by  the  writer  for  elevating  bicuspids  and  molars  which  do  not  occlude. 
Bands  with  hooks  are  attached  to  both  upj^er  and  lower  teeth  and  a 
rubber  band  stretched  from  each  upper  hook  to  a  corresponding  lower 
one,  or  the  place  of  either  upper  or  lower  l)and  is  supplied  by  a  liga- 
^  Pacific  Coast  Dentist,  vol.  i.  p.  14. 


PARTIAL  ERUPTION. 


733 


ture.     The  teeth,  being  drawn  out  of  their  sockets  toward  each  other, 
will  soon  meet  and  adapt  their  occlusal  surfaces  to  each  other.     This 


Fig.  695. 


Writer's  plan  of  occluding  bicuspids  and  molars. 

adaptation  may  be  assisted  by  grinding  or  re-shaping  any  cusps  that 
may  be  an  obstruction.     The  case  shown  in  Fig.  696  was  treated  in 

Fig.  696. 


Uesturation  of  occlusion. 


the  infirmary  of  the  Dental  Department  of  the  University  of  Califor- 
nia by  a  senior  student  under  the  writer's  directions.  An  unexpected 
result  was  also  obtained.     The  upper  arch  was  much  narrower  than  the 


Fig.  697 


Labial  b 


uiid  ileiTC'ssinK  canines. 


lower.     The  upper  teeth  were  drawn  outward  as  well  as  downward  and 
the  arch  was  widened. 

The   following  case  will   serve  to  illustrate   reciprocal   movement : 


734 


ORTHODONTIA   AS  AN  OPERATIVE  RROCEDURE. 


The  central  iiioisor.s  of  a  patient  about  twenty  years  of  age  were  par- 
tially denuded  of  enamel  for  about  Jg-  of  an  inch  from  the  cutting  edge. 
The  lateral  incisors  had  the  same  defect  at  the  cutting  edge  only.  It 
was  thought  best  to  elevate  the  central  incisors,  and  grind  off  the  por- 
tion denuded  of  enamel.  Bands  were  fitted  to  the  centrals  (Fig.  697) 
>vith  hooks  on  their  labial  surfaces  pointing  upward,  also  on  the  canines 

Fk;.  698. 


Labial  bow  for  ix'tention. 

with  hooks  pointing  downward,  and  on  the  second  bicuspids  with  tubes 
on  their  buccal  surfaces.  A  wire  bow  was  extended  from  the  tube  on 
the  left  bicuspid  to  the  tube  on  the  right,  and  caught  under  the  hooks 
on  the  canines.  Slender  rubber  bands  were  then  stretched  from  the 
wire  over  the  hooks  on  the  centrals,  and  soon  elevated  them  sufficiently 
to  grind  off  the  denuded  portion.  The  same  appliance  was  used  as  a 
retainer  by  bending  the  bow  wire  upward  slightly  and  hooking  it  over 
the  hooks  on  the  incisors. 

The    elevation  of  a  l^roken    upper  incisor  is  sometimes    interfered 
with  by  occlusion  of  the  lower  incisors  on  the  slanting  lingual  surface 

Fig.  699. 


Flattening  lower  arch  with  labial  bow. 

SO  that  it  is  necessarv  to  shorten  the  lower  incisors  bv  orrindincr.  In 
some  cases  it  is  warrantable  to  grind  away  the  upper  incisor  on  the 
lingual  surface,  where  too  much  grinding  of  the  lower  teeth  would  mar 
their  appearance.  In  the  case  just  described  it  was  necessary  to  press 
the  lower  incisors  back  by  flattening  the  arch  as  shown  in  Fig.  699. 
The  following  case  of  forcible  eru])tion  may  be  instructive : 
Miss  R.  W.,  aged  eighteen,  presented  herself  with  the  point  of  the 


PARTIAL  ERUPTION. 


735 


upper  left  canine  erupting  behind  the  lateral  incisor  while  the  deciduous 
canine  was  still  in  place.     The  cusp  had  penetrated  the  gum  abuut  a 


Fig.  700. 


Forcible  eruption  of  canine. 

year  before,  but  had  din*ing  that  time  made  no  progress  in  eruption. 
The  writer  decided  to  cause  the  tooth  to  erupt  forcibly,  by  means  of  a 
coiled  spring  as  suggested  by  Dr.  Talbot.  As  the  deciduous  canine  was 
large  and  firm  and  but  slightly  decayed,  it  was  thought  best  to  let  it 
remain  in  place  till  the  permanent  tooth  was  erupted  far  enough  to  see 
if  it  were  well  formed.     By  depressing  the  gum  slightly  a  hole  was 


-liuwiug  result  of  uperutiuu. 


drilled  in  the  enamel  in  the  lingual  surface  of  the  tooth.  In  this  hole 
was  inserted  one  end  of  a  coiled  spring,  which  was  attached  to  a  plate, 
as  shown  in  Fig.  700,  which  shows  the  cusp  emerging  from  the  gum. 
The  tooth  was  soon  eruj)tcd  to  its  normal  length,  when  the  deciduous 


736 


ORTHODONTIA  AS  AN  OPERATIVE  PROCEDURE. 


canine  was  extracted.  By  means  of  a  rubber  band  from  a  labial  bow, 
the  ends  of  which  rested  in  tubes  attached  to  bands  on  right  and  left 
bicuspids,  the  tooth  was  readily  brought  into  line  as  shown  in  Fig.  701. 


Fio.  702. 


Fig.  703. 


A  band-and-bar  retainer  (Fig.  653)  was  a])plied  to  keep  the  tooth  in 
place  till  it  became  firm. 

Tooth  Shaping. — The  operation  of  grinding  has  been  referred  to 
in  the  shortening  of  an  extruded  tooth,  and  also  for  re-shaping  a  tooth 
from  which  a  corner  has  been  broken  after  having  first  elevated  the 
tooth.  (See  Fig.  692.)  It  may  be  advantageously  employed  for  re- 
shaping teeth  which  have  been  left  longer  than  the  contiguous  ones  by 
the  wearing  away  of  the  latter,  as  shown  in  Figs.  702-705,  suggested 
by  Dr.  W.  S.  How.' 

In  many  instances  upper  incisors  are  worn  away  on  their  lingual 
surfaces,  leaving  thin  edges  of  labial  enamel  which  are  easily  broken 
away  irregularly.  (See  Fig.  706.)  These  broken  edges  may  be  re- 
moved and  the  teeth  improved  very  much  in  appearance  by  grinding. 

The  cusps  of  bicuspids  and   molars   sometimes   interfere   with   the 


Fig.  704. 


Fig.  705. 


Fig.  706. 


Worn  or  broken  teeth  (Farrar). 

desired  movement  of  an  antagonizing  tooth  and   may  be  reduced  by 
grinding  so  as  to  present  no  obstruction. 

Lower  canines  which  prevent  upper  canines  or  lateral  incisors  from 
moving  into  their  proper  position  may  have  the  apex  of  the  cusp  ground 
away,  and  in  some  cases  even  a  portion  of  the  labial  enamel  may  be  re- 
moved to  advantage.  An  incisor  which  inclines  toward  the  contiguous 
tooth  so  much  as  to  present  one  angle  lower  than  the  other  may  have 
this  corner  ground  away  so  as  to  present  the  cutting  edge  in  line  with 
the  other  teeth.  Fig.  707  shows  how  much  of  the  enamel  of  a  tooth 
may  be  removed  in  various  cases  without  exposing  the  dentin. 

^  Dental  Cosinos,  vol.  xxviii.  p.  741. 


PARTIAL  ERUPTION. 


737 


"Truing  up"  is  a  term  applied  by  Dr.  Farrar  to  the  process  of 
removing  overlapping  portions  of  teeth  so  that  they  will  present  a  nor- 
mal appearance.     (See  Figs.  708  and  709.) 

Much  discomfort  may  be  prevented  if  the  corundum  wheel  be 
held  as  in  Fig.  710,  as  the  tooth  is  supported  by  the  contiguous  ones 

Fig.  707. 


Showing  thickness  of  enamel  (Farrar). 

and  less  jar  is  felt.  Fine-grained  wheels  should  be  used  and  the  sur- 
face should  afterward  be  thoroughly  polished  by  means  of  cuttlefish 
disks,  or  with  felt  or  wooden  wheels  carrying  polishing  powder.  If 
the  grinding  should  not  be  carried  so  far  as  to  be  painful  a  slight  sensi- 
tiveness may  be  felt  for  a  few  days,  when  the  operation  may  be  resumed. 
Cataphoresis  has  been  successfully  applied  by  the  writer  for  allaying 
sensitiveness.     If  a  tooth  needs  to  be  reduced  considerably  in  length 

Fig.  708. 


Truing  up  (Farrar). 


the  dentin  may  be  exposed  on  the  cutting  edge  with  impunity,  as  it 

is  kept  free  from  decay  by  the  tongue  and  lips.     The  enamel  may  be 

beveled  on  one  or  both  surfaces  to  reduce  the  thickness  of  the  cutting 

edge. 

Approximal  Surfaces. — In  rare  instances  the  removal  of  a  slight 

amount  of  enamel  from  approximal  surfaces  of  incisors  or  canines  is 
47 


738 


ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 


pcnuissiblo  for  the  })urpose  of  makino;  room.     The  operation  should  be 

confined  to  teeth  easily  kept  clean,  to 

teeth  unusually  rounded    on  their  ap-  Fig.  710. 

proximal  surfaces,  and  they  should  be 

reduced  only  to  a  normal  contour  and 


Fig.  709. 


Truing  up  (Farrar). 


Position  of  corundum  wheel  (Farrar). 


be  thoroughly  polished.  Flat  approximal  surfaces  should  never  be 
produced,  as  caries  is  almost  sure  to  be  the  result.  The  patient  should 
be  warned  to  use  extra  care  with  the  brush  and  floss  silk. 

Disks  or  strips  of  sandpaper,  emery,  or  garnet  may  be  used  for 
removing  a  portion  of  enamel,  after  which  cuttlefish  disks  or  strips 
should  be  used  for  polishing. 

Class  6.  Two  or  More  Teeth  in  Any  or  All  of  the  Five  Mal- 
positions.— One  of  the  oldest  and  simplest  appliances,  which  requires 
very  little  skill  in  its  construction,  is  shown  in  Fig.  711.     It  can  be 

Fig.  711. 


Labial  bow  and  plate.    (From  Kingsley.) 

used  with  either  upper  or  lower  jaw,  and  consists  of  a  vulcanite  plate 
fitted  against  the  lingual  surfaces  of  the  teeth.  Imbedded  in  this  plate 
are  the  ends  of  a  wire  Avhich  extends  through  such  gaps,  when  the  jaws 
are  closed,  as  are  most  favorable,  and  around  the  buccal  and  lingual 
surfaces  of  the  teeth.  A  round  wire  is  much  better  than  a  flat  strip  of 
plate  for  this  bow,  as  it  can  be  bent  up  toward  the  gum  line  or  down 
toward  the  cutting  edges  of  the  incisors  according  to  the  necessities  of 


SEVERAL   TEETH  IN  MALPOSITION.  739 

the  case.  The  cut  shows  the  manner  of  attaching  rubber  bands  by 
M'hich  teeth  may  be  drawn  forward.  The  bow  should  be  from  yg  ^^  i" 
of  an  inch  in  advance  of  the  teeth  to  be  moved,  and  may  be  elongated 
from  time  to  time  by  hammering  the  sides  on  the  beak  of  an  anvil. 
By  attaching  rubber  bands  or  twisted  ligatures  to  the  plate,  teeth  may 
be  drawn  into  the  arch,  as  shown  in  Fig.  712,  B.  By  stretching  rubber 
bands  or  twisted  ligatures  from  either  the  wire  or  plate  to  hooks  such 
as  shown  in  Fig.  712,  A,  teeth  may  be  rotated.  For  such  purpose  it 
is  in  some  cases  best  to  solder  hooks  on  both  labial  and  lingual  surfaces 
of  a  band,  and  thus  apply  force  from  wire  and  plate  at  the  same  time. 
By  attaching  a  rubber  band  at  that  part  of  the  wire  which  emerges 
from  the  plate  (Fig.  712),  a  tooth  may  be  drawn  backward  along  the 
ridge.     If  the  wire  extends  near  to  the  cutting  edge,  an  incisor  may  be 

Fig.  712. 


Plate  and  wire  bo'iv  lor  moving  teeth  lu  all  positions 


extruded  by  ligating  a  rubber  band  at  the  neck  and  extending  it  to  the 
bow,  or  by  applying  a  twisted  ligature  in  the  same  manner.  In  some 
cases  it  is  necessary  to  ligate  the  plate  firmly  to  temporary  molars  or 
bicuspids.  This  has  a  wider  range  of  use  than  any  other  single  appli- 
ance, for  with  it  teeth  may  be  moved  outward  or  inward,  rotated  or 
elongated,  or  the  arch  may  be  spread.  (See  Fig.  712,  A,  B,  C,  I).) 
It  is,  however,  much  less  stable  and  much  more  uncleanly  than  are 
many  other  appliances  attached  directly  to  the  teeth. 

The  same  movements  may  be  made  with  the  bows  shown  in  Fig.  713. 
Bands  are  cemented  on  one  or  two  teeth  on  each  side  of  the  mouth,  pre- 
ferably two  for  stability,  in  which  case  the  bands  should  be  soldered 
together.  Tubes  are  soldered  on  both  buccal  and  lingual  sides  of  the 
bands.  In  these  tubes  are  inserted  wire  bows,  screw-cut  on  the  ends 
and  supplied  with  nuts.  One  bow  extends  around  the  labial  and  the 
other  around  the  lin<i-ual  surfaces  of  the  teeth. 


740 


ORTHODONTIA  AS  AN  OPERATIVE  PROCEDURE. 


To  these  wire  bows,  rubber  bands  may  be  attached  to  move  teeth  in 
all  directions,  for  instance  at  B,  for  niovinj^  a  lateral  incisor  into  the 
arcli ;  at  A,  for  rotating  a  central  incisor;  at  D,  for  drawing  a  canine 
backward  along  the  ridge ;  and  at  C,  for  drawing  a  lateral  forward. 


Fig.  713. 


Labial  and  liugual  bows  for  teeth  in  all  positions. 


This  last  rnbber  band  should  not  be  applied  till  after  the  canine  has 
been  moved  out  of  the  way. 

This  appliance,  made  up  of  labial  and  lingual  bows,  has  as  wide  a 
range  of  application  as  the  plate  and  bow,  and  is  much  more  stable  as 


Fig.  714. 


Appliance  for  rotating  several  teeth  at  one  time. 

well  as  much  more  cleanly.     Fig.  714  shows  the  use  of  this  appliance 
for  rotating  several  teeth  at  one  time. 

The  bows  may  be  used  independently  as  follows  :  The  labial  bow  may 


SEVERAL   TEETE  IN  MALPOSITION. 


741 


be  used  for  moving  incisors  backward  by  placing  the  nuts  behind  the 
tubes  (Fig.  663),  or  for  moving  incisors  forward  by  placing  the  nuts  in 
front  of  the  tubes  and  ligating  the  wire  to  the  incisors,  or  putting  it 


Fig.  715. 


Labial  and  lingual  bow. 

under  hooks  soldered  to  bands  on  the  incisors.  It  may  be  used  for  the 
attachment  of  rubber  bands  or  twisted  ligatures  for  drawing  incisors  for- 
ward (Fig.  729),  in  which  case  the  wire  may  be  bent  in  a  bayonet  shape 
at  the  ends,  or  the  rear  ends  of  the  tubes  may  be  closed. 

Fig.  716. 


Lingual  bow  for  moving  incisors  forward  (Matteson). 

The  lingual  bow  may  be  used  for  moving  any  or  all  four  incisors 
forward  by  placing  the  nuts  in  front  of  the  tubes.  The  anterior  portion 
of  the  wire  may  rest  in  notches  in  the  bands  on  the  incisors  (Fig.  716), 


742 


ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 


Fig.  717. 


or  a  short  piece  of  wire  may  be  soldered  to  the  front  of  tlie  bow  and 
inserted  between  the  centrals  above  the  points  and  their  mesial  snr- 
faces.  Other  short  wires  may  be  soldered  on  so  as  to  engage  the  distal 
borders  of  the  laterals  to  prevent  their  being  moved  sideways.     (See 

Fig.  715,  B.) 

Fig.  717  shows  the  writer's  modi- 
fication of  the  Coffin  spring  plate  for 
moving  incisors  forward.  A  wire 
should  be  imbedded  in  the  anterior 
portion  of  the  plate  to  project  between 
the  centrals  to  prevent  sliding  on  the 
inclined  surfaces. 

Retention  of  Teeth  Moved 
Forward. — This  has  often  been  ac- 
complished by  a  simple  vulcanite 
plate  retained  by  atmospheric  pressure 
and  impinging  on  the  lingual  surfaces 
of  all  the  teeth  involved.  Objections 
to  this  are  that  it  is  easily  displaced, 
even  sometimes  by  the  incisors  on  whose  inclined  surfaces  it  impinges ; 
retention  of  fermenting  debris  or  secretions  in  contact  with  the  teeth, 
and  liability  to  be  left  out  by  the  carelessness  of  the  patient,  when  the 
teeth  return  partly  to  their  malpositions.     Fig.  718  shows  a  retaining 


Writer's  modification  of  Colfiu  split  vul- 
canite plate. 


Fig.  718. 


e.H.A 
Angle's  retainer. 


appliance  of  Prof,  Angle's,  consisting  of  a  Avire  bent  so  as  to  rest  in 
contact  with  the  lingual  surfaces  of  the  teeth  involved,  soldered  to 
bands  on  the  canines,  and  the  ends  cemented  in  pits  drilled  in  the 
molars.  It  may  be  used  in  the  lower  arch  as  well  as  the  upper.  In 
many  cases  the  anterior  portion  only  of  this  appliance  may  be  used. 


RETAINING  PLUGS. 


743 


Several  teeth  moved  in  diiferent  positions  may  be  retained  by  bands 
soldered  together  and  cemented  in  place.     (See  Fig.  719.) 

Fig.  720  shows  Dr.  Case's  retainer/  which  consists  of  a  series  of 
bauds  soldered  together  at  their  points  of  contact  with  an  excess  of 


Fig.  719. 


Fig.  720. 


Bands  soldered  together  for  retention. 


Case's  retainer. 


Swaged  strip  for  strengthening. 


solder  in  front.  The  labial  surfaces  of  all  but  the  end  bands  are  then 
cut  away  so  as  to  leave  only  a  small  portion  between  the  teeth,  and 
these  portions  filed  so  as  to  resemble  gold  fillings.  The  appliance  is 
stiifened  by  soldering  a  piece  of  swaged  plate  to  the  lingual  surfaces. 
(See  Fig.  721.)  The  bands  should  be  constructed  of  very  thin  gold- 
faced  platinum  or  German  silver,  prefer- 
ably the  former,  and  the  whole  appliance 
firmly  cemented  to  the   teeth. 

Retaining  Plugs. —  It  not  infre- 
quently happens  that  on  account  of  the 
crowded  and  irregular  positions  of  teeth, 
cavities  of  decay  have  been  formed  which 
can  be  used,  as  suggested  by  Dr.  Farrar,  for  the  in.sertion  of  gold 
retaining  plugs  or  fillings.  For  instance,  approximal  fillings  may  be 
inserted  in  an  incisor  and  built  out  so  as  to  touch  the  contiguous  teeth 
for  retaining  a  tooth  ;  or  a  tooth  that  has  been  moved  into  line  may  be 
retained  by  gold  fillings  inserted  in  approximal  cavities  and  built  out 
laterally  so  as  to  rest  on  the  labial  or  lingual  surfaces  of  contiguous 
teeth  ;  or  a  tooth  that  has  been  rotated  may  be  retained  by  one  such 
filling. 

This  method  of  retention  is  especially  useful  with  patients  who  have 
advanced  beyond  the  years  in  which  it  is  generally  considered  advisable 
to  regulate  teeth.  The  writer  had  a  patient  forty-five  years  old  for 
whom  he  moved  two  teeth  forward  into  line.  After  an  immovable 
retaining  appliance  had  remained  in  place  for  over  two  years  the  teeth 
upon  being  released  moved  back  perceptibly.  Gold  fillings  were  inserted 
in  approximal  cavities  and  built  out  as  suggested  above,  with  the  inten- 
tion of  leaving:  them  indefinitelv. 

Care  should  be  taken   to  make  these  projections  as  slender  as  the 

^  Ohio  Dental  Journal,  January  1898,  vol.  xvii.  No.  1. 


744  ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 

strength  of  the  gold  will  permit,  so  that  the  point  of  contact  with  the 
enamel  will  be  as  small  as  possible. 

Lower  Incisors  Crowded  in  All  Positions. — This  is  a  very  common 
irregularity  owing  to  the  teeth  being  too  large  for  the  incisor  space,  or 
the  space  being  encroached  upon  by  the  canines. 

The  simplest  way  to  make  room  is  to  extract  one  of  the  crowded 
teeth.  The  four  teeth  are  so  nearly  of  the  same  size  that  few  can  tell 
without  counting  whether  there  are  three  or  four  between  the  canines. 

^Yllen  room  has  been  made,  the  remaining  teeth  may  be  brought  into 
line  by  the  same  means  that  have  been  described  for  upper  incisors. 
The  labial  bow  attached  to  bands  on  bicuspids  or  canines  will  form 
attachment  for  rubber  bands  or  ligatures  for  moving  the  incisors  into 
position.  In  some  cases  it  is  better  to  spread  the  arch  as  shown  in  Fig. 
733.  Owing  to  the  relative  positions  of  the  alveoli  of  the  central  incisor 
and  canine  to  that  of  the  lateral  incisor  there  is  always  a  tendency  for 
the  lateral  incisor  to  erupt  within  the  arch  of  the  adjoining  teeth. 

In  selecting  the  tooth  for  extraction  in  such  cases  it  would  seem  most 
natural  to  take  the  one  most  out  of  position  labially  or  lingually ;  but 


that  is  not  always  best,  because  it  often  happens,  as  Dr.  Case  has 
shown,  that  the  contiguous  teeth  already  lean  toward  each  other,  and 
if  drawn  together  after  removal  of  such  teeth  will  only  lean  toward 
each  other  all  the  more  noticeably  with  quite  a  V-shaped  space  at  the 
gum. 

If  possible,  the  tooth  for  extraction  should  be  so  selected  that  the 
contiguous  teeth  lean  from  each  other  (Fig.  722),  so  that  when  drawn 
together  they  will  be  forced  into  an  upright  position.  If,  however,  a 
wrong  selection  should  have  been  made,  the  roots  of  the  contiguous 
teeth  may  be  forced  toward  each  other  by  the  appliance  shown  in  Fig. 
821.1 

Caution. — Before  deciding  on  extraction  in  such  cases  the  operator 
should  satisfy  himself  that  the  lower  arch  does  not  need  expanding  to 
make  room  for  the  crowded  incisors. 

If  by  removing  a  tooth  the  lower  arch  is  allowed  to  contract  and  the 

^  Dr.  Case,  Dental  Review,  1898,  p.  584. 


PROMINENT  CANINES  AND  DEPRESSED  LATERALS.  745 

bicuspids  move  nearer  the  median  line,  their  cusps  may  by  wedging  con- 
tract the  upper  arch  and  cause  crowding  of  the  upper  incisors.  Fig. 
733  shows  an  appliance  for  expanding  the  lower  arch. 

Class  7.  Prominent  Canines  and  Depressed  Laterals. — Etiology. 
This  common  form  of  irregularity  may  be  due  to — 

(a)  Lack  of  development  of  the  intermaxillary  bone — constitutional. 

(6)  Teeth  too  large  for  the  jaw — indirect  heredity  :  teeth  from  one 
parent  and  jaw  from  the  other.     (See  page  690.) 

(c)  Premature  loss  of  the  deciduous  second  molars  and  forward  move- 
ment of  the  permanent  first  molars — acquired. 

(d)  Premature  loss  of  the  deciduous  canines — acquired. 
(Figs.  605,  723,  and  725  illustrate  irregularities  under  Class  7.) 
Treatment. — To  make  room  for  proper  arrangement  of  the  teeth  in 

this  class,  it  is  necessary  either  to  expand  the  arch  or  to  extract  one  or 
more  teeth. 

If  the  irregularity  is  slight,  and  the  arch  is  narrower  than  the  oc- 
cluding one,  expansion  is  indicated. 

If  both  arches  are  narrow,  both  should  be  expanded  to  restore  proper 
occlusion. 

Unless  the  arch  will  admit  of  expansion  to  advantage,  extraction  is 
better. 

If  expansion  would  make  the  arch  too  large,  or  the  anterior  teeth 
too  prominent,  extract. 

If  the  superior  maxilla  itself  is  so  narrow  that  expansion  M'ould 
make  the  bicuspids  and  molars  slant  outward  too  much,  extract. 

If  caries  is  prevalent,  extract. 

In  favor  of  expansion,  it  may  be  said  that  if  the  full  number  of  teeth 
are  retained,  the  pain  of  extraction  is  obviated,  and  the  narrow  arch  is 
widened  to  correspond  with  the  other  features. 

In  favor  of  extraction :  Room  is  gained  more  easily  ;  the  treatment 
is  simplified,  as  there  are  fewer  teeth  to  be  moved  ;  the  teeth  are  retained 
in  their  new  positions  more  easily,  because  if  the  full  number  of  teeth 
be  retained  the  same  cause  that  produced  the  irregularity  may  tend  to 
reproduce  it,  while  if  room  be  made  by  extraction  the  action  of  the  lips 
and  tongue  tends  to  move  the  teeth  into  the  normal  arch. 

In  many  cases  no  other  treatment  than  extraction  is  necessary,  as 
shown  in  Figs.  723  and  724. 

Having  decided  upon  extraction  in  any  case  under  consideration,  the 
choice  lies  between  a  lateral  incisor  and  some  tooth  posterior  to  the 
cuspid.  The  canine  should  never  be  extracted,  as  on  account  of  its 
long  root  and  prominent  position  its  loss  causes  a  depression  of  the 
corners  of  the  lip  and  wing  of  the  nose  which  can  never  be  remedied. 

The  choice  between  a  lateral  incisor  and  some  tooth  posterior  to  the 


746 


ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 


canine  depends  on  the  j)osition  of  the  apex  of  the  root  of  the  eanine, 
and  also  of  tlie  lateral.     If  the  npex  of  the  root  of  the  canine  is  so 


Fig.  723. 


Case  treated  by  extraction  only. 


situated  that  the  crown  slants  away  from  the  median  line,  or  will  do  so 
after  being  moved  into  its  normal  position,  the  extraction  of  one  or  both 
laterals  may  be  admissible.  If  a  lateral  is  unusually  far  back  of  the 
normal  line  and  the  apex  of  the  root  also,  when  the  tooth  is  moved 


Fig.  724. 


Showing  the  same  denture  as  Fig.  723  a  few  montlis  after  extraction. 

forward  till  the  cutting  edge  is  in  line  with  the  centrals  the  neck  of 
the  tooth  will  be  back  of  its  proper  position — that  is,  the  tooth  will 
have  an  unnatural  slant  forward.  This  is  not  of  as  much  importance  as 
the  position  of  the  apices  of  the  roots  of  the  canines,  but  it  should  be 
taken  into  consideration  in  connection  with  the  other  factors. 


PROMINENT  CANINES  AND  DEPRESSED  LATERALS. 


747 


One  method  of  moving  incisor  roots  is  shown  in  Figs.  823-827. 

In  very  rare  oases  a  central  incisor  may  be  extracted  to  gain  room — 
that  is,  if  very  badly  decayed,  if  an  incnrable  abscess  exist,  or  if  only 
the  root  remain  and  cannot  be  crowned  to  advantage. 

In  the  lower  arch  an  incisor  may  be  extracted  to  advantage  in  many 
cases  ;  the  four  teeth  are  so  nearly  alike  in  appearance  that  the  absence 
of  one  is  not  noticed. 

If  in  a  given  case  it  seems  best  to  extract  some  tooth  posterior  to 
the  canine,  the  choice  will  be  between  a  bicuspid  and  the  first  molar. 
If  the  bicuspids  and  fii'st  molar  be  equally  sound,  extract  the  first 
bicuspid.  That  will  leave  tw^o  teeth  for  anchorage  in  retracting  a 
canine  (Fig.  725,  left),  or,  if  the  second  molar  be  erupted  far  enough, 


Fig.  725. 


\\  I  It   r  -  modification  of  Guilford's  appliance. 

three  teeth  may  be  utilized.  Very  secure  anchorage  is  necessary  in 
this  instance,  for  the  canine  is  the  most  difficult  tooth  to  move,  and 
oftentimes  the  two  anchor  teeth  will  move  more  readily  than  the  canine. 
In  some  cases  the  canine  needs  to  be  moved  back  but  little  ;  then  the 
second  bicuspid  only  need  be  used  for  anchorage  (Fig.  725,  right),  and 
the  two  teeth  moved  toward  each  other  to  fill  up  the  space.  The  molar 
will  follow,  owing  to  the  tendency  of  the  posterior  teeth  to  move 
forward.  This  forward  movement  or  migration  of  molars  is  very 
curious,  and  is  often  a  very  great  hindrance  in  regulating,  since  they  offer 
less  resistance  as  anchor  teeth  from  that  very  cause.  Fig.  728  shows 
a  case  in  which  a  molar  has  moved  so  as  to  touch  the  canine,  yet  still 
retains  its  upright  position.  The  upper  molar  in  migration  has  less 
tendency  to  tip  forward  than  the  lower.  If,  however,  the  second  bicuspid 
or  first  molar  be  so  defective  as  not  to  be  preserved  by  filling,  the  defect- 
ive tooth  should  be  extracted.  This,  however,  will  complicate  the  case, 
as  there  are  more  teeth  to  be  moved  and  fewer  for  anchorage.  On 
account  of  the  value  of  the  molar  in  masticating  and  in  preserving 
normal  occlusion,  it  should  not  be  extracted  unless  caries  has  advanced 


748 


ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 


SO  far  that  there  is  a  doubt  whether  the  tooth  can  be  saved  by  filling  or 
crowning.     (See  page  744  on  extraction.) 

In  using  the  appliance  shown  in  Fig.  725  rubber  bands  are  gener- 
ally utilized  for  applying  force,  but  twisted  ligatures  of  silk,  linen,  or 

wire  may  be  used,  as  shown 
in  Figs.  726  and  727,  in  which 
case  there  is  less  liability  to 
pericemental        inflammation. 


Fif!.  727. 


Fi(}.  726. 


(Same  as  Fig.  725,  but  with  wire.) 


Twisted  ligatures  of  silk,  linen,  or  wire. 


Tubes  are  soldered  on  the  buccal  surfaces  of  the  bicuspid  or  molar 
bands  and  shaped  so  as  to  serve  for  hooks.  They  are  afterward  utilized 
for  holding  a  labial  bow  (Fig.  729). 

After  the  canine  is  moved  into  position,  it  may  be  retained  by  sub- 
stituting fine  platinum  or  silver  suture  wire  for  the  rubber  bauds.    The 

Fig.  728. 


Showing  migration  of  molars.    Right  first  molar  in  eontact  with  first  bicuspid,  and 
left  touching  the  canine. 

buccal  tubes,  which  served  as  hooks  in  the  first  case  (see  Fig.  726),  may 
now  be  utilized  for  inserting  the  ends  of  a  wire  bow  which  passes  in 
front  of  the  incisors.  Rubber  bands  or  twisted  ligatures  from  this  bow 
will  draw  the  lateral  inci.sors  forward.  (See  Fig.  729.)  An  inner  bow 
may  be  placed  in  the  lingual  tubes  and  utilized  for  drawing  central 


PEOMINE^^T  CANINES  AND  DEPRESSED  LATERALS. 


749 


incisors   backward,   or   rotating  them,  as  is  often  necessary  in   such 

cases. 

Fig.  729. 


Fig.  731. 


Labial  bow  added  tu  rLtrai,tin„'  appliance. 

If  either  canine  needs  rotating,  a  rubber  band  will  be  needed  on 
one  side  of  the  tooth  only,  and 
the  hook  may  be  so  placed  on 
the  band  that  the  tooth  will  be 
rotated  while  it  is  being  drawn 
back. 

Prof.  Angle  advises  the  use 

Fig.  730. 


Stationary  anchorage  (Angle). 


Angle's  drag-screw. 


of  the  drag-screw  for  retracting  canines,  as  shown  in  Fig.  730.  By 
soldering  a  long  tube  to  two  bands  which  are  cemented  to  two  teeth, 
and  extending  the  drag-screw  through  this  tube,  he  reduces  to  a  mini- 
mum the  possibility  of  the  teeth  tilting.  This  appliance  is  very 
effective.  The  position  in  which  the  hook  is  attached  to  the  canine 
band  will  depend  on  whether  it  should  be  rotated  or  not  in  retraction. 
(See  Fig.  731.) 

After  the  canines  are  moved  to  their  new  position  the  same  appli- 
ance may  remain  as  a  retainer.  It  will  be  found  that  a  canine  moved 
into  its  proper  place,  when  room  has  been  made  by  extraction,  will  need 
retention  less  than  any  other  tooth. 

Greater  anchorage  may  be  obtained  by  a  plate  such  as  shown  in 
Fig.  732,  for  it  impinges  upon  the  anterior  alveolar  ridge  and  in- 


750  OBTHODO^'TIA   AS  AN  OPERATIVE  PROCEDURE. 

cisors  as  well  us  u]k)1i  the  posterior  teeth.  Its  use  is  especially  ad- 
vautaii-eoiis  when  a  seeoiul  bicuspid  or  first  molar  has  been  extracted, 
for  then  one  or  two  teeth  must  be  moved  before  the  canine.  The  cut 
will  e.\j)lain  the  method  of  applyin*^  force  to  the  teeth  U)  be  moved. 
The  wire  or  clasp  should  encircle  the  j)ostcrior  tooth,  for  greater  anchor- 
age. After  the  second  bicuspid  has  been  drawn  back,  the  first  can  be 
moved  in  the  same  manner ;  then  the  canine.     In  many  cases  it  will 

Fig.  732. 


Plate  for  retraction. 


be  best  to  move  the  canine  by  the  reciprocal  appliance  shown  in  Fig. 
733,  so  as  to  relieve  the  anchor  teeth  from  undue  strain. 

It  is  to  be  clearly  understood  that  the  condition  shown  in  Fig.  732 
must  be  one  of  necessity,  not  of  choice. 

The  molar  is  so  important  in  masticating  and  in  preserving  the  normal 
relation  and  interlocking  of  cusps  of  occluding  teeth  that  it  should  not 
be  removed  if  it  can  be  avoided. 

Present  methods  of  crowning  molars  are  so  successful  and  perma- 
nent that  in  most  cases  crowning  should  be  resorted  to  if  the  tooth  is 
too  far  gone  to  be  filled,  even  if  a  sound  bicuspid  must  be  removed  to 
give  room. 

Fig.  733  shows  a  reciprocal  appliance  for  these  cases  by  Dr.  R.  L. 
Taylor,  of  San  Francisco.  The  laterals  are  drawn  forward  and  the 
canines  pushed  back  and  elevated  at  the  same  time,  after  the  first 
bicuspids  have  been  extracted  to  make  room.  This  has  proved  a  valu- 
able appliance  and  is  well  adapted  to  such  cases  as  are  shown  in  Fig. 
732,  after  the  bicuspids  have  been  moved  back. 

Fig.  734  shows  a  valuable  appliance  by  Prof.  Guilford  for  moving 
four  incisors  forward,  and  bicuspids  back,  to  make  room  for  canines. 
He  thus  describes  it :  *'  Magill  bands  were  made  to  fit  the  laterals,  with 
gold  spurs  extending  along  the  palatal  surface  of  the  centrals  to  insure 
uniform  movement  of  the  four  incisors.  Palatal  bands  were  also  at- 
tached to  the  first  bicuspids.     All  of  these  bands  were  reinforced  with 


PBOMIXENT  CANINES  AND  DEPRESSED  LATERALS. 


751 


an  additional  piece  of  platinum   soldered  to  the  portion  next  to  the 
space.     Through  these  reinforcements,  at  about  the  centre  of  the  tooth, 


Fig.  733. 


Dr.  K.  L.  Taylor's  reciprocal  appliance. 


holes  were  drilled  entirely  through  the  bands.  Piano  wire  was  next 
bent  into  the  form  of  small  U-shaped  springs,  with  the  ends  at  right 
angles,  similar  to  Dr.  Talbot's  plan  but  without  the  coil.  Grasping 
these  near  the  neck  with  a  pair  of  narrow-beaked  right-angle  forceps, 


Fig.  734. 


Guilford's  appliance-  tor  increasing  space. 


transversely  grooved  near  the  points  to  seize  the  wire,  the  springs  were 
placed  in  position  with  their  ends  resting  in  the  holes  in  the  bauds.  As 
from  time  to  time  tlie  force  of  these  springs  became  spent  they  were 
removed  and  their  power  renewed  l)y  enlarging  their  curves." 

In  case  of  extraction  of  first  molars,  the  bicuspids  may  be  moved 
backward  and  the  incisors  forward  by  Prof.  Guilford's  appliance. 

Fig.  735  shows  Prof.  Angle's  method  of  reinforcing  the  anchor 
teeth  bv  a  wire  bar  extendiuff  to  the  lateral  incisor. 


752  ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 

In  many  cases,  after  extraction  of  a  first  bicuspid  the  only  problem 

Fig.  735. 


Angle's  reinforcement. 

is  to  draw  the  canine  into  line  or  move  it  lingually.     This  may  be  ac- 
complished by  any  of  the  appliances  described  in  Class  2. 

Fig.  736. 


.  i'  I' 


Drawing  canine  in 

Fig.  736  shows  another  method  of  Prof.  Angle's  for  drawing  the 

Fig.  737. 


canine  in. 


Jackson's  appliance  for  lower  arch. 

The  lower  canine  is  the  most  difficult  tooth  to  move.  If  the  first 
bicuspid  be  extracted  to  make  room,  the  second  bicuspid  and  first  molar 
will  in  many  cases  be  moved  forward  in  an  attempt  to  use  them  as 


PROMINENT  CANINES  AND  DEPRESSED  LATERALS. 


753 


anchorage  in  retracting  the  canine  either  with  a  screw  or  elastics.  If 
a  first  molar  has  been  lost,  we  have  the  sum  of  difficulties, — three  teeth 
to  move  and  only  the  second  molar  for  anchorage.  It  is  often  neces- 
sary to  construct  an  appliance 
of  such  a  shape  that  all  the 
other  teeth  can  be  used  as 
anchorage. 

Fig.  739. 


r38 


Jackson's  appliance  for  lower  arch. 


Flat  tube  for  piano-wire  spring. 


Figs.  737,  738  show  Dr.  Jackson's  method  of  retracting  the  lower 
canine  in  such  cases.  The  base  wire  rests  against  all  teeth  that  it  is 
not  desired  to  move  and  gives  effective  anchorage. 

Fig.  739,  A,  shows  another  method  of  applying  a  piano-wire  spring 
by  bending  a  loop  on  one  end  and  inserting  it  in  a  flat  tube  soldered 
to  a  molar  band  ;  the  spring  is  thus  prevented  from  turning.     The  loop 

Fig.  740. 


Stability  of  anchorage. 

may  be  so  bent  that  the  spring  may  be  inserted  in  the  posterior  end  of 
the  flat  tube,  as  shown  at  b,  Fig.  739. 

''  When  great  immobility  of  the  anchorage  tooth  is  required,  use  for 
banding  material  German  silver  or  platinized  gold,  No.  30  gauge  and 
as  wide  as  the  tooth  will  permit.  When  these  are  contoured  and  fitted, 
solder  the  power  tube  at  the  gingival  mai'gin.  (See  Fig.  740.)  This 
should  be  sufficiently  long  to  permit  reinforcing  it  at  either  end  with 
solder  to  the  full  width  of  the  tooth,  and  large  enough  to  carry  a 
power  rod  that  will  be  inflexible.  Where  it  is  possible,  the  power  tube 
may  rest  above  the  gingival  margin,  soldered  to  an  extension  plate 
that  is  fitted  or  swaged  to  the  surface  of  the  crown,  and  so  shaped  as  to 
freely  clear  the  gum. 

48 


754 


ORTHODONTIA   AS  AN   OPERATIVE  PROCEDURE. 


"If  tile  power  tube  is  extended  forward  to  the  first  bieiispid  and 
its  anterior  end  allowed  to  rest  u})on  a  narrow  })rojection  soldered  to 
the  bicuspid  band,  it  will  add  greatly  to  tlu;  stability  of  the  anchorage. 

"  It  w'ill  be  seen  that  any  tendency  of  the  molar  to  tip  forward 
will    curry  the  anterior  end   of   the   tube   almost   directly  toward   the 


Fig.  741. 


Author's  combination  for  expansion. 


root  of  the  bicuspid,  the  movement  being  prevented  by  the  rest.  Nor 
will  any  such  device  offer  any  special  obstruction  to  the  movement  of 
the  bicuspid,  the  rest  sliding  along  the  tube." 

The  "  power  bar,"  or  drag-screw^,  should  end  in  a  hook  engaged  in 
a  tube  on  the  canine  or  any  other  tooth  tliat  needs  to  be  moved. 


Matteson  caps  in  place  of  bands  in  ay)pliance  for  expansion. 


Spreading  the  Arch. — For  spreading  the  arch  an  appliance 
should  be  firmly  fixed  upon  the  teeth  and  should  have  sufficient  power, 
which  can  be  well  regulated.  For  such  an  appliance  the  writer  has 
made  a  combination  of  Magill  bands.  Angle's  jack-screw,  and  the  coil 


SPREADING  THE  ARCH. 


Too 


spring,  as  shown  in  Fig.  741.  While  resembling  other  devices  for  the 
same  purpose,  it  has  this  distinction  :  The  bar  connecting  the  bauds  on 
the  lingual  surfaces  of  the  teeth  is  perforated  at  short  intervals  by 
holes  in  which  are  fitted  the  ends  of  a  Talbot  spring  or  an  Angle  jack- 
screw.  This  bar  should  be  stiff,  about  No.  23  B.  &  S.  gauge.  The 
position  of  the  screw  or  spring  may  be  changed,  according  to  the  part 
which  needs  the  greater  expansion.     If  necessary,  two  springs  dt  two 

Fig.  743. 


Writer's  combination  with  Angle's  jack-screw. 


jack-screw^s  may  be  used  at  the  same  time.  The  coiled  spring  should 
be  bent  to  conform  to  the  palatal  vault,  so  as  to  interfere  but  little 
with  the  patient's  tongue  as  does  the  jack-screw. 

In  case  of  very  short  molars  and  bicuspids  it  is  best  to  use  Matte- 
sou  caps  in  place  of  bands,  as  shown  in  Fig.  742. 

Fig.  744. 


Writer's  appliance  for  widening  lower  arch  and  moving  incisors  forward. 

Fig.  743  shows  tlie  use  of  the  jack-screw  and  Fig.  744  the  appliance 
for  the  lower  arch.     In  this  the  Matteson  spring  is  used  with  two  coils 


756 


ORTHODOyilA  AS  AN  OPERATIVE  PROCEDURE. 


between  which  is  ii  straight  part  which  lies  near  the  Hoor  of  the 
mouth. 

When  the  arch  has  been  spread  the  bent  wire  c,  Fig.  741,  is  sub- 
stituted for  the  spring  or  jack-screw  for  retention.  It  may  lie  along 
the  necks  of  the  teeth,  and  in  such  position  be  utilized  for  attachment 
of  rubber  bands  for  retracting  or  rotating  incisors,  as  shown  in  Figs. 
667  and  713.  The  long  wire  a,  b,  Fig.  741,  is  used  for  moving  incisors 
forward,  as  shown  in  Fig.  729.  These  two  wires  are  the  labial  and 
lingual  bows  previously  referred  to. 

Fig.  745  shows  one  of  the  author's  "partly  made"  appliances, 
which  can  be  readily  applied  to  the  teeth  of  a  patient  or  to  a  plaster 

Fig.  745. 


Partly  made  appliance  for  expansion. 


cast  by  bending  the  partly  made  bands  around  the  teeth  and  completing 

them  as  in  Fig.  630. 

Fig.  746. 


Partly  made  expander  applied  to  plaster  cast. 


The  perforated  bar  soldered  to  the  first  band  ribbon  slides  through  a 
flat  tube  on  the  second  band  ribbon,  and  thus  allows  adjustment  accord- 
ing to  the  amount  of  room  desired  between  the  bands.  Fig.  746  shows 
the  completion  of  the  appliance. 


THE  POINTED   OR   GOTHIC  ARCH. 


757 


Class  8.  The  Pointed  or  Gothic  Arch  (the  V-shaped  Arch) 
(called  the  Lancet  Arch  by  Dr.  Guilford). — Etiology. — The  pointed 
arch  (generally  miscalled  the  V-shaped  arch)  may  be  due — 

(«)  To  the  presence  of  teeth  too  large  for  the  jaw — indirect  heredity;  or 

(6)  To  the  first  permanent  molar  having  moved  forward  from  its 
normal  position  on  account  of  premature  loss  of  the  second  deciduous 
molar — acquired. 

In  either  case,  taking  the  first  molar  as  a  fixed  point  for  the  base  of 
the  arch  on  each  side,  the  teeth  forward  of  that  point  must  arrange 
themselves  in  a  portion  of  the  jaw  which  is  too  small  for  them.  The 
incisors  erupt  first,  the  bicuspids  next,  and  the  canines  last.  It  depends 
on  the  manner  of  approximal  contact  whether  the  result  is  a  pointed 
arch,  a  constricted  arch,  or  results  in  Class  7 — "  Prominent  canines  and 
depressed  laterals." 

If  all  of  these  teeth  erupt  in  proper  alignment,  they  will  touch  each 
other  approximally  like  the  stones  of  an  arch  ;  the  second  bicuspid  not 

Fig.  747. 


Pointed  arch  (V  s,h  ipi  d  irch) 


having  sufficient  room — either  from  its  extra  size  or  because  the  first 
molar  has  taken  part  of  its  room — will  crowd  the  first  forward,  and  the 
canine,  erupting  as  a  Avedge  in  front  of  the  bicuspids,  which  are  immov- 
ably fixed  against  the  first  molar,  will  crowd  the  incisors  forward, 
because  they  are  situated  in  a  thin  alveolar  -process  which  is  easily 
moved.  As  the  incisors  move  forward,  crowding  upon  each  other,  they 
rotate  in  their  sockets  and  assume  the  V  siiape.^ 

(c)  The  teeth   may  assume  a  pointed  arch    from  having  too  much 
room,  either  on  accoinit  of  extraction  or  from  being  too  small  for  the  jaw. 
When  the  teeth  are  (lei)rived  of  approximal  support  there  is  a  tendency 
for  the  sides  of  the  arch  to  flatten  or  move  toward  the  median  line. 
'  See  Talbot,  3cl  ed.,  chap,  xxxii.,  and  Ottolengiii,  Dental  Coi^mos,  June  1892. 


758 


ORTHODONTIA  AS  AN  OPERATIVE  PROCEDURE. 


The  semi-V  of  Dr.  Talbot's  classification  is  one  in  which  the  causes 
named  have  operated  on  one  side  only  of  the  arch.     Fig.  748  shows  a 

serai-V  arch  due  to  the  last  cause 
^  mentioned. 

{d)  The  V  shape  assumed  by 
the  central  incisors  may  be  due  to 
lack  of  development  of  the  inter- 

FiG.  749. 


Semi-V-shaped  arch. 


Apices  of  roots  too  near  together. 


maxillary  bone  at  the  median  suture.  This  would  bring  the  apices  of 
the  roots  of  these  teeth  nearer  each  other  than  is  normal.  As  the  teeth 
erupt  they  may  come  in  contact  with  each  other  above  the  gum  line,  but 
be  separated  from  each  other  at  the  mesio-incisal  angles.  If  they  are 
now  crowded  together  by  the  lateral  incisors,  or  if  an  attempt  be  made 
to  draw  them  together  by  means  of  a  rubber  band  or  ligatures,  they  will 
roll  upon  each  other  in  such  a  manner  that  when  the  mesio-incisal 
angles  touch  they  have  also  assumed  a  V  shape  with  the  apex  of  the 
V  pointing  forward. 

Conversely,  when  a  V  shape  of  tiiis  kind  is  reduced  by  double  rota- 
tion,^ the  teeth  will  assume  the  position  shown  in  Fig.  749. 

The  old  theory  that  it  was  due  to  mouth-breathing  is  no  longer  ten- 
able, as  it  has  been  demonstrated  that  the  pressure  of  the  muscles  upon 
the  teeth  in  such  action  is  not  sufficient  to  cause  this  deformity.  This 
has  been  proved  by  examination  of  a  great  number  of  children  in  schools 
and  public  institutions. 

Ti^eatment. — The  treatment  of  the  pointed  arch  depends  on  the 
relation  in  size  between  the  jaw  and  teeth.  If  the  teeth  are  not  too 
large  for  the  jaw,  and  the  deformity  consists  in  the  flattening  of  the 
sides  of  the  arch,  the  operation  is  comparatively  simple.  If  pressure 
be  brought  to  bear  on  the  summit  or  point  of  the  arch  while  the  base  on 
each  side  is  fixed,  the  sides  will  spring  outward  like  an  arch  of  whale- 
bone.    (See  Fig.  750.) 

Many  pointed  arches  are  also  cases  of  upper  protrusion,  and  will  be 
treated  of  under  that  division. 

One  of  the  oldest  appliances  and  a  very  satisfactory  one  is  shown  in 

^  See  Class  3. 


THE  POINTED   OR   GOTHIC  ARCH.  759 

Fig.  751.     The  posterior  teeth  shoukl  be  partially  surrounded  by  the 

Fig.  750. 


Angle's  appliance  for  spreading  arch  and  reducing  V  shape. 

plate,  or  by  wire  or  clasps  imbedded  in  the  plate,  to  give  firm  anchor- 
age. The  rubber  bands  attached  to  the  T-piece  between  the  central 
incisors  should  be  attached  to  the  edges  of  the  plate  as  shown,  in  order 
to  apply  the  force  in  a  direct  line  with  the  movement  desired. 

Fig.  751. 


Plate  for  reducing  V  arch  iKingsley). 

Bauds  and  a  labial  bow  (Fig.  759)  may  be  used,  in  which  case  the 
bands  should  be  applied  to  tlie  posterior  teeth.  The  bow  should  be  of 
elastic  wire,  not  smaller  than  No.  1 6,  and  so  shaped  as  to  press  on  the 
centrals  only  at  first.  As  these  teeth  move  back  and  press  on  the  late- 
rals, and  these  in  turn  on  the  canines,  and  so  on,  the  arch  will  spread 
out  and  can  thus  be  mcMildod  to  the  shape  that  has  been  given  to  the 
bow.  This  may  be  assisted  by  rubber  bands  from  the  bow  over  the 
bicuspids  and  canines. 


(60 


ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 


In  some  cases  tlie  nrdi  must  he  spread  before  attempting  to  reduce 
the  V  shai)e,  in  which  case  the  appliance  shown  in  Fig.  741  may  be  used. 

Fig.  752  shows  the  second  stage  in  the  treatment  of  a  pointed  arch. 
The  arch  is  first  spread  by  means  of  a  coil  spring  acting  on  a  band 


Writer's  lingual  bow  and  rubber  bauds  for  rotation  after  spreading  the  arch. 

on  the  first  bicuspids,  reinforced  by  bars  resting  on  the  canines  and 
second  bicuspids.  After  sufficient  room  has  been  gained  the  lingual 
bow  may  be  inserted  to  retain  the  width  of  the  arch.  From  this  bow 
a  rubber  band  or  a  twisted  ligature  should  be  extended  to  a  T-piece 
between  the  central  incisors  or  to  a  hook  on  a  band  on  each  central 
incisor  for  the  purpose  of  rotating. 

Fig.  753. 


Upper  protrusion— cause  (a)  or  (&). 

Class  9.  Upper  Protrusion. — Etiology. — Protrusion  of  the  upper 
anterior  teeth  may  be  due  to  several  causes  : 

(rt)  Abnormal  (excessive)  development  of  the  upper  maxilla — con- 
stitutional. 

(6)  Teeth  too  large  for  the  jaw — indirect  heredity. 

(c)  Premature  loss  of  the  second  deciduous  molar,  and  forward  move- 
ment of  the  first  permanent  molar — acquired. 


UPPER  PROTRUSION. 


761 


(d)  Thumb-sucking — acquired.     (See  Fig.  757.) 

(e)  Lack  of  development  of  the  lower  maxilla  (the  upper  protrusion 
is  then  apparent  rather  than  real) — constitutional. 


Fig.  754. 


Protrusion— cause  (c)  (Talbot 


(/)  Premature  loss  or  injudicious  extraction  of  the  first  permanent 
molars — acquired.  Prof.  Guilford  says  of  such  extraction  :  "  The  re- 
sult is  that  the  lateral  pressure  so  necessary  to  proper  expansion  is  lack- 
ing in  one  jaw  while  in  the  other  normal  enlargement  continues." 


Fig.  751 


Fig.  756. 


Apparent  protrusion  due  to  lack  of  develop- 
ment of  lower  maxilla  (Talbotj. 


Dr.  Louis  Jack's  drawing  (in  Dental  Cusmos) 
showing  deformity  from  too  early  extrac- 
tion of  first  permanent  molar. 


(g)  Weak  structure  of  the  upper  maxilla,  which  allows  the  teeth  to 
be  forced  forward  by  occlusion  with  a  large  lower  maxilla  of  hard  and 
dense  structure  with  short  rami — acquired.     (See  Fig.  757.) 


7<)2 


ORTHODONTIA    AS  AN  OPERATIVE  PROCEDURE. 


(A)  It  may  be  due  to  extraction  of  tlio  lower  Hrst  molars  at  an  age 
when  they  were  the  only  masticating  teeth,  as  might  be  the  ease  during 
an  interval  between  the  loss  of  the  deciduous  molars  and  the  eruption 
of  the  bicuspids.  The  impaction  of  the  lower  incisors  upon  the  inclined 
lingual  surfaces  of  the  upper  incisors  might  move  them  forward,  thus 
causing  U])per  protrusion.     (See  Fig.  756.) 

Thinnb-xuckiiKj. — To  this  practice  were  formerly  ascribed  all  cases  of 
upper   ])n)trusion,   until   inquiries  developed   the  knowledge  that  in  a 

Fig.  757. 


Upper  protrusion — cause  (d),  from  thumb-sucking.    (Talbot.) 

majority  of  cases  no  such  habit  had  existed,  or,  if  so,  had  been  aban- 
doned before  the  eruption  of  the  permanent  teeth.  The  fact  that  the 
habit  of  thumb-sucking,  which  usually  begins  before  the  temporary 
teeth  are  erupted,  is  indulged  in  during  the  years  when  the  bony  parts 
are  especially  soft  and  yielding  and  is  discontinued  before  the  eruption 
of  the  permanent  teeth,  and  that  nevertheless  upper  protrusion  rarely 
occurs  with  the  deciduous  teeth,  has  completely  overthrown  the  old 
theory.  Yet  thumb-sucking  is  occasionally  persisted  in  till  twenty- 
eight  permanent  teeth  are  erupted,  and  occasionally  causes  protrusion. 
Dr.  Ottolengui  says  : ^  "It  seems  to  me  that  if  it  is  ever  true  at  all 
that  thumb-sucking  can  cause  a  protrusion  of  the  jaw,  we  have  it  within 
our  means  to  determine  when  such  a  condition  has  so  resulted.  If  a 
given  case  of  protrusion  is  attributable  to  thumb-sucking,  it  must  of 
necessity  follow  that  had  the  child  not  practiced  the  habit  the  jaw 
would  not  have  protruded.  Admitting  this,  then,  we  come  to  this — 
that  the  protrusion  has  occurred  in  one  of  two  ways  :  First,  the  length 
of  the  arch  around  the  circle  has  not  been  enlarged,  but  the  projection 
has  been  produced  by  a  flattening  of  the  sides — p;)inted  arch.  The  teeth 
^  Dental  Cosmos,  1892,  vol.  xxxiv.  p.  447. 


UPPER  PROTRUSTON. 


763 


being  normal,  but  simply  distorted,  it  must  folloAv  that  such  a  case  could 
be  restored  without  extracting  any  teeth,  or  in  plainer  language,  that  by 
widening  the  jaw  and  reducing  the  forward  prominence  we  may  obtain  a 
normal  mouth  Avith  all  the  teeth  in  proper  position.  The  second  class  of 
cases  is  where  the  length  around  the  arch  is  increased,  thus  accounting  for 


Pointed  arch.  Protrusion  with  spaces.  Protrusion— teeth  too  large. 

Labial  bow  for  three  cases  of  protrusion. 

the  anterior  prominence.  In  such  a  case  the  pressure  would  be  supposed 
to  have  moved  the  teeth  forward,  new  tissue  forming  the  Avhile.  The 
result  would  be  a  normal  occlusion  from  the  bicuspid  region  backward, 
but  a  protrusion  forward,  with  a  distinct  spacing  between  the  teeth. 
This  of  course  M^ould  be  another  condition  which  could  be  corrected 
without  the  loss  of  a  tooth." 

Fig.  759. 


Labial  bow  for  reducing  upper  protrusion. 

Treatment. — The  treatment  of  upper  protrusion  will  be  considered 
under  four  heads : 

A.  Where  there  is  a  flattening  of  the  sides  of  the  arch  (pointed  arch). 

B.  Where  there  are  spaces  between  the  teeth. 

C.  Where  a  tooth  must  be  sacrificed  on  each  side  to  make  room. 


764 


ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 


D.  Where  there  is  not  sufficient  anchorage  inside  the  mouth. 

The  first  three  classes  may  be  treated  in  the  same  manner,  by  means 
of  ihe  labial  bow  shown  in  Fig.  759.  The  bow  should  be  of  stiff 
elastic  wire,  not  smaller  than  No.  16,  which  will  retain  its  shape,  and 
shoidd  be  bent  at  first  into  the  exact  form  desired  for  the  arch  in  the 
finished  case,  and  should  be  prevented  from  sliding  toward  the  gum 
by  notched  bands  on  central  incisors. 

In  class  A  (pointed  arch)  it  will  press  on  the  central  incisors  only, 
and  cause  the  flattened  sides  of  the  arch  to  spread  outward.  If  they 
do  not  readily  do  so,  rubber  bands  may  be  extended  from  the  sides 
of  the  bow  over  any  teeth  desired. 

In  most  cases  the  greatest  possible  stability  of  anchorage  is  neces- 
sary ;  then  bands  for  the  bicuspid  ;  and  both  should  be  soldered  to- 
gether (Fig.  760,  a).      Such  bands  should   be   made  of  No.  30  band 

Fi<i.  760. 


Increased  anchorage. 

ribbon  as  wide  as  the  crown  will  allow.  Fiff.  629,  E,  shows  the  double 
band  partly  constructed. 

In  many  cases  the  second  molar  is  too  short  for  a  band,  but  some- 
times a  stiff  wire  may  be  extended  back  from  the  first  molar  band  so  as 
to  hook  around  the  second  molar,  perhaps  extending  slightly  under  the 
gum  or  pressing  it  away  (Fig.  760,  6). 

In  class  B  the  teeth  will  be  drawn  toward  each  other  and  the  spaces 
closed ;  and  in  class  C  if  the  first  bicuspids  are  extracted  the  six  anterior 
teeth  will  be  drawn  back  till  the  canines  occupy  the  vacant  spaces.  If 
these  six  teeth  were  in  the  curve  of  the  normal  arch  they  will  be  moved 
back  in  the  same  position.  If  some  are  more  prominent  than  others, 
the  more  prominent  ones  will  be  drawn  back  first  and  all  moulded  into 
the  desired  alignment. 


UPPER  PROTRUSION. 


765 


The  tooth  to  be  extracted  will  depend  on  the  same  rules  as  in  Class 
7 — "  Prominent  canines  and  depressed  laterals." 

In  some  cases  the  upper  protrusion  is  slight,  so  that  the  anterior 
teeth  do  not  need  to  be  moved  back  more  than  half  the  space  left  by 


Fig.  761. 


(lUilford's  appliance  for  retracting  upper  incisors. 

the  first  bicuspids.  Then  it  is  an  advantage  to  have  the  posterior  teeth 
— the  anchor  teeth — move  forward  half  the  distance  and  fill  up  the  gap, 
unless  that  plan  would  disarrange   the  occlusion,  in   which   case  the 

Fig.  7(i2. 


Labial  bow  and  plate  (Kingsley). 

bicuspid  only  may  be  moved  forward  so  as  to  divide  the  space.  The 
cusps  of  the  upper  bicuspid  and  the  occluding  teeth  may  in  some  cases 
bo  advantageously  ground  so  as  to  improve  the  occlusion. 

Fig.  782  shows  Prof.  Anglo's  appliance  for  reducing  the  lower  arch, 
which  can  be  applied  also  to  the  upper.  By  a  careful  examination  it 
will  be  seen  to  be  practically  a  labial  bow  made  up  in  three  sections. 


768 


ORTHODONTIA    AS  AN  OPERATIVE  PROCEDURE. 


In  obstinate  cases  it  wonld  be  the  best  appliance,  for  sometimes  with 
the  bow  the  teeth  crowd  together  and  tend  to  overlap.  This  is  impos- 
sible with  Anglo's  appliance,  for  all  the  force  is  ap])lied  to  the  canines, 
which   in  turn  draw  the  incisors   alontr  with   them. 


Fi(i.  7r>;^. 


Jackson's  method. 

The  anterior  teeth  may  be  moved  back  by  means  of  a  plate  and 
elastic  bands  such  as  shown  in  Fig.  761.  The  plate  should  be  well 
secured  by  clasps  around  the  molars. 

Fig.  762  shows  Dr.  Kingsley's  plate  with  a  labial  bow  of  stiff  wire, 
the  elasticity  of  which  is  depended  upon  for  moving  the  anterior  teeth. 
At  each  visit  of  the  patient  the  ends  of  the  bow  are  bent  so  as  to  re- 


FiG.  764. 


Fig.  765. 


Case  of  upper  protrusion. 


Result  of  treatment  with  cap  and  bit. 


new  the  pressure.    This  is  an  excellent  appliance  for  reducing  a  pointed 
arch. 

It  is  sometimes  advisable  to  retract  the  canines  first,  by  some  of  the 
methods  described  in  Class  5,  and  then  the  incisors  by  the  plan  just 
mentioned. 


UPPER   PROTRUSION. 


767 


Fig.  763  shows  the  use  of  piano  M'ire  after  the  method  of  Dr. 
Jackson,  which  exphiins  itself.  The  springs  attached  to  the  vulcanite 
plate  or  to  the  Jackson  base  wire  and  crib  "  following  around  from  each 
side  of  the  labial  surfaces  of  the  canines  and  incisors,  pass  each  other  at 
the  median  line  "  and  ])ress  like  long  fingers. 

For  moving  back  the  roots  of  the  teeth  after  the  crowns  have  been 
moved,  see  page  796. 

•  Class  D  may  include  any  of  the  others.  The  anchorage  may  be 
insufficient  for  the  first  two  classes  on  account  of  the  loss  of  posterior 
teeth  from  caries.     In  class  C  the  teeth  to  be  moved  may  exceed  in 

Fig.  766. 


Writer's  form  of  cap  and  bit  for  retraction. 

number  the  anchor  teeth  so  that  the  latter  will  move  instead  of  the 
anterior  teeth.     Figs.  764  and   765   show  such  a  case.     In  such  in- 


FiG.  767. 


The  bit. 

stances  it  is  necessary  to  use  the  back  of  the  head  for  anchorage. 
The  first  recorded  instance  of  such  use  was  by  Dr.  Norman  W. 
Kingsley  in  1865. 

Various  complicated  appliances  for  attachment  to  the  anterior  teeth 
have  been  described  by  different  authors.    Fig.  766  shows  a  very  simple 


768 


ORTHODONTIA  AS  AN  OPERATIVE  PROCEDURE. 


one  first  used  by  the  autlior  in  18S0.  It  consists  of  a  vulcanite  cap  fit- 
ting the  labial  and  i)art  of  the  lingual  surfaces  of  the  anterior  teeth  (Fig. 
767).  In  this  is  imbedded  a  steel  or  German-silver  wire,  about  No.  12, 
so  that  the  ends  will  protrude  between  the  lips  at  the  corners  of  the 
mouth.  These  ends  are  bent  into  hooks,  and  extended  far  enough  so 
that  elastics  from  them  to  the  cap  on  the  back  of  the  head  will  not  touch 
the  cheeks.  These  extended  arms  may  be  bent  to  conform  to  the  curve 
of  the  checks,  but  should  not  touch  them.  The  cloth  cap  is  such  as  any 
seamstress  can  make  easily,  and  extends  forward  above  and  below  the 
ear.  On  these  projecting  ends  are  sewed  dress-hooks.  For  power  use 
round  or  flat  elastic  cord.     Tie  a  knot  in  one  end,  place  it  in  the  hook 


P^IG. 


^.^-^"'^'^ 

/^ 

!| 

f- 

X.^ 

rT^to 

^^    -^fe^ 

s^^^^ 

Wi'~~ 

M                 / 

^V*       '  IBI^^^H 

/      Jf^^H 

^ ^ 

'~~^^mmi0mk.    1 

Ik.    ,.J^^^^ 

"^^C^^ 

^21-«L 

'^"giptji^^**^ 

-=™=^  ^ 

I                  ^^^^ 

— =^      ~—       =^B^ 

1 

" 

y ^^    / 

"^^ 

^=^=5^^^^^^p=— ' 

\. 

Ten  teeth  moved  at  once.    Condition  before  treatment. 


Fig.  769. 


Same  denture  after  treatment. 


above  the  ear,  extend  it  forward  over  the  hook  of  the  "  bit "  and  back 
to  the  hook  on  the  cap  below  the  ear,  and  tie  a  knot  in  it  to  secure  it. 
In  most  cases  two  or  more  strands  will  be  needed ;    if  so,  extend  the 


UPPER  PROTRUSION. 


'69 


cord  forward  again  over  the  hook  on  the  bit,  and  back  again  to  the 
upper  or  to  the  lower  hook.  By  thus  varying  the  number  of  strands 
from  the  hook  above  or  below  the  ear,  the  movement  may  be  made 
directly  backward  from  the  cutting  edges,  or  upward  and  backward 
somewhat  in  the  line  of  the  roots,  in  which  case  the  teeth  will  be  forced 
up  into  the  sockets,  or  shortened.  The  ends  of  the  wire  passing  out 
of  the  corners  of  the  mouth  may  be  adjusted  by  bending  upward 
to  just  the  right  degree,  so  that  the  pressure  of  the  "bit"  will  not  be 
on  the  cutting  edges,  but  at  the  necks  of  the  teeth,  or  even  higher,  so 
as  to  move  the  roots  and  process  also.  To  insure  this,  the  vulcanite 
portion  of  the  "bit"  should  pass  over  the  cutting  edge  so  as  to  grasp 
the  lingual  surface. 

This  cap-and-bit  appliance  may  be  worn  at  night  only,  or  at  such 
other  times  as  will  not  prevent  the  patient  from  attending  school.  The 
movement  will  be  facilitated  if  a  retaining  appliance  be  worn  during 
such  times  as  the  cap  is  not  in  use.  The  posterior  teeth  will  often 
aiford  sufficient  anchorage  for  retention. 

This  appliance  is  especially  valuable  in  cases  in  which  it  is  necessary 
to  select  for  extraction  second  bicuspids  or  first  molars  on  account  of 
caries,  for  then  the  number  of  teeth  for  anchorage  is  decreased  and  the 
number  to  be  moved  is  increased. 

Figs.  768  and  769  show  a  case  in  which  ten  teeth  were  moved  at 
once,  by  this  appliance. 

Fig.  770. 


Angle's  appliance  for  retraction. 


During  the  daytime,  when  the  cap  is  not  worn,  the  teeth  may  be 
retained  by  the  labial  bow  shown  in  Fig.  759,  which  explains  itself. 


49 


770 


ORTHODONTIA  AS  AN  OPERATIVE  PROCEDURE. 


The  nuts  slioiiltl  be  turned  in  the  morning  only  enough  to  retain  but 
not   to  move  the  teeth. 

It' the  u|)i)er  ])rotrusion  is  complicated  with  other  irregularities,  such 
as  a  pointed  arch,  or  single  teeth  in  any  of  the  lirst  five  positions,  Prof. 
Angle's  ai)pliance  shown  in  Figs.  770,  771  will  be  found  very  satisfac- 
tory. The  labial  bow  is  held  in  ])()sition  by  bands  on  the  central  in- 
cisors, having  notches  formed  in  the  united  ends  on  the  labial  surfaces, 
c,  c.  The  ends  slide  through  tubes  on  molar  bands.  From  the  front 
of  the  bow^  projects  a  short  wire  ending  in  a  ball  on  which  is  adjusted 
the  socket  of  the  traction  bar,  a.  From  the  ends  of  this  traction  bar 
rubber  bands  extend  to  a  cap  on  the  back  of  the  head,  as  shown 
in  Fig.  772.     As  this  wire  bow  is  moved  backward  by  the  external 

Fi(i.  772. 


Angle's  cap. 

force,  it  will  move  the  teeth  with  which  it  comes  in  contact  and  mould 
the  arch  to  the  shape  of  the  bow  ;  or,  if  single  teeth  need  special  move- 
ments such  as  rotation,  elevation,  etc.,  it  may  be  accomplished  by  means 
shown  in  Fig.  713.  Dr.  Angle  advocates  the  use  of  wire  ligatures 
with  the  bow  for  various  movements  of  the  teeth,  as  shown  in  Fig. 
773.  The  rubber  bands  shown  on  the  sides  of  the  bow  are  for  retain- 
ing the  teeth  during  the  day,  while  the  cap  is  not  Avorn. 

For  retention,  nothing  is  better  than  the  labial  bow,  as  shown  in 
Fig.  759  ;  but  Dr.  Case's  retainer  (Fig.  720)  is  much  less  conspicu- 
ous. The  anchor  bands  may  be  placed  on  the  second  bicuspids  or  first 
molars,  or  on  both. 

"  Jumping  the  Bite." — Many  cases  of  apparent  upper  protrusion 
are  due  to  lack  of  development  of  the  lower  maxilla,  so  that  the  lower 
teeth  close  one  cusp  back  of  the  normal  position  and  the  lower  second 


''JUMPING   THE  BITEr 


111 


bicuspid  closes  beliind  the  upper  second  instead  of  in  front  of  it,  which 
is  the  normal  articulation.  Fig.  774  shows  such  a  case  of  disto- 
lingual  occlusion. 

Fig.  773. 


Wire  ligatures  with  the  bow,  for  various  movements  of  the  teeth. 

If  the  lower  jaw  can  be  moved  forward  the  width  of  a  bicuspid,  or 
less,  sometimes,  the  normal  occlusion  will  be  produced.  This  move- 
ment is  termed  "jumping  the  bite,"  and  originated  with  Dr.  N.  W. 
Kingsley  more  than  twenty  years  ago. 

The  lower  jaw  may  be  voluntarily  moved  forward  but  not  backward. 
Any  patient  v/ith  an  abnormal  occlusion  can  move  the  lower  jaw  for- 


¥m. 


Disto-lingual  occlusion. 

ward  the  width  of  a  tooth  and  thus  occlude  normally.  If  this  can  be 
made  a  permanent  habit,  the  patient  will  have  "jumped  the  bite." 

Unless  some  change  takes  place  in  the  glenoid  cavity,  such  as  a  filling 
up  of  its  posterior  portion,  or  in  the  condyle,  such  as  the  bending  of  the 
neck,  as  suggested  by  Dr.  Case,  or  in  the  angle  of  the  jaw  itself,  so  as 
to  ])revent  the  jaw  from  moving  back  into  its  old  position,  the  new 
position  cannot  be  maintained. 

The  first  recorded  operation  of  this  kind  was  described  as  follows 


772 


ORTHODONTIA  AS  AN  OPERATIVE  PROCKDURE. 


by  Dr.  Kingslcy  :  ^  "Fig.  775  shows  another  application  of  tlie  in- 
clined plane  somewhat  out  of  the  ordinary  course.  It  was  adapted 
to  the  inside  of  the  upper  dental  arch,  and  the  inclined  surface  pro- 
jected below  and  caught  the  lo\ver  incisors.  The  object  was,  not  to 
protrude  the  lower  teeth,  but  to  change  or  junij)  the  bite  in  the  case  of 
an  excessively  retreating  lower  jaw.     In   the  engraving   is  shown  a 

Fig.  775. 


Kingsley"s  appliance  for  "jumping  the  bite." 

gold  bar  worn  across  the  front  of  the  upper  incisors  to  reduce  their 
prominence." 

Figs.  776,  777  illustrate  a  case  treated  by  Dr.  E.  H.  Cutter  of  Cam- 
l)ridge,  Mass.,  and  show  the  bite  jumped  half  the  width  of  a  bicuspid. 
He  says:^  "I  made  a  plate  for  the  upper  arch  ....  thickened  only 
behind  the  front  teeth  where    depressions  were    made  to  receive  the 

Fig.  776. 


Cutter's  case  of  "jumping  the  bite." 

points  of  the  lower  incisors  .  .  .   .  and  held  firmly  in  place  by  wire 

clasps  encircling  the  first  molars I  made  several  plates  of  this 

character,  as  the  amount  to  be  gained  had  to  be  gradually  accomplished. 

The  patient  was  twelve  years  old,  and  but  one  permanent  second  molar 

had  erupted ;  when  the  work  was  completed  all  four  of  these  molars 

'  Oral  Deformities,  p.  84.  ^  International  Dental  Journal,  vol.  xv.  p.  355. 


LOWER  PROTBUaiON.  77-3 

had  erupted  and  interlocked  with  each  other.  The  result  was  that  the 
patient  could  comfortably  bring  her  jaws  together  only  as  they  had  been 
newly  related." 

Dr.  Talbot  says  :  ^  I  have  never  been  able  to  jump  the  bite  .... 
Were  such  a  thing  possible,  one  of  two  things  must  take  place.     First^ 
absorption  and  deposition  of  bone  cells  at  the  weakest  part  of  the  jaw ; 

Fig.  777. 


Cutter's  case  after  adjustment. 


namely  at  the  angle  ....  Second,  there  must  be  a  forward  movement, 
by  absorption,  of  the  condyle  in  the  glenoid  cavity." 

Fig.  778  shows  Prof.  Angle's  method  of  "jumping  the  bite"  bv 
means  of  a  spur  imbedded  in  the  lower  permanent  molar,  thus  com- 
pelling the  normal  closure  of  the  jaw. 


Fig.  778. 


Angle's  method  of  "jumping  the  bite." 

Class  10.  Lower  Protrusion. — Etiology. — This  irregularity  is  in 
most  cases  constitutional  and  may  be  attributable  to  the  following 
causes : 

(«)  Excessive  development  of  the  ramus  of  the  lower  maxilla,  as 
shown  in  Fig.  780 — constitutional. 

(6)  Excessive  development  of  the  body  of  the  lower  maxilla,  as 
shown  in  Fig.  781 — constitutional. 

(c)  The  habit  of  iinger-sucking,  in  which  the  finger  is  hooked  over 
the  lower  teeth — ac(|uired. 

'  Denial  Cosmos,  vol.  xxxiv.  p.  791. 


774 


ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 


(d)  Teeth  too  large  for  the  jaw  and  tliercforc  projecting  forward  of 
their  natural  position — indirect  heredity. 

((')  The  lower  protrusion  may  be  a]ii)arent  and  not  real,  owing  to 
lack  of  development  of  the  upper  maxilla.     This  may  be  due  to  nasal 


Fig.  779. 


Lower  protrusion  (Talbot). 

obstruction  (page  697)  or  to  the  injudicious  extraction  of  the  first  per- 
manent molars,  as  in  cases  of  apparent  upper  protrusion — acquired. 

(/)  It  may  result  from  the  npper  oral  teeth  having  erupted  back 
of  their  proper  position,  so  as  to  bite  inside  of  the  lower  incisors. 

{g)  Mal-occlusion  of  incisors. 

Fig.  780. 


Excessive  development  of  ramus  (Talbot). 


Treatment. — If  the  teeth  are  too  large  for  the  jaw,  room  may  be  made 
by  extraction  of  the  first  bicuspids,  nnless  teeth  posterior  to  them  are 
selected  on  account  of  caries. 

The  anterior  teeth  may  be  moved  back  by  the  labial  bow  shown  in 


LOWER  PROTRUSION. 


775 


Fig.  759.  Teeth  as  far  back  as  possible  should  be  selected  for  anchor- 
age. The  anterior  portion  of  the  bow  should  be  as  near  the  cutting 
edges  of  the  incisors  as  the  occlusion  will  allow  and  may  be  prevented 
from  sliding  toward  the  gum  by  one  or  more  small  hooks  over  the  cut- 
ting edges  of  the  teeth  or  by  bands  on  incisors  or  canines  with  lugs  or 
notches.  (See  Angle's  notches  in  retracting  appliance,  Fig.  771,  c,  c.) 
,  Dr.  C.  S.  Case  utilizes  the  upper  teeth  for  anchorage.  The  labial 
bow  previously  referred  to  is  applied  to  the  lower  teeth  and  has  a 
button  attached  to  it  near  the  canine  on  each  side.  From  this  button 
a  rubber  band  is  extended  to  a  similar  button  soldered  to  a  liand  on 
an  upper  molar,  as  far  back  as  possible.     The  tendency  of  this  is  to 

Fig. 781. 


Excessive  development  i.if  lindy  ( if  lower  maxilla  (Talbot). 

draw  the  upper  teeth  forward,  but  more  especially  to  draw  back  the 
anterior  lower  teeth  and  also  the  jaw  itself. 

Fig.  782  shows  Prof.  Angle's  appliance  for  this  purpose — "  the  large 


Fig.  782. 


Angle's  appliance. 


traction  screw  being  attached  to  clamp  bands  which  encircle  the  first 
lower  molars  and  the  angles  of  which  are  hooked  into  small  staples 


77G 


ORTHODONTIA    AS  AN  OPERATIVE  PROCEDURE. 


soldered  to  bands  upon  tlio  distal  angles  of  the  canines,  while  a  piece  of 
gold  wire  attached  by  solder  connects  these  bands  and  ])asses  in  front 
of  the  incisors."  This  cap  and  traction  bar  may  be  used  in  connection 
with   this  appliance  by  applying  the  latter  to  the  projection  in   front. 


Fio.  783. 


Allan  s  aiijihaiic'c. 

While  more  complicated  than  the  appliance  shown  in  Fig.  760,  it  must 
be  very  efficient. 

Constant  force  may  be  used  by  such  an  ap]>liance  as  is  shown  in 
Figs.  762  or  763.  The  form  of  plate  should  be  modified  for  the  lower 
arch. 

When  the  posterior  teeth  do  not  give  sufficient  anchorage,  an  exter- 
nal appliance  must  be  resorted  to.  The  cap  and  bit  shown  in  Fig.  766 
may  be  applied  to  the  lower  teeth,  or  Angle's  appliance  (Fig.  770)  may 
be  used  if  the  six  anterior  teeth  are  not  in  proper  alignment  in  respect 
to  each  other. 

If  the  protrusion  is  an  example  of  true  prognathism — that  is,  due 
to  the  lower  maxilla  being  larger  or  longer  than  the  upper  from  either 
of  the  causes  mentioned — external  force  alone  can  be  of  use. 

By  a  cup  of  metal  swaged  to  fit  the  chin  and  connected  by  rubber 
bands  with  a  cap  on  the  back  of  the  head,  as  shown  in  Fig.  783  or  in 
Fig.  784,  the  protrusion  may  be  reduced. 

How  this  is  accomplished  is  a  matter  of  dispute,  some  maintaining 
that  the  lower  maxilla  is  bent  at  the  angle  and  others  that  the  condyle 
is  pushed  back  in  the  glenoid  cavity.     Dr.  G.  S.  Allan  said  in  1878, 


LOWER  PBOTRUSIOX. 


777 


"  The  jaw  at  that  period  of  life  is  completely  developed  and  hardened 
....  consequently  any  efforts  that  may  be  made  will  not  affect  the 
jaw-bone  itself.  The  only  way  in  which  the  change  can  be  made  is  by 
pushing  the  jaw  back  into  the  glenoid  cavity.  .  .  .  Absorption  takes 
place  at  the  posterior  side  of  the  condyles,  with  filling  in  of  the  ante- 
rior."    Prof.  Angle  says,  "  The  object  is  by  continued  pressure  to  bend 

Fig.  784. 


Angle's  chin  retractor. 

the  jaw  at  the  angles,  but  only  in  very  young  patients  do  we  believe 
this  even  possible.     We  think  that  in   two  cases  we  have  succeeded." 

Ca.ses  sometimes  occur  in  which  the  fault  is  in  both  jaws ;  the  upper 
jaw  is  not  prominent  enough  while  the  lower  is  too  prominent,  and  the 
result  is  lower  protrusion.  Fig.  788  shows  such  a  case,  in  which 
the  fault  lies  partly  in  the  spaces  between  the  lower  bicuspids  and  the 
first  molar.  The  appliance  was  made  after  a  similar  one  by  Dr.  Case. 
It  consists  of  bands  on  the  loAver  canines  joined  by  a  wire  that  encircles 
the  incisors  and  the  ends  of  which  are  bent  into  hooks.  On  the  upper 
first  molars  are  cemented  bands  with  buccal  hooks.  A  strong  rubber 
band  was  extended  from  the  hook  on  the  lower  canine  to  the  hook  on 
the  upper  molar  band.  The  result  is  shown  in  the  second  cast  (Fig. 
789).  The  patient  was  lost  sight  of  after  that.  Just  what  changes 
took  place  is  uncertain, — whether  the  movement  was  wholly  of  the 
lower  teeth  or  whether  there  Avas  a  forward  movement  of  the  upper 
teeth  also.     The  writer  is  inclined  to  the  latter  opinion. 

AVhen  the  prognathism  is  apparent  and  not  real — (e)  and  (/) — the 
proper  treatment  is  to  move  the  upper  incisors  forward,  and  in  some 
cases  the  canines  also.  (For  appliances  adapted  to  this  purpose  see 
Figs.  716  and  717,  in  Class  6.) 


778  ORTHonoyTfA  as  an  operative  procedure. 

In  some,  lower  protrusion  from  this  cause  is  apparent  only  when 
the  patient  masticates.     Figs.  785  and  786  will  illustrate  this  condition. 

Fig.  785.  Fig.  786. 


Apparent  lower  protrusion— during  mastication.  The  patient's  natural  occlusion. 

If  the  npper  incisors  erupt  slightly  back  of  their  proper  position  the 
cutting  edges  will  occlude  with  the  cutting  edges  of  the  lower  incisors. 
As  eruption  continues  they  will  open  the  bite  (Fig.  786)  so  that  the 
patient  must  throw  the  lower  jaw  forward  in  order  to  occlude  the  bicus- 

FiG.  787. 


The  same  denture  after  treatment. 


pids  and  molars.  (See  Fig.  785.)  It  is  quite  possible  that  this  will 
result  in  a  permanent  protrusion  of  the  lower  jaw.  The  case  shown  in 
Figs.  785  and  786  was  an  argument  against  that,  however,  and  against 
the  possibility  of  "jumping  the  bite"  (see  page  770),  for  the  patient 
was  thirty  years  old,  and  never  protruded  his  lower  jaw  except  when 
masticating.  For  many  years  mastication  had  been  attended  with 
neuralgia  in  the  temporo-maxillary  articulation,  caused  by  the  unnatural 
strain,  yet  this  neuralgia  disappeared  entirely  after  the  upper  incisors 
and  canines  had  been  moved  forward  enough  to  close  in  front  of  the 
lower.     The  teeth  were  moved  by  the  split  plate  shown  in  Fig.  717. 

In  moving  forward  the  upper  anterior  teeth  in  cases  of  "  apparent 
lower  protrusion,"  such  as  shown  in  Fig.  785,  or  those  due  to  lack  of 
development  of  the  upper  maxilla,  it  sometimes  occurs  that  when  the 
cutting  edges  overlap  the  lower  incisors  the  crowns  have  a  very 
unnatural  slant  forward,  and  the  roots  need  to  be  moved  forward. 


L  0  WER  PR  0  TR  USION. 


779 


At  the  World's  Columbian  Dental  Congress  in  1893,  Dr.  C.  S.  Case 
presented  casts  and  appliances  for  this  oi)eration,  which  are  shown  in 
Chapter  XXY.,  Figs.  839,  842,  893,  and  895. 


Fig.  7 


Lower  protrusion  (fault  iu  both  jaws). 
Fig.  789. 


Result  of  reciprocal  appliance. 

By  this  means  the  entire  anterior  plate  of  the  alveolar  process  is 
moved  forward  with  the  roots  of  the  teeth  and  the  sunken  lip  restored 
to  its  natural  fidness. 

See  facial  contour  in  Figs.  840  and  843. 

Surgical  Treatment  of  Lower  Protrusion.— The  following  extracts  are 
from  a  description,  bv  Dr.  J.  W.  Whipple  of  St.  Louis,  of  the  case 
shown  in  Fig.  790. 

There  had  been  apparently  an  abnormal  growth  of  the  body  of  the 
maxilla  between  the  first  and  second  bicuspids  on  the  left  side  and  be- 
tween the  first  molar  and  second  bicuspid  on  the  right  side,  the  space 
separating  these  teeth  being  respectively  one-quarter  and  one-eighth  of 
an  inch,  causing  the  elongation  of  the  jaw  horizontally,  which  projected 
the  lower  teeth  a  qiwrter  of  an  inch  beyond  and  in  front  of  the  upper 
ones.      The  occlusion   was  destroyed.      This  elongation.  Dr.  Whipple 


780  ORTHODONTIA  AS  AN  OPERATIVE  PROCEDURE. 

states/  had  taken  place  between  1<S91  aiul  1896,  the  jiatient  being 
eighteen  years  of  age  wlien  he  first  saw  him.  Dr.  Whipple  advised  the 
patient  "  to  consult  Dr.  E.  H.  Angle,  who  first  suggested  the  advisabil- 
ity of  resorting  to  double  resection  in  this  case."  About  a  year  after- 
ward an  operation  was  j)erfornied,  and  about  a  quarter  of  an  inch  was 
removed  from  the  body  of  the  bone  on  each  side,  Dr.  V.  P.  Blair 
being  operator-in-chief. 

"An  incision  was  made  about  half  an  inch  in  length  along  the  base 
of  and  just  interior  to  the  lower  border  of  the  maxilla.  A  cross  incision 
was  made  of  the  same  length,  about  on  a  line  with  the  mental  foramen. 
The  centre  of  these  incisions  was  interior,  upon  the  borders  of  the 
neck.     The  muscles  and  other  integuments  were  now  detached  from  the 

Fui.  790. 


Lower  protiusiou.    (Dr.  Whipple's  case.) 

jaw-bone.  Dr.  Blair  had  devised  or  had  constructed  a  double  bone- 
saw,  consisting  of  two  saws,  four  inches  long,  attached  to  a  single  handle, 
and  so  adjusted  as  to  make  a  cut  in  the  clear  just  as  wide  as  the  space 
between  the  two  bicuspids  on  the  left  side.  The  sawing  was  done 
through  the  incision  from  and  through  the  internal  surface  of  the  bone 
from  the  upper  border  down  to  the  base.  No  vessels  were  ligated,  as 
the  hemorrhage  was  not  profuse  after  the  vessels  emptied  themselves. 
The  bone  was  cut  almost,  but  not  quite,  through.  No  attention  was 
given  to  the  inferior  dental  canal. 

*'  A  small  hole  was  now  drilled  through  the  bone  on  each  side  of  the 
cut,  near  the  lower  border,  for  the  reception  of  a  wire  ligature. 

"  The  second  right  bicuspid  having  been  previously  extracted,  the 
operation  just  described  was  repeated  on  the  right  side. 

'  Dental  Cosmos,  1898,  vol.  xl.  p.  552. 


LOWER  PROTRUSION. 


781 


"After  the  holes  were  drilled  the  remainder  of  the  sawing  was  done 
on  l)oth  sides,  and  the  two  small  sections  of  the  jaw  removed. 

"  Soft  copper  wire  ligatures  were  now  passed  through  the  holes  from 
the  external  surface.  These  were  crossed  on  the  internal  surface,  grasped 
with  a  pair  of  pliers,  and  twisted  until  the  several  parts  were  drawn 
together  at  the  lower  border,  forming  an  apparently  close  and  smooth 
abutment  of  the  opposing  ends. 

"  The  copper  wire  ligatures  proved  ineffectual,  so  clamp  bands, 
with  buccal  tubes,  were  applied  to  the  molar  and  bicuspid  on  one  side, 
and  to  the  molar  and  canine  on  the  other,  and  traction  screws  ex- 
tended through  the  tubes.  By  tightening  the  nuts  on  these  screws  the 
parts  of  the  jaws  were  brought  again  in  contact.  As  an  additional  pre- 
caution, '  bicuspid  fracture  bands '  were  placed  on  the  first  upper  and 
second  lower  bicuspid. 

Fig.  791. 


,ii;.,.  ;:i;iii)iiiiiiiiiiiiiiiiiiiiiiiiiii[i.iiiiiiim;;iii!i<i. 
Result  of  surgical  treatment  of  lower  protrusion.    (Dr.  Whipple's  case.) 

"A  figure-8  ligature  of  brass  wire  was  adjusted  to  the  little  knobs 
on  these  bands,  and  the  rear  fragment  was  firmly  ligated  to  the  upper 
jaw.  All  the  various  parts  were  held  absolutely  without  change  for 
five  weeks.  The  patient  lived  on  liquid  food  and  suifered  no  great  in- 
convenience physically. 

"A  four-tailed  plaster  bandage  was  adjusted  and  retained  without 
change  for  four  weeks." 

Within  eight  or  nine  weeks  the  ap]>Hances  were  removed  from  both 
sides,  osseous  union  having  taken  place.  Subsequently  some  of  the 
posterior  teeth  were  lengthened  by  means  of  gold  crowns,  and  the 
occlusion  restored.     The  final  result  is  shown  in  Fio;.  791. 

There  was  "an  entire  loss  of  sensation  in  the  lower  lip,  caused  by 
cutting  the  sensory  parts  of  the  inferior  dental  nerve. 

"The  pulps  of  the  middle  part  of  the  jaw  do  not  seem  to  have  been 
affected  at  all. 


782 


ORTHODONTIA   AS  AN   OPERATIVE  PROCEDURE. 


"The  gentleman's  appearance  is  greatly  improved.  No  one  would 
suspect  that  such  an  operation  had  been  perfonucd." 

Dr.  Angle  suggests  '  that  in  such  cases  the  chin  is  usually  very  promi- 
nent, so  that  there  is  more  or  less  lingual  inclination  of  the  lower  incisors 
and  that  the  section  of  bone  removed  should  be  wedge-shaped,  wider  at 
the  lower  border,  instead  of  with  parallel  sides. 

He  also  suggests  that  the  best  way  to  hold  the  parts  of  the  jaw  in 
place  would  be  to  make  a  cap  or  splint  of  metal  or  vulcanite  that  would 
fit  over  the  crowns  of  the  teeth  and  cement  it  in  place,  as  is  done  in 
the  fractures.  To  properly  construct  such  a  cap  or  splint,  plaster  models 
should  be  made  of  both  upper  and  lower  jaws,  then  sections  cut  out  of 
the  lower  one  so  that  the  teeth  could  be  properly  adjusted  to  the  upper^ 

Fig.  792. 


Vulcanite  or  metal  splint. 

taking  careful  measurements  of  the  parts.  On  this  reconstructed  model 
a  vulcanite  or  metal  splint  should  be  formed,  as  shown  in  Fig.  792. 
After  the  sections  of  the  jaw  are  removed  and  the  anterior  portion  forced 
back  in  contact  with  the  remainder,  the  splint  can  be  cemented  on  the 
teeth  to  hold  the  parts  firmly  in  correct  position. 

Class  11.  Double  Protrusion,  or  Protrusion  of  Both  Upper  and 
Lower  Teeth. — Occasionally  there  is  protrusion  of  both  upper  and 
lower  teeth  on  account  of  their  being  too  large  for  the  jaws.  The  lips 
appear  very  much  thickened,  or  are  unable  to  cover  the  teeth.  A  case 
of  this  character  (shown  in  Figs.  793  and  794)  was  treated  by  the  writer 
primarily  with  the  cap  and  bit,  such  as  are  shown  in  Fig.  766,  and 
secondarily  by  means  of  labial  bows,  shown  in  Fig.  795.  The  vulcanite 
bit  was  made  to  fit  over  the  anterior  part  of  the  bows  upon  both  upper 
^  Dental  Cosmos,  1898,  vol.  xl.  p.  635. 


DOUBLE  PROTRUSION. 


783 


and   lower  incisors  when   the  mouth  was  closed,  and  was  worn  except 
daring  school  hours,  the  patient  being  a  school-girl  aged  seventeen. 


Fig.  793 


Fig.  794. 


Double  protrusion.    (Corrected 


The  bows,  which  were  used  only  for  retention,  had  their  ends  secured 
in  tubes  on  bands  cemented  to  the  first  molars.  The  anterior  part  of 
the  upper  bow  rested  in  notched  bands  cemented  on  the  central  incisors. 
The  anterior  part  of  the  lower  bow  was  held  in  place  by  notched  bands 
on  the  lower  canines.     The  nuts  of  each  bow  were  tightened  every 

Fig.  795. 


Ketaining  appliance. 

morning  just  enough  to  make  up  for  the  movement  produced  by  the 
cap  and  bit  during  the  night.  There  were  thus  utilized  four  anchor 
teeth  in  each  jaw,  the  right  and  left  first  molars  and  second  bicuspid. 
This  was  sufficient  for  retention  of  the  six  anterior  teeth,  though  it 
would  not  have  been  sufficient  for  their  retraction.  If  these  anchor 
teeth  moved  forward  it  was  not  noticeable,  for  no  space  was  left  between 
the  first  and  second  molars,  though  tluit  fact  might  be  accounted  for  by 


784 


ORTHODONTIA  AS  AN  OPERATIVE  PROCEDURE. 


a  forward  iiioveinent  of  tlio  second  molars  of  their  own  accord.     Treat- 
ment of  this  case  was  begun  in  March,  1895,  and  in  August  the  six 


Fig.  796. 


B'jon. 


Double  protrusion. 


Afkr. 


anterior  teeth  had  been  moved  back  till  the  canine  touched  the  second 
bicuspids.     (Figs.  793  and  794.) 

The  same  bands  and  bows  were  worn  about  two  months  longer  for 
retention,  after  which  the  teeth  remained  firmly  fixed.  The  change  in 
the  contour  of  both  lips  was  most  marked.     (See  Figs.  796  and  797.) 


Fig.  7 


Saddle-shaped  arch. 

The  relation  of  these  cases  of  protrusion  to  facial  contour  is  dis- 
cussed at  length  in  Chapter  XXV. 

Class  12.  Constricted  Arch  (Saddle -shaped). — Etiology. — The 
constricted  arch  may  be  due  primarily  to  the  same  cause  as  the  pointed 
arch  ;  that  is,  («)  teeth  too  large  for  the  jaw,  or  (b)  the  first  permanent 
molar  being  forward  of  its  natural  position  on  account  of  premature  loss 


CONSTRICTED  ARCH.  785 

of  the  second  decidiious  molar,  (c)  Too  long-  retention  of  deciduous 
molars,  which  may  deflect  the  erupting  bicuspid  toward  the  median  line. 
In  either  of  the  first  two  cases  the  position  of  the  second  bicuspid 
in  eruption  will  determine  the  character  of  the  arch.  If  it  erupts  in 
an  exact  line  between  the  first  bicuspid  and  the  first  molar  it  will  crowd 
the  anterior  teeth  forward  (Fig.  799,  B),  but  if  it  erupts  to  the  slightest 
degree  to  one  side  of  the  direct  line,  it  wall  itself  be  crow^ded  out  of  the 
arch  lingually  or  buccally  (Fig.  799,  A ).    The  former  occurs  much  more 


%^ 


Fig.  799. 


Showing  crowding  of  bicuspid  or  canine,  or  both,  out  of  line  (Ottolengui). 

frequently.  When  the  canine  erupts  between  the  lateral  and  first  bicus- 
pid in  proper  alignment  it  will  gain  space  in  the  line  of  least  resistance, 
and  thus  crowding  the  first  bicuspid  will  force  it  back  against  the 
second,  which  in  turn  will  be  crowded  still  more  inside  the  arch,  thus 
producing  the  constricted  arch. 

If  the  canine  erupts  before  the  bicuspids,  it  forms  with  the  in- 
cisors a  firm  base  and  is  not  easily  moved  on  account  of  its  long  root. 
The  first  bicuspid  erupts  next,  and  the  second  bicuspid,  coming  later, 
will,  for  want  of  room,  be  crowded  inside  the  arch.  The  conditions 
may  not  be  the  same  on  both  sides  of  the  mouth.  The  crowding  may  be 
on  one  side  only,  producing  the  semi-saddle  arch,  or  varying  on  the  two 
sides  may  produce  the  semi-saddle  on  one  side  and  on  the  other  the 
semi-V,  or  the  canine  may  be  crowded  entirely  out  of  the  arch  (Class  7). 

Treatment. — The  treatment  of  the  constricted  arch  w^ill  de})end  upon 
w^hether  the  case  is  one  of  normal  teeth  and  a  small  arch  which  will 
admit  of  enlarging,  or  whether  the  arch  when  spread  would  be  too 
large  for  the  other  features. 

If  the  arch  will  admit  of  enlarging,  it  may  be  done  by  banding  the 
teeth   that  are   inside,  and  applying  a  jack-screw  or  Talbot  spring  be- 


786 


ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 


tween  them,  as  .shown  in  Fig.  741,  thus  forcing  them  outward  till  thcv 
are  in  proper  alignnu'nt. 

In  case  of  a  semi-saddle-shaped  arch  (Figs.  609  and  610) — that  is, 
one  in  which  the  irregularity  is  confined  to  one  side — three  or  more 
teeth  on  the  opposite  side  should  be  groujied  together  for  anchorage. 

If  the  case  is  an  aggravated  one  wiiich  will  not  admit  of  expansion, 
extraction  must  be  resorted  to — selecting,  of  course,  the  tooth  or  teeth 
most  out  of  line. 

Class  13.  Lack  of  Anterior  Occlusion. — Etiology. — This  irregu- 
larity is  generally  of  constitutional  origin,  and  may  be  due — 

(a)  To  lack  of  development  of  the  ramus  of  the  lower  maxilla. 
(See  Fig.  800.) 

(6)  To  lack  of  development  of  the  anterior  portion,  or 

(c)  To  hypertrophy  of  the  posterior  portion  of  the  alveolar  process. 

id)  It  may  be  acquired  by  thumb-sucking,  as  shown  in  Fig.  801. 

The  jaws  being  held  apart  thus  pre- 
vents normal  eruption  of  the  anterior 
teeth  and  consequent  development  of 

Fig.  SOI. 


Fig.  800. 


Lack  of  anterior  occlusion  (Talbot). 


Lack  of  anterior  occlusion  caused  by  thumb- 
sucking  (Talbot). 


the  anterior  portion  of  the  alveolar  ridge,  or  allows  excessive  develop- 
ment of  the  posterior  portions. 

{e)  It  may  be  acquired  from  the  habit  of  mouth-breathing,  which, 
relieving  the  molars  from  pressure,  permits  abnormal  development  of 
the  alveolar  process  containing  them.  A  case  recently  occurred  in 
the  writer's  practice  which  illustrates  this.  The  patient  was  fifteen 
years  of  age,  and  was  a  mouth-breather.  There  Avas  a  space  of  an 
eighth  (jf  an  inch  between  the  cutting  edges  of  the  upper  and  lower 
incisors,  wdiile  three  or  four  years  before  she  could  bite  off  a  thread 
with  these  same  incisors. 

That  the  opening  w^as  not  caused  solely  by  the  eruption  of  the 
second  molars  was  shown  by  the  fact  that  the  first  molars  occluded 
equally  well.     The  case  was  reduced  by  grinding  the  molars  till  the 


LACK  OF  ANTERIOR   OCCLUSION.  1^1 

incisors  touched,  yet  not  enough  of  the  teeth  was  removed  to  render 
them  sensitive.     Figs.  802  and  803  illustrate  this  case. 

Fig.  802. 


Lack  of  anterior  occlusion. 


Lack  of  anterior  occlusion  is  often  accompanied,  as  shown  in  these 
figures,  by  other  irregularities,  which  may  be  treated  subsequently. 


Fig.  803. 


First  bicuspid  removed  to  make  room  for  canine  ;  occlusal  defect  remedied  by  grinding. 


(/)  Fig.  804  shows  a  case  due  to  lack  of  development  of  the  inter- 
maxillary bone.     When  nine  years  old  both  upper  central  incisors  were 

Fig.  804. 


Lack  of  development  of  intermaxillary  bone. 


knocked  out  without  fracturing  the  teeth  or  the  process.  The  writer 
replanted  the  teeth  after  removing  the  pulps  and  filling  the  canals  with 
gutta-])ercha.  The  teeth  at  that  time  were  about  two-thirds  erupted, 
and  did  not  erupt  any  farther.     The  growth  of  the  process  surrounding 


788  ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 

these  teeth  was  jirrcstcd  and  lliat  ol'  the  iiitcnnaxillai'y  bone  and  ad- 
jacent part  of  the  uj)i)('r  maxilla  retarded  as  shown.  The  cast  was 
made  at  the  age  of  sixteen,  at  which  time  one  of  the  teeth  was  still  so 
firm  as  to  permit  the  insertion  of  a  gold  filling,  while  the  other  was  so 
loose  from  resorption  of  the  root  that  it  was  extracted.  The  socket 
was  deepened  and  enlarged  and  a  tooth   implanted. 

The  infincnce  of  heredity  may  he  prominent  in  this  deformity,  several 
meml)ers  of  one  family  presenting  the  condition. 

AMiile  this  irregularity  is  generally  of  constitutional  origin  it  is  not 
always  dtjveloped  till  the  eruption  of  the  second  and  tliii-d  molars,  or,  if 
slight,  while  the  first  molar  is  the  posterior  tooth,  is  increased  in  de- 
gree by  the  eruption  of  the  second  and  the  third  molars,  just  as  a  pair 
of  dividers  kept  open  a  certain  distance  by  a  prop  two  inches  from  the 
joint  will  be  opened  farther  if  a  prop  of  the  same  height  be  placed 
between  the  first  one  and  the  joint. 

The  writer  has  been  fortunate  enough  to  be  able  to  watch  the  devel- 
opment, in  its  later  stages,  of  such  a  case.  The  occlusion  at  the  first 
visit  of  the  patient  was  entirely  with  the  second  molars,  and  the  cut- 
ting edges  of  the  upper  and  lower  incisors  were  a  quarter  of  an  inch 
apart.  As  the  patient  had  suffered  during  childhood  from  what  she 
called  "  bone  disease "  she  was  afraid  to  submit  to  any  treatment  for 
bringing  the  anterior  portion  of  the  jaws  nearer  together.  Gold  crowns 
were  placed  over  the  lower  first  molars,  to  occlude  with  upper  teeth, 
and  increase  the  power  of  mastication.  Within  two  or  three  years 
afterward  the  third  molars  erupted  and  opened  the  jaws  to  such  an 
extent  that  the  gold  crowns  lacked  more  than  a  sixteenth  of  an  inch 
of  touching  the  upper  teeth.  This  case  was  undoubtedly  due  to  the 
shortness  of  the  ramus  of  the  lower  jaw. 

Treatment. — The  simplest  treatment  of  such  cases  is  to  grind  down 
the  cusps  of  the  occluding  teeth.  In  simple  cases  this  can  be  done  so  as 
to  enable  the  incisors  to  bite  upon  each  other.  (See  Figs.  802  and  80.3.) 
The  third  molars  may  interfere  so  much  that  their  extraction  will  be 
indicated.  By  the  use  of  articulating  paper  the  occluding  points  whi(;h 
need  grinding  may  be  easily  located. 

In  some  cases  there  may  be  a  mal-occlusion  of  the  cusps  only,  so 
that  grinding  them  away  will  be  sufficient,  while  in  other  cases  a  con- 
siderable portion  of  the  tooth  must  be  ground  away.  Prof.  Guilford 
suggests  grinding  as  much  as  possible  without  causing  too  great  pain, 
and  then  administering  an  anesthetic  and  continuing  the  grinding. 
"  The  sensitiveness  of  the  exposed  dentin  may  afterward  be  obtunded 
by  repeated  applications  of  either  zinc  chlorid,  caustic  potash  [potas- 
sium hydroxid],  or  silver  nitrate.  Where  neither  of  these  will  avail 
sufficiently,  it  may  be  advisable  to  devitalize  the  pulps  of  two  or  more 


LACK  OF  ANTERIOR   OCCLUSTOX. 


789 


of  the  teeth  most  interfering  with  occlusion,  and  then  continue  grind- 
ing until  the  necessary  cliange  is  eifocted."  ^ 

The  writer  has  lately  applied  cataphoresis  successfully  after  having 


Fig.  805. 


Kingsley's  appliance  for  forcing  molars  into  their  sockets. 

ground  the  teeth  away  till  they  were  quite  sensitive.    The  operation  was 

thus  continued  two  or  three  times  in  succession  till  the  required  reduction 

was  eiFected. 

Fio.  806. 


Kingsley's  appliance  for  forcinc  molars  into  their  sockets. 

Bv  the  use  of  a  chinpiece  and  cap  on  the  head  similar  to  that  shown 
in  Figs.  783  and  784  for  reducing  lower  protrusion  the  anterior  por- 
tion of  the  jaws  may  be  closed.     There  are  three  possible  solutions  as 

'  Orthodontli,  'Jd  ed.,  p.  195. 


•00 


ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 


Fig.  807. 


to  how  the  change  is  effected — (1)  filling  up  of  the  glenoid  cavity,  (2) 
elongation  of  the  condyle,  or  (3)  the  forcing  of  the  molars  into  their 
sockets.  The  latter  is  the  most  plausible  explanation,  judging  from 
experience  in  cases  of  Class  4. 

Fig.  805  shows  an  appliance  devised  by  Dr.  Kingsley  for  forcing 
the  upper  molars  into  their  sockets,  and  described  by  him  as  follows  : 
''  A  frame  covered  the  bicuspids  and  molars  of  the  upper  jaw,  with  arras 
coming  out  of  the  corners  of  the  mouth  and  extending  along  the  cheeks 
to  a  point  exactly  opposite  the  centre  of  the  pressure  required  within 
the  mouth ;  a  small  wire  passed  in  front  of  the  incisors  to  keep  them 
from  springing  forward  and  two  elastic  straps  connected  this  frame  with 
the  skull-cap  exactly  as  seen  in  Fig.  806.  Both  these  elastics  were  re- 
quired, partly  to  prevent  any  tendency  of  the  recently  moved  incisors 
from  carrying  the  whole  apparatus  forward,  but  particularly  to  keep  the 
proper  balance  of  the  skull-cap,  the  strain  of  either  elastic  alone  having 
a  tendency  to  pull  it  out  of  place." 

Class  14.  Excessive  Overbite. — Etiology. — Overbite  as  illustrated 
in  Fig.  807  is  due  (^?)to  hick  of  development  of  the  posterior  portions  of 

the  jaws  and  process,  or  (6)  to  excessive 
development  of  the  anterior  portions 
of  the  same  so  that  the  upper  incisors 
and  canines  close  entirely  over  the 
lower  and  hide  them  from  view,  while 
the  cutting  edges  of  the  lower  teeth 
impinge  either  upon  the  necks  of  the 
upper  or  upon  the  gums  behind  them, 
sometimes  to  such  an  extent  as  to 
penetrate  the  gum  tissue. 

This  condition  is   often  associated 
with  other  irregularities  ;  particularly 
protrusion  of  the  upper  incisors,  of 
which  it  may  be  the  cause. 
While  many  cases  may  be  improved  by  grinding  the  cutting  edges 
of  the  lower  incisors,  it  is  not  always  sufficient,  as  the  relative  condi- 
tions  remain  the  same. 

The  treatment  of  such  cases  consists  in  («)  forcing  the  upper  anterior 
teeth  up  into  their  sockets,  (6)  depressing  the  lower  anterior  teeth  in 
their  sockets,  (c)  causing  the  bicuspids  and  molars  to  erupt  far  enough 
to  overcome  the  deformity,  or  ((/)  all  three  movements  combined. 

If  the  whole  fault  lies  with  the  upper  incisors  and  canines  from  their 
having  erupted  too  far,  they  may  be  forced  up  into  their  sockets  by  an 
appliance  such  as  is  illustrated  in  Fig.  808,  reported  by  Dr.  Kingsley  in 
1866.     It  consisted  of  a  gold  frame  over  the  cutting  edges  of  the  in- 


Overbite  (Talbot). 


EXCESSIVE  OVERBITE. 


■91 


cisors  and  canines.  From  this  frame  a  post  projected  from  each  corner 
of  the  mouth,  and  from  these  posts  strips  of  brass  (detachable)  extended 
upward  and  backward  and  were  connected  by  elastic  ligatures  with  a 


Fig.  808. 


Kingsley's  appliance. 

cap  on  the  back  of  the  head.  It  will  be  noticed  that  the  attachment  to 
the  cap  is  above  and  forward  of  the  ear.  The  cap  should  be  so  adjusted 
as  to  bring:  the  pressure  as  much  as  possible  in  a  line  with  the  roots 
unless  it  be  desirable  to  move  the  crowns  backward  at  the  same  time,  in 
which  case  attachment  to  the 
cap  may  be  made  below  the 
ear  as  well  as  above  it,  as 
shown  in  Fig.  766. 

Figs.  809  and  810  show  a 


Fig.  810. 


Case's  ai)pliaiice. 


case  of  overbite  treated  by  Dr.  C.  S.  Case,  in  which,  he  says,  "  the  jaws 
were  opened  by  permanently   lengthening   the   posterior  teeth."     His 


792 


ORTHODONTIA   AS  AN  OPFJIATIVE  PROCEDURE. 


metlio<l  of  treatment  lu'describes  as  follows  :  "  I  inserted  a  simple  black 
rubber  plate  that  covca'cd  the  roof  of  the  mouth  and  possessed  a  thick- 
ened portion  in  front  to  receive  the  thrust  of  the  six  lower  anterior 
teeth  ....  The  posterior  teeth  were  thus  prevented  from  forcible 
occlusion  until  Nature  had  produced  in  them  a  sufficient  growth  and 
fixed  them  permanently  in  their  extended  positions." 

Unless  such  a  plate  rests  on  the  inclined  surfaces  of  the  canines  (and 
incisors  also,  in  some  instances)  the  force  in  biting  will  cause  it  to  injure 
the  soft  parts  on  -which  it  rests.  To  prevent  it  from  moving  the  canines 
outward  clasps  should  be  extended  around  them,  or  the  plate  should  be 
provided  with  a  labial  bow  and  clas])s  or  extensions  of  the  plate  around 
the  first  or  second  molars,  similar  to  the  plate  shown  in  Fig.  762,  except 
that  the  ])late  should  extend  forward  to  the  incisor  teeth.  The  bow 
will  ])revent  any  forward  movement  of  the  u])per  incisors,  and  may 
even  be  used  to  reduce  their  prominence  by  pressure  upon  them. 

Dr.  Cutter^  of  Cambridge,  Mass.,  describes  a  case  in  which  the 
posterior  teeth  were  lengthened  by  a  similar  plate,  and  the  lower  jaw 
brought  forward  at  the  same  time,  by  so  shaping  the  plate  that  the 
lower  incisors  bit  upon  an  inclined  plane.    (See  Figs.    776  and  777.) 

Dr.  Andrews  ^  describes  a  similar  case  as  follows  :  "  I  had  a  patient 
a  little  over  twelve  years  of  age,  the  cutting  edge  of  whose  lower 
incisors  touched  the  upper  gum  so  as  to  irritate  it.  A  platform  plate 
such  as  Dr.  Cutter  describes  was  worn   for  about  two  months.     The 

Fig.  811. 


Writer's  appliance  for  depressing  lower  incisors. 

lower  centrals,  laterals,  and  canines  struck  against  the  plate  and  allowed 
the  bicuspids  and  molars  to  elongate.  After  a  time  1  found  there  was 
one-eighth  to  a  quarter  of  an  inch  space  between  the  lower  incisors  and 
the  upper  gum  in  closing  the  mouth." 

Fig.  695  shows  how  the  writer  elongated  upper  and  lower  bicus- 
pids and  molars  so  that  they  could  occlude.  The  same  plan  might  be 
followed  with  all  of  the  bicuspids  and  molars  at  the  same  time,  while 
the  jaws  are  held  open  with  such  a  ])late  as  that  shown  in  Fig.  810. 

1  International  Dental  Journal,  vol.  xv.  pp.  353-355.  ''  Ibid.,  pp.  382,  383. 


EXCESSIVE  OVERBITE.  793 

Fig.  811  shows  a  jilan  for  forcing  lower  incisors  into  their  sockets. 
A  metal  cap  is  swaged  to  fit  over  the  occlusal  edges.  To  this  is  sol- 
dered a  wire  which  extends  out  of  the  corners  of  the  mouth  and  is  bent 
into  hooks  at  each  end.  From  these  hooks  rubber  bands  extend  to  a 
chinpiece.     To  prevent  this  chinpiece  from  sliding  forward  it  is  neces- 

FiG.  8T2. 


Davenport's  appliance  for  raisin<i  the  l)ite. 

sarv  to  extend  a  tape  from  it  around  the  patient's  neck.     This  appliance 
Avas  suggested  by  the  interdental  splint. 

Fig.  812  show's  an  appliance  for  raising  the  bite,  by  Dr.  W.  S. 
Davenport,  exhibited  at  a  meeting  of  the  American  Dental  Society  of 
Europe,  Aug.  5,  1895.     "  The  means  employed  for  correcting  the  irreg- 

FiG.  813. 


Case's  appliance  for  raising  the  bite. 

ularity  was  to  in.sert  a  bridge  appliance,  which  was  fastened  by  means 
of  gold  caps  to  the  second  molars,  and  brought  forward  a  few  lines 
above  the  molars  and  bicuspids,  resting  with  a  gold  saddle  on  the  six 
front   teeth.     In    two  weeks  the  arch  was   spread   and  tlie  teeth  were 


704  ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 

drawn  up  to  a  normal  jxjsition  l)y  the  use  of  liuaturos  which  were 
h)(i|)C(l  around  the  bicuspids  and  niohirs,  and  fastened  at  the  lingual 
surliice,  then  tied  to  the  masticating  surface  of  the  l)ridge  above."  ' 

Fig.  813  shows  an  appliance  of  similar  character  devised  In-  Dr. 
C.  S.  Case.^  The  object  of  the  appliance  is  to  depress  the  lower  incisors 
in  their  sockets,  and  raise  the  bicuspids,  and  first  molar  also,  when 
possible,  so  as  to  change  the  whole  line  of  occlusion  and  open  the  bite. 

On  each  molar — first  or  second  according  to  the  age  of  the  patient 
— is  placed  a  hollow^  crown,  on  the  buccal  surface  of  which  is  soldered 
an  open  tube  or  trough,  opening  upward.  On  each  bicuspid  is  soldered 
a  band  with  a  buccal  hook  pointing  downward,  also  on  the  first  molar 
if  the  second  has  been  used  for  supporting  the  hollow  crown.  On  the 
incisors  are  cemented  bands  with  hooks  turned  upward.  A  labial  bow 
of  elastic  German  silver  or  piano  Mire  has  its  ends  inserted  in  the 
troughs  of  the  hollow  crowns,  its  front  resting  above  the  hooks  on  the 
incisors  and  its  sides  pressed  under  the  hooks  on  the  bicuspids  and 
first  molar.  The  action  is  such  as  to  depress  the  incisors  and  elevate 
the  bicuspids  and,  if  possible,  the  first  molar  also.  The  hollow  crown 
should  be  high  enough  to  open  the  bite  the  required  distance. 

Class  15.  Separation  in  the  Median  Line. — The  simplest  treatment 
of  this  irregularity  is  to  draAv  the  centrals  together  with  a  rubber  band  or 
with  twusted  silk  or  linen  ligatures  passed  two  or  three  times  around  the 
teeth.     They  can  be  retained  by  a  wire  band  passing  around  both  teeth. 

In  some  cases  it  is  better  to  cement  on  the  lateral  incisors  bands 
with  tubes  on  the  labial  surfaces  and  draw  them  toward  each  other  by 
means  of  a  long  drag-screw,  as  shown  in  Fig.  814. 

Fk;.  814. 


Appliance  for  regulation  and  retention. 

The  same  appliance  serves  for  retention  by  adding  cement  to  the 
screw  behind  the  nut  to  prevent  its  loosening.  The  advantage  of  this 
plan  is  that  the  space  is  left  next  to  the  canines  instead  of  between 
the  centrals  and  laterals,  and  also  that  the  centrals  will  be  more  easily 
retained  in  their  new  position  if  they  are  supported  by  the  laterals.  If 
the  central  incisors  are  far  apart  and  the  roots  are  parallel,  they  will 
slant  too  much  when  moved  together  as  described.  It  is  necessary 
1  Dental  Review,  Feb.  15,  1896,  p.  126.  ^  Ibid.,  Dec.  1895,  p.  867. 


MOVING   THE  ROOTS  OF  TEETH. 


795 


to  also  move  the  roots  of  these  teeth ;  the  method  of  performing  that 
operation  is  described  in  the  following  section. 

Moving  the  Roots  of  Teeth. 

In  the  foregoing  methods  of  moving  the  teeth  the  apex  of  the  root 
remains  stationary  and  the  crown  swings  from  that  point  like  a  pen- 
dulum. In  most  cases  that  is  the  only  movement  necessary,  in 
others  it  is  the  only  movement  possible,  yet  in  many  cases  it  is  very 
undesirable. 

The  first  published  appliance  for  moving  the  apices  of  the  roots  of 
teeth  was  that  described  bv  Dr.  J.  N.  Farrar.'     (See  Figs.  815  to  818.) 


Fig.  815. 


Fk;.  816. 


Fio.  817. 


Fig.  818. 


-^^-^ 


Fig.  819. 


The  central  incisors  were  separated  as  shown   in  Fig.  815,  the  roots 
being  parallel.     In  drawing  them  together  by  a  clamp  band  (/>)  the 
teeth  tilted  toward  each  other  until  they  touched  at 
the  mesio-incisal  angles  (/,  Fig.  816).   Up  to  this  time 
the  apices  of  the  roots  were  practically  the  fixed  points, 
and  the  alveolar  process  between  the  roots  was  con- 
densed and  absorbed  as  the  teeth  moved.     As  soon 
as  the  crowns  touched  eadi  other  at  tlio  mesio-incisal 
angles  these  became  the  fixed  points,  and,  as  the  power 
was  still  continued  at  the  necks  of  the  teeth,  the  roots  began  to  move 
'  Dental  Cosmos^,  vol.  xxiv.  p.  190. 


Incisor  guide. 


796 


ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 


till  thev  wort'  practically  parallel  (Fig.  818).  To  prevent  the  crowns 
sli(lini>:  past  each  other  and  overlapping,  a  guide  was  constructed  as 
sliown  in  Fig.  819.     The  same  ap[)liance  will  serve  for  retention. 

If  after  extracting  a  crowded  lower  incisor  the  teeth  on  each  side 
of  the   space  are   found   to   lean    toward   each   other,   as   in    Fig.  820, 

Fig.  820. 


Appliance  for  moving  roots  of  lower  incisor  and  cuspid. 

the  roots  may  be  moved  toward  each  other  so  that  the  crowns  will 
be  parallel  to  each  other.  Dr.  C.  S.  Case  has  devised  an  appliance 
for  this  purpose,  shown  in  Figs.  821  and  822.  Bands  are  fitted 
to  the  teeth  on  each  side  of  the  space,  and  sometimes  to  the  second 
tooth  also.  From  these  bands  stiff  bars  extend  downward  parallel 
with  the  surface  of  the  gum  from  an  eighth  to  a  third  of  an  inch  below 


Fig.  821. 


Fig.  822. 


Appliance  for  moving  roots. 

the  margin.  On  the  lingual  surface  similar  bars  extend  about  the 
same  distance.  On  the  free  ends  of  the  bars  are  soldered  hooks  or 
headed  pins,  so  that  a  rubber  band  or  a  ligature  can  be  extended 
from  one  labial  bar  to  the  other,  and  from  one  lingual  bar  to  the 
other.  The  direction  of  force  is  thus  brought  low  enough  to  move 
the  roots  as  well  as  the  crown  of  the  teeth.  Suture  wire  may  be 
substituted  for  the  rubber  band  or  ligature  for  retention. 

In  some  cases  of  upper  protrusion  the  alveolar  process  is  so  promi- 
nent that  when  the  crowns  of  the  teeth  are  moved  back  to  the  desired 


MOVING    THE  ROOTS  OF  TEETH. 


797 


position  the  roots  have  not  moved  with  them,  and  the  upper  lip  is 
still  too  prominent.  So  also  in  some  cases  the  palatal  portion  of  the  al- 
veolar ridge  is  so  dense  that  it  does  not  yield  readily,  and  as  the  crowns 
move  backward  the  edge  of  the  process  acts  as  a  fulcrum  and  the  ends 
of  the  roots  move  forward.     The  prominence  of  the  lip  is  thus  increased. 

In  the  World's  Columbian  Congress,  1893,  Dr.  C.  S.  Case  showed 
casts  and  models  of  such  cases  and  appliances  by  which  the  roots  and 
the  whole  anterior  alveolar  process  can  be  moved  back  and  the  promi- 
nence of  the  upper  lip  reduced  to  a  normal  contour.  For  illustrations 
and  descriptions  of  this  operation  the  reader  is  referred  to  Chapter 
XXY.,  and  especially  to  Figs.  847,  853,  854,  855,  896,  and  897. 

Fig.  823  shows  Dr.  Farrar's  appliance  for  moving  forward  the 
roots  of  incisors  by  working  on  the  lingual  side  of  the  arch.     "  The 


Fiirrai's  appliance  for  moving  incisor  roots  forward. 


Fig.  S24. 


base  of  support  is  a  transpalatal  screw-jack,  anchored  by  two  clamp 
bands  that  embrace  the  side  teeth  ;  from  this  jack  to  the  posterior  sides 
of  the  necks  of  the  incisors  and  lying  close  to  the  sides  of  the  arch  are 
two  other  scrcAV-jacks  to  press  against  these  front  teeth.  To  hold  these 
jacks  upon  them,  each  incisor  has  upon  it  a 
broad  ferrule  (cemented)  with  a  U-shaped  lug 
on  the  lingual  side,  near  the  gum  (see  F,  in 
the  lower  part  of  Fig.  823),  in  which  a  bar 
connecting  the  anterior  ends  of  the  jacks  rests. 
To  hold  firmly  the  end  of  the  crown  of  each 
incisor,  and  prevent  them  from  moving  for- 
Avard  when  these  iacks  are  set  at  work  against 

*'  •11  Showing  attachment  of  cross- 

the  necks  of  the  teeth,  the  ends  are  tied  to  the  bar. 

transpalatal  jack  by  two  wire  cords  connecting 

with  a  crossbar  lodged  in  other  U-shaped  lugs  soldered  to  the  labial  side 


798 


ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 


of  the   ferrules  near  the  ends  of  tlu;    teeth,  as    represented   hv    Fig, 
824." 

Fig.  825  shows  another  of  Dr.  Farrar's  appliances  for  the  same 
purpose,  which  makes  use  of  a  labial  bow  for  retaining  the  ends  of 


Fig.  825. 


Farrar's  appliance  for  moving  roots  forward. 


the    incisors,   and   omits    the    transpalatal   jack,   thus    simplifying   the 

apparatus. 

Fig.  826  shows  Dr.  Farrar's  appliance  for  drawing  back  the  roots 

of  upper  incisors.  "  The  crowns 
are  stayed  by  an  inside  rectan- 
gular frame  resting  in  U-shaped 
lugs  at  the  ends  of  the  crowns 
and  braced  against  nuts  soldered 
to  two  anchor  clamp  bands  on 
the  side  teeth.  The  roots  are 
drawn  back  by  a  labial  bow,  at- 

FiG.  827. 


Farrar's  appliance  for  moving  roots  back. 


Cross  section. 


tached  to  the  clamp  bands  by  screws.     Fig.  827  shows  a  cross  section 
of  such  an  appliance. 


IMMEDIATE  MOVEMENT  OF  TEETH. 


799 


Immediate  Movement  of  Teeth. 

The  forcible  rotation  of  a  tootli  bv  the  forceps  was  recommended  by 
Mr.  John  Tomes.'  He  said  the  operation  had  been  frequently  performed 
by  himself  and  others,  without  devitalizing  the  pulp  except  in  one  hos- 
pital case  ;  that  the  best  age  for  the  operation  was  eight  or  nine  years  ; 
that  he  had  performed  it  for  patients  thirteen  years  of  age  and  for  one 
patient  of  fifteen.  The  operation  has  been  performed  by  many  since 
then,  and  for  older  patients  also,  being  preferred  by  some  to  the  longer 
but  less  painful  plan  usually  followed. 

The  beaks  of  the  forceps  should  be  carefully  fitted  to  the  neck  of 
the  tooth,  which  should  be  protected  by  sandpaper,  emery  cloth  or  lead 
foil.  Tomes  recommends  that  in  some  cases  the  tooth  be  rotated  half 
way  at  first,  then  allowed  to  rest  for  a  couple  of  weeks  before  being  ro- 
tated to  place.  The  operation  is  confined,  of  course,  to  teeth  with  straight 
conical  roots.  Even  a  slight  curve  in  the  root  such  as  is  frequently 
found  with  the  lateral  incisor  would  render  the  operation  impossible. 

Immediate  Regulating-  of  Inlocked  Teeth. — Dr.  L.  C.  Bryan ''  has 
advocated  the  immediate  movement  of  single  teeth,  situated  inside  the 

Fiu.  828. 


arch,  especially  canines  and  laterals.  The  following  is  his  description 
of  the  operation  :  "  The  treatment  which  I  have  finally  adopted  is  to 
inject  cocain  and  either  partially  cut  away  the  thick  intervening  alveolar 
process  with  drills  and  fissure  burs,  or,  when  the  process  is  thin,  bodily 
wedge  the  outer  alveolar  wall  away  with  a  half-round  wedge-shaped 
chisel,  by  inserting  the  point  of  the  instrument  between  the  crown  and 
the  bone  and  forcing  it  up  along  the  root  until  enough  space  is  secured 
for  the  tooth  to  be  brought  out  into  place  outside  the  lower  tooth.  This 
'  Tomes,  Denial  Sunjery,  2d  ed.,  p.  1G2.         '^  Dental  Review,  1892,  vol.  vi.  p.  859. 


800 


ORTHODONTIA  AS  AN  OPERATIVE  PROCEDURE. 


latter  I  fnrinorly  ivccoiupHshod  by  })r('ssiii(;'  tlic  wi'dj^e-shaped  instrument 
or  the  inner  beak  of  a  suitably  formed  ibreeps  up  aloii<>;  the  liniijual  sur- 
face of  the  tooth  until  the  crown  was  forced  outward  sutliciently  to  be 
firmly  grasped.     It  was  then  brought  gradually  out  into  place." 

Another  and  better  plan  was  by  the  use  of  forceps  specially  made 
for  the  purpose,  shown  in  Fig.  828. 

Following  is  a  description  of  an  o|)crati()n  by  Dr.  l>ryan,  at  the 
World's  Columbian  Dental  Congress  in  Chicago,  August,  189.3,  from 
the  report  of  the  Committee  on  Clinics  : '  "  The  patient,  a  fifteen-year- 
old  girl,  had  a  right  upper  lateral  incisor  locked  behind  the  lower 
incisors  with  sufficient  space  between  the  upper  central  and  canine  for 
immediate  regulation.  Cocain  was  injected  and  a  perpendicular  incision 
was  made  with  a  small  circular  saw  through  the  gum  and  half  through 
the  alveolar  septum  on  both  sides  of  the  root  of  the  lateral  from  the 
apex  of  the  root  to  the  crown  of  the  tooth.  A  three-inch  flat  steel 
guard,  lined  on  the  gum  side  with  rubber  ^^g-  of  an  inch  thick,  was 
fitted  to  the  curve  of  the  gum  and  formed  a  rest  for  the  long,  round 
front  beak  of  the  forceps ;  the  other  beak  rested  against  the  distal  wall 
of  the  lateral  up  to  the  gum.  With  slight  pressure  the  connection  of 
the  tooth  with  the  distal  alveolar  wall  was  severed,  and  the  tooth  came 

Fig.  829. 


Immediate  movement  of  bicuspid  (Cunningham). 

easily  forward  to  its  place  in  the  arch  in  front  of  the  lower  teeth,  bring- 
ing with  it  the  front  wall  of  the  alveolus,  firmly  attached  to  the  root 
and  ready  to  heal  quickly  and  reunite  with  the  neighboring  borders  of 
alveolus.  The  apex  of  the  root  was  not  disturbed  in  its  position,  so  that 
the  nerve  and  vessels  would  remain  intact,  as  will  always  be  the  case 
if  the  operation  is  correctly  and  carefully  performed." 

Moving-   Several  Teeth  by  the   Immediate   Method. — Dr.   Geo. 
Cunningham  of  Cambridge,  England,  began  the  use  of  this  method  in 
^  Transactions,  vol.  ii.  p.  997. 


IMMEDIATE  MOVEMENT  OF  TEETH. 


801 


1886  by  forcing  with  the  forceps  an  inlocked  bicuspid  into  the  position 
of  a  molar  which  he  had  just  extracted.  The  tooth  became  firm  in  its 
new  position,  but  the  pulp  did  not  survive  the  operation.  Figs.  829  and 
830  were  made  from  photographs  of  casts  of  the  case,  before  and  after 
treatment. 

Fh;.  S80. 


Immediate  movement  of  bicuspid  (Cunningham).    After  treatment. 

Figs.  831  and  832  show  casts  of  a  case  in  which  he  forced  five  teeth 
into  new  positions.  The  following  is  his  description  :  "  The  patient  hav- 
ing been  anesthetized  (nitrous  oxid  and  ether),  the  molar  was  extracted, 
and  after  fracture  of  the  alveolar  process  between  the  teeth  both  bicuspids 


Fig.  832. 


Immediate  movem.ent  of  five  teeth  (Cunningham). 

were  luxated  backward  by  means  of  Physick's  forceps.  The  canine  and 
lateral  incisor  were  similarly  treated  with  the  additional  help  of  guarded 
ordinary  forceps.  On  endeavoring  to  luxate  the  central  incisor,  owing 
to  a  curved  and  distorted  root,  it  slipped  down  between  the  beaks  of  the 
forceps,  and  thus  became  completely  dislocated  from  its  socket  and  all 

51 


802 


ORTHODONTIA   AS  AN   OPERATIVE  PROCEDURE. 


its  normal  attachnionts  ....  Considerable  force  had  to  be  exerted  to 
thrust  it  into  its  new  position."     The  teeth  were  lig:ated,  etc. 

Among  other  directions  he  gives  the  following:  "All  being  ready,  cut 
the  alveolar  process  with  a  thin  saw  \  of  an  inch  to  1|^  inches  in  diameter, 
not  thicker  than  note-paper,  into  such  sections  as  are  necessary  .... 
P^orcej)s,  elevator,  or  other  instrument  is  used  for  pushing,  pulling,  or 
rotating  the  tooth  sections  into  pla(^e." 

He  advises  that  the  teeth  should  be  retained  by  ligatures  of  silk  or 
wire  or  a  splint  of  German  silver  or  platinum  bands  soldered  together, 
and  that  the  articulation  of  the  teeth  be  adjusted  by  grinding,  etc. 

Immediate  or  surgical  regulating  is  not  recommended  by  these  advo- 
cates for  all  cases,  but  only  for  those  in  which  all  circumstances  favor 
it,  such  as  lack  of  time  for  other  treatment,  desire  of  patient,  yielding 
alveolar  process,  abundance  of  room,  etc.  While  it  is  a  possible  opera- 
tion, it  will  never  become  a  frequent  one. 

Combined  Method,  Surgical  and  Mechanical. — Dr.  Talbot  advo- 
cates the  surgical  removal    of  a  portion  of    the  alveolar  process  in 

Fig.  833. 


Surgical  retraction  of  lower  cuspids  (Talbot). 

the  path  of  the  advancing  tooth  while  a  tooth  is  moved  by  usual 
means,  thus  avoiding  the  delay  caused  by  the  slow  process  of 
absorption.  This  is  especially  advantageous  in  case  of  very  dense 
tissue  and  in  cases  in  which  it  is  difficult  to  secure  sufficient 
anchorage.  By  thus  removing  the  chief  obstruction,  teeth  may  be 
moved  by  depending  on  an  anchorage  that  in  ordinary  cases  would  be 
entirely  inadequate.     He  says  :  ^ 

"  For  seventeen  years  I  have  adopted  surgical  treatment,  but  have 
not  made  public  my  methods,  since  incidental  conversation  with  some 
*  Dental  Cosmos,  1896,  vol.  xxxviii.  p.  909. 


IMMEDIATE  MOVEMENT  OF  TEETH. 


803 


of  the  best  men  from  time  to  time  revealed  that  they  had  not  taken 
kindly  to  it.  I  therefore  wished  to  give  it  sufficient  trial  before 
recommending  it  to  the  profession.  I  have  met  with  such  markedly 
uniform  success  that  I  do  not  hesitate  to  recommend  it  to  all  practi- 


FiG.  834. 


Surgical  retraction  of  incisors  and  cuspids  tTalbot). 

tioners  as  perfectly  safe  and  reliable  with  the  antiseptic  care  required 
in  surgical  operations.  This  method  consists  in  removing  entirely  the 
alveolar  process  in  the  line  of  travel  of  the  tooth  to  be  moved,  leaving 
a  small  amount  of  process  about  the  root  of  the  tooth,  holding  intact 

Fig.  835. 


"^**»Willlll.ail!l!ill!!i!l!lllllllill''l!l^ 
Surgical  correction  of  malposed  cuspid  (Talbot). 

the  peridental  membrane.  This  is  accomplished  with  coarse-cut  Reve- 
lation burs,  or  those  that  will  cut  in  all  directions.  They  can  thus  be 
used  as  drills  in  certain  conditions  to  be  mentioned  later  on. 

"  If  the  canines  require  to  be  carried  backward,  make  an  a]>pliance 
with  bands  about  the  first  and  second  molars,  with  cap  upon  the  canines 
and  a  bar  with  screw  and  nut  upon  the  end,  as  recommended  by  Dr. 


804 


ORTHODONTIA   AS  AN  OPERATIVE  PROCEDURE. 


Farrar.  Extract  the  first  bicuspid  and  adjust  the  appliance ;  use  a  sharp 
now  bur  dipped  in  five  per  cent,  carbolic  acid  or  one  per  cent,  corrosive 
sublimate  or  listerine.  Then,  resting  the  hand  against  the  canine,  cut 
out  the  palatal  and  buccal  V-shaped  plate,  making  a  concave  surfiice 
of  the  alveolar  process,  as  illustrated  in  Fig.  833. 

"If  the  upper  incisors  are  to  be  carried  back,  cut  semicircular 
spaces  just  posterior  to  the  teeth  to  be  moved  (Fig.  834).  To  carry  a 
canine  into  place  which  is  erupting  into  the  vault  of  the  mouth,  remove 
the  alveolar  process  in  the  direction  of  the  line  of  travel  (Fig.  835). 

"  In  moving  teeth  laterally  by  a  jack-screw,  it  will  be  found  that  not 
infrequently  one  tooth  moves  faster  than  the  other.  To  bring  both  to 
their  proper  position  cut  out  the  alveolar  process  on  the  side  of  the 
slowest-moving  tooth,  and  both  will  come  into  proper  position  (Fig.  836). 
To  rotate  a  tooth,  cut  a  circular  groove  as  deep  as  possible  around  the 
tooth,  leaving  enough  process  to  hold  the  peridental  membrane  intact 
(Fig.  837).     In  this  manner  teeth  may  be  moved  very  rapidly  and  witli- 


FiG.  837. 


Fig.  836. 


Spreading  cuspids  (Talbut). 


Rotation  (Talbot). 


out  much  pain.  This  should  always  be  done  by  means  of  screws.  By 
this  method  we  have  the  tooth  or  teeth  to  be  moved  completely  under 
control.  Any  of  the  teeth  in  the  mouth  may  be  used  for  the  fixed 
point  of  resistance,  thus  doing  away  with  all  unsightly  appliances  out- 
side the  mouth.  When  in  place,  they  should  be  anchored  in  the  usual 
manner.  Antiseptic  washes  should  be  used  from  time  to  time,  such  as 
one  per  cent,  corrosive  sublimate,  listerine,  or  five  per  cent,  carbolic  acid. 
"  In  operations  of  this  nature  the  peridental  membrane  and  also  the 
periosteum  are  apt  to  be  injured.  This  was  the  particular  question  in 
recommending  it  to  the  profession.  Although  I  have  had  a  few  cases 
of  infection,  I  am  quite  certain  now  that  such  injuries  are  not  of  any 
serious  consequence,  since  with  proper  precaution  no  bad  results  will 
follow." 


CHAPTER    XXV. 

tSe  development  of  esthetic  facial  contours. 

By  Calvin  S.  Case,  D.  D.  S.,  M.  D. 


I.  Influence  of  the  Teeth  on  the  Physiognomy. 

In  the  developmental  processes  of  animal  life  the  teeth  have  proba- 
bly been  more  influential  than  any  of  the  other  organs  in  shaping  the 
bones  of  the  head — especially  in  determining  the  physical  characteristics 
of  the  physiognomy.  The  physical  shape  and  structure  of  tlie  jaws 
conclusively  show  the  influence  that  the  teeth  have  exerted  in  diiferent 
species  in  response  to  Nature's  law  to  propagate  that  which  would  best 
subserve  them  in  the  performance  of  their  functions.  The  importance 
of  the  teeth,  therefore,  and  their  inherent  demand  upon  surrounding 
anatomical  structures  for  proper  means  of  development,  sustenance,  and 
use,  is  evidence  that  they  exert,  during  development,  a  more  or  less  im- 
mediate influence  in  determining  the  size  and  shape  of  the  maxillary 
bones,  and  thus  indirectly  are  extensively  influential  in  characterizing 
the  individual  shape  of  the  human  face. 

Often  the  position  of  the  anterior  teeth  and  alveolar  process  is  such 
as  to  impress  upon  the  contiguous  features,  even  in  repose,  certain  con- 
ditions which  vary  from  a  slight  imperfection  in  esthetic  contour  to  a 
most  distressing  facial  deformity.  Nor  are  these  dento-facial  imperfec- 
tions always  wholly  due  to  a  malposition  of  the  teeth,  so  much  as  to  a 
lack  of  normal  symmetry  in  the  size  or  shape  of  the  maxillary  bones 
upon  which  so  large  an  area  of  the  face  is  dependent  for  its  contour. 
These  conditions  may  have  arisen  from  the  direct  inheritance  of  a 
parental  deformity,  or  from  the  inharmonious  union  of  unaltered  types, 
as  the  teeth  of  one  parent  and  the  jaws  of  another.  It  is  equally  true 
that  the  union  of  harmonious  types  often  results  in  symmetrical  condi- 
tions which  neither  parent  possesses. 

Among  local  causes,  or  those  which  operate  after  birth  in  the  j^ro- 
duction  of  facial  imperfections,  may  be  mentioned  habits,  impaired 
dentition,  delayed  and  injudicious  extraction  of  the  deciduous  teeth  or 
first  permanent  molars,  and  mal-occlusion. 

The  influence  of  the  teeth  during  the  time  of  their  eruption  (produ- 

805 


806       THE  DEVELOPMENT  OF  ESTHETIC  FACIAL  CONTOURS. 


cing  on  the  one  luuid  the  excessive  pressure  of  large  teeth  and  concomi- 
tant alveolar  development,  and  on  the  other  a  lack  of  pressure  from  an 
irregularity  or  injudicious  extraction)  in  effecting  a  change  in  the  in- 
herent shape  or  size  of  the  maxillary  bones  beyond  that  which  the 
alveolar  process  is  forced  to  assume  to  accommodate  them,  has  been  a 
question  of  considerable  controversy.  It  is  reasonable  to  assume,  how- 
ever, that  natural  influences  exerting  a  slight  force  upon  the  immature 
maxillary  or  other  bones,  during  early  stages  of  their  growth,  would 


Fig.  838. 


Fig.  839. 


Fig.  840. 


have  somewhat  the  same  effect  that  is  known  to  be  possible  later  by 
artificial  force. 

The  following  case  will  serve  to  illustrate  this  principle  : 
Patient  aged  thirteen  years.     When  presented  the  upper  incisors 

were  fully  the  width  of  a  tooth  posterior 
to  a  normal  position,  and  so  badly  in- 
locked,  in  occlusion,  that  the  crowns  were 
nearly  hidden  behind  the  lower.  (See 
Fig.  838.)  With  the  exception  of  the 
upper  canines,  which  were  forced  slightly 
out  of  alignment,  all  the  other  teeth  in 
both  jaws  were  in  proper  position  and 
occlusion.  (See  Fig.  839.)  The  posterior 
position  of  the  inlocked  incisors  was  not 
due,  in  the  slightest  degree,  to  a  lingual 
inclination  of  their  crowns,  but  the  re- 
trusion  extended  to  the  roots  as  well 
and  seemed  to  involve  the  intermaxil- 
lary process,  producing  a  decided  depression  of  the  overlying  features. 
(See  Fig.  840.) 

The  probable  history  of  the  cause  of  this  condition  is  as  follows  : 
The  lower  incisors  erupted  much  earlier  than  the  upper,  and  there  being 


INFLUENCE  OF  THE  TEETH  ON  THE  PHYSIOGNOMY.        807 

a  short-bite  occlusion,  as  soon  as  the  upper  incisors  began  to  erupt  they 
became  inlocked  Avith  the  lower  incisors.  At  this  time  the  roots  and 
surrounding  processes  were  in  an  immature  condition.  As  the  crowns 
continued  to  erupt  they  slid  down  the  posterior  faces  of  the  lower  in- 
cisors, where  they  were  retained  during  the  continued  development  of 
the  roots  in  the  opposite  direction,  the  force  being  sufficient  to  prevent 
the  natural  growth  and  development  of  the  entire  intermaxillary  process, 
which  normally  would  have  carried  them  bodily  forward  to  an  harmo- 

FiG.  s-n. 


(Before.) 


(After.) 


nious  position.  As  the  other  teeth  came  into  place  the  lateral  portions 
of  the  jaw  were  allowed  to  normally  develop  in  harmony  with  the  natural 
growth  of  the  other  parts.  Thus  the  canines  and  bicuspids  were  found 
in  their  proper  relative  positions  as  regards  the  lower. 


Fm.  S42. 


Fig.  843. 


Force  was  applied  with  the  contouring  apparatus  described  in  section 
VI.  of  this  chapter.  In  less  than  six  months  the  incisors  were  carried 
bodily  forward  in  an  upright  position,  together  with  the  entire  surround- 
ing alveolar  ridge  and  intermaxillary  process  (see  Figs.  841  and  842), 


808       THE  DEVELOPMENT  OF  ESTHETIC  FACIAL   CONTOURS. 


Fig.  844. 


with  a  perfect  correction  of  a  vciy  unliappy  facial  (lefonnity.  (See 
Fig.  8  43.)  Fig.  844  is  from  a  photograph  taken  three  years  after  the 
completion  of  the  operation. 

In  dental  orthopedia  we  possess  the  great  advantage  over  general 

orthopedia  of  applying  force  directly 
to  the  bone  itself,  through  the  medium 
of  the  teeth,  without  the  intervention 
of  the  soft  and  sensitive  tissues. 

The  teeth  imbedded  in  the  alveolar 
process,  that  in  turn  is  firmly  united  to 
the  true  bone,  may  be  considered,  when 
in  the  grasp  of  a  regulating  machine, 
as  an  integral  part  of  it,  firmly  and  di- 
rectly attached  to  that  part  of  the  bone 
we  desire  to  move,  and  capable  of 
exerting  the  quality  and  direction  of 
force  the  machine  gives  to  them. 
This  force  being  applied  unitedly  to  a  number  of  teeth  standing  side 
by  side,  the  surrounding  and  contiguous  bone — w^hich  is  largely  a  can- 
cellated structure — is  carried  bodily  in  the  direction  of  the  force  ;  not 
by  the  fracture  of  its  substance  or  to  any  great  extent  by  a  metamor- 
phosis of  tissue,  but  by  the  bending,  condensation  and  elongation  of  its 
cellular  structure  ;  the  whole  adapting  itself  to  a  new  form,  in  which 
position  the  immediate  interstitial  tension  of  its  particles  is  soon  relieved 
and  brought  to  equilibrium  by  Nature — though  it  may  require  to  be 
held  in  that  position  for  many  months  before  there  is  an  entire  relief 
from  the  inherent  tendency  to  return  to  the  primary  position. 

In  contemplating  the  treatment  of  a  dental  irregularity  a  careful 
study  of  the  physiognomy  in  different  attitudes  of  expression  should  be 
made,  with  the  view  of  determining  the  relative  position  of  teeth  and 
facial  contours.  The  value  of  a  careful  preliminary  facial  examination 
and  comparison  cannot  be  overestimated,  for  it  is  often  the  only  guide 
to  correct  treatment. 

For  instance,  since  it  has  become  possible  to  expand  or  retract  the 
anterior  portion  of  the  upper  apical  arch  with  the  surrounding  bone  in 
which  the  moving  roots  are  imbedded,  we  are  no  longer  confined  to  the 
possibility,  and  frequent  questionable  propriety,  of  permanently  moving 
the  lower  jaw  forward  or  backward  to  correct  a  facial  deformity  which 
pertains  exclusively  to  the  upper  maxillae  and  middle  features  of  the 
face. 

n.  Principles  of  Facial  Orthopedia. 

The  portion  of  the  human  face  that  it  is  possible  to  change  with  a 
dental  regulating  apparatus  may  be  said  to  lie  between  two  diverging 


PRINCIPLES  OF  FACIAL   ORTHOPEDIA. 


809 


Fig.  84o. 


lines  which  arise  at  a  point  below  the  ridge  of  the  nose  and  curve  down- 
ward to  inclose  the  aloe  and  depressions  on  eitiier  side ;  tiience  laterally 
to  encircle  a  portion  of  the  cheek,  and  downward  to  inclose  the  entire 
chin.     (See  Fig.  845.) 

Within  this  ovoidal  area  are  the  main  features  of  expression. 
Within  this  space  the  slightest  change  of 
contour  will  often  produce  a  marked  eifect 
upon  the  entire  physiognomy  and  give  a 
diiferent  expression  to  the  countenance. 
It  is  here  that  an  inherited  or  an  acquired 
lack  of  symmetry  in  the  size,  shape,  or 
position  of  the  teeth  and  jaws  produces 
those  marked  changes  of  facial  contour 
which  characterize  different  physiogno- 
mies. This  area  may  be  termed  the 
"  changeable  area  "  in  contradistinction  to 
the  more  stable  features,  or  "  unchangeable 
area." 

For  convenience  of  ready  reference, 
the  features  in  that  portion  of  the  change- 
able area  which  are  bounded  laterally  by 
the  naso-labial  lines  may  be  divided  into  four  segments  as  follows : 

Segment  1. — The  end  of  the  nose  and  the  upper  portion  of  the  upper 
lip,  including  the  naso-labial  depressions. 


Fig.  846. 


Unchangeable  area  . 


Changeable  area  ■    - 


Segment  2. — The  lower  portion  of  the  upper  lip. 
Segment  3. — The  lower  lip. 
Segment  4- — The  chin. 


810       THE  DEVELOPMENT  OF  ESTHETIC  FACIAL   CONTOURS. 

In  the  preliminary  examination  of  the  physiognomy  from  a  purely 
esthetic  standpoint  with  a  view  of  correctin<^  a  dento-facial  deformity 
or  imperfection  by  applying  force  to  the  teeth,  there  are  certain  promi- 
nent features  to  be  especially  observed  and  their  relative  position  care- 
fullv  noted.  These  may  be  divided  into  two  classes  :  first,  those  which 
lie  in  the  unchangeable  area,  as  the  forehead,  bridge  of  the  nose,  and 
malar  prominences ;  second,  those  in  the  changeable  area. 

The  four  segments  in  the  latter  class  shown  in  Fig.  846  are  change- 
able in  their  relations  to  each  other,  and  also  in  their  individual  relation 
to  features  in  the  unchangeable  area.  For  instance,  it  is  possible  to  pro- 
trude or  retrude  the  upper  portion  of  the  upper  lip  with  the  depressions 
on  each  side  of  the  nose,  the  nasal  septum,  and  the  end  of  the  nose, 
without  changing  the  lower  portion  of  the  upper  lip  in  its  relation  to 
other  parts.  (See  Fig.  855.)  The  same  is  true  of  the  other  segments 
— in  fact,  a  retrusion  of  the  second  segment  and  a  protrusion  of 
the  first  may  be  accomplished  at  the  same  time.  (See  Figs.  853 
and  854.) 

If  the  lower  jaw  be  mechanically  protruded  or  retruded  bodily,  the 
lower  lip  will  of  necessity  be  carried  forward  or  backward  with  the 
chin,  unless  a  special  operation  is  performed  on  the  lower  teeth  to  pre- 
vent it  from  changing  its  relations  to  the  upper  lip. 

Those  portions  of  the  changeable  area  which  lie  over  the  bicuspids 
and  first  molars — shown  in  Figs.  845  and  846 — and  separated  from  the 
lips  by  the  naso-labial  lines,  may  be  considered  as  separate  segments,  as 
the  causes  which  influence  a  change  in  the  contour  of  the  cheeks  diifer  so 
decidedly  from  those  which  change  the  more  anterior  areas.  The  lateral 
expansion  or  contraction  of  the  dental  arches  will  often  change  the  con- 
tour of  the  cheeks  with  no  effect  upon  the  labial  area,  if  the  anterior 
teeth  remain  unchanged  in  position.  Again,  a  decided  retrusion  of  the 
anterior  teeth  and  process  with  no  lateral  expansion  of  the  arch  will 
invariably  result  in  giving  to  the  cheeks  a  fuller  contour,  by  relieving 
the  tension  of  muscular  tissues.  The  same  result  will  often  be  obtained 
in  closing  the  characteristic  open  bite  of  a  mouth-breather  by  grinding 
the  posterior  teeth,  and   also  by  retracting  a  prognathous  lower  jaw. 

In  a  study  of  profiles  we  frequently  observe  a  lack  of  perfect  har- 
mony in  the  position  of  the  chin.  The  lower  jaw  is  apparently 
protruded,  or  retruded,  so  as  to  mar  the  esthetic  perfection  of  the 
physiognomy,  and  yet  were  these  same  faces  examined  by  a  trained 
observer  he  would  find  in  a  large  proportion  the  lower  jaw  in  perfect 
harmony  with  the  unchangeable  area,  and  that  the  appearance  of  its 
malposition  was  an  effect  due  wholly  to  a  protrusion  or  retrusion  of  the 
upper  jaw  and  teeth.  In  other  words,  it  is  a  common  error  to  imagine 
the  chin  imperfectly  posed  because  it  is  not  in  harmonious  relations  to 


UPPER  DENTAL  AND  MAXILLARY  PROTRUSIONS.  811 

the  other  features  of  the  changeable  area,  instead  of  comparing  it, 
as  we  should  do,  to  the  more  stable  or  unchangeable  features  of  the 
physiognomy. 

In  examining  the  physiognomy  of  a  patient,  the  head  should  be  in 
an  upright  position,  on  a  line  with  that  of  the  observer,  and  the  face 
studied  from  dilferent  angles  while  in  repose  and  in  action. 

While  looking  at  the  profile  in  repose  the  most  important  thing  to 
determine  is  the  relative  position  of  the  chin  with  the  forehead,  malar 
prominences,  and  bridge  of  the  nose.  If  its  position  is  harmonious 
with  the  unchangeable  area  and  the  lower  lip  is  well  posed,  it  indicates 
that  the  operation  of  facial  contouring  should  be  performed — if  any- 
where— upon  the  upper  jaw  and  teeth.  For  if  the  first  and  second  seg- 
ments are  abnormally  protruded  it  will  cause  a  chin  to  appear  retruded 
that  is  perfectly  harmonious  in  its  relations  to  the  principal  features  of  the 
face.  (See  Fig.  847.)  Again,  a  retruded  or  contruded  upper  arch  with 
a  depression  of  those  features  wliich  are  supported  by  the  upper  maxillae 
will  cause  a  perfectly  posed  lower  jaw  and  chin  to  appear  protruded  or 
prognathous  ;  as  instanced  by  the  cases  illustrated  in  sections  I.  and  IV. 
in  which  the  facial  effect,  before  treatment,  was  that  of  protruded  lower 
jaw,  but  which  were  perfectly  corrected  by  an  anterior  movement  of 
the  upper  incisors  and  intermaxillary  processes. 

ni.  Upper  Dental  and  Maxillary  Protrusions. 

Figs.  847  and  848  w411  serve  to  illustrate  the  class  of  facial  de- 
formities known  as  abnormal  upper  protrusions,  and  the  advantage  of 
retruding  the  upper  anterior  teeth  and  surrounding  process. 

Fk;.  S47. 


In  Fig.  847  M'ide  interdental  spaces  between  the  upper  teeth  per- 
mitted the  reduction  without  extracting.  In  Fig.  848  the  upper  first 
bicuspids  were  extracted. 


812       THE  DEVELOPMENT  OF  ESTHETIC  FACIAL   CONTOURS. 

If  the  operation  of  "jnm])ing  tlie  bite"  were  performed  in  these 
eases,  there  wouhl  no  donbt  be  an  iniproNcnient  of  tlie  ori<jinal  aj^pear- 
ance  of  the  physiognomy,  by  the  l)rin<ifin<;  of  tlie  chin  and  lower  lij) 
into  more  perfect  harmony  with  the  upj)er  ;  but  this  would  not  be  cor- 
rect treatment,  because,  as   will   be  observed,   the  chin    is   in    not   far 

Fui.  S48. 


from  perfect  position  when  compared  with  other  features  of  the  un- 
changeable area. 

The  principles   involved   in   the  correction   of  this  class  of  facial 
deformities  may  be  diagrammatically  illustrated  as  follows  : 

Fig.  849.  Fig.  850. 


Fig.  849  is  a  profile  view  of  a  typical  case  of  abnormally  protruded 
upper  jaw.     It  will  be  observed  that  the  chin  appears  retracted. 

Fig.  850  shows  the  improved  effect  that  would  be  produced  by 


UPPER  DENTAL  AND  MAXILLARY  PROTRUSIONS. 


813 


"jumping  the  bite"  in  bringing  segments  3  and  4  into  more  perfect 
harmony  with  segments  1  and  2 ;  yet  not  to  be  compared  with  that  per- 
fection of  symmetrical  contour  shown  by  Fig.  851,  where  the  chin  and 
lower  lip  are  permitted  to  remain  in  their  original  harmonious  position 
while  the  end  of  the  nose  and  upper  lip  are  retruded  into  harmony  with 
the  whole. 

The  three  faces  have  been  made  exactly  alike  with  the  exception — 
as  shown  by  the  cross  lines — of  certain  mechanical  movements  of  the 
profile  outlines  in  the  changeable  area.  In  Fig.  850  the  outlines  of 
segments  3  and  4  are  forced  farther  forward,  and  in  Fig.  851  segments 


Fig.  851. 


Fig.  852. 


]  and  2  are  carried  back  as  they  w'ould  be  by  a  retruding  apparatus 
attached  to  the  teeth. 

In  comparing  Figs.  849  and  851  the  difference  in  esthetic  effect  is 
quite  striking,  and  it  is  one  also  which  would  seem  to  be  hardly  possible 
Avith  so  little  change  in  the  outlines  of  a  comparatively  small  area.  By 
cutting  a  piece  of  black  paper  to  the  exact  outlines  of  Fig.  851  and 
placing  it  upon  Fig.  849  the  real  and  only  ditlerence  in  the  two  figures 
can  be  plainly  seen — as  in  Fig.  852. 

AVhen  such  a  change  is  produced  in  the  features  of  a  human  face  the 
difference  is  greatly  enhanced  because  of  the  harmonious  perfection  of 
other  contours  not  shoMU  by  the  figures. 

It  is  a  noteworthy  fact  that  a  very  little  change  in  the  peripheral 
shape  or  position  of  certain  bones  of  the  face  on  which  the  features  are 
dependent  for  their  character  and  form — a  change  so  trifling  that  it  could 


814       THE  DEVELOPMENT  OF  ESTHETIC  FACIAL   CONTOURS. 

hardlv  be  measured — resulting  in  a  slight  filling  out  or  depression  of 
certain  contours,  will  often  beautify  to  a  remarkable  degree  the  ap- 
pearance of  a  face  that  would  otherwise  be  quite  plain  and  unattractive. 

This  is  true  of  all  the  more  common  cases  of  upper  protrusion  and 
retrusion  which  show  an  abnormal  prominence  or  depression  along  the 
upper  as  well  as  the  lower  portion  of  the  upper  lip,  and  especially  of 
those  which  seem  to  involve  the  entire  intermaxillary  process,  influ- 
encing the  anteroposterior  position  of  the  wings  and  end  of  the  nose. 

In  cases  of  protrusion,  by  applying  a  retracting  force  especially 
directed  to  the  roots  and  crowns  of  the  anterior  teeth,  the  surrounding 
alveolar  process  and  anterior  portion  of  the  maxillae  will  be  forced 
back,  allowing  the  upper  lip  to  fall  into  a  more  graceful  and  easy  pose, 
leaving  the  nostrils  less  broad  and  open,  the  upward  curve  of  the  nose 
straightened,  and  its  pug-like  appearance  removed. 

When  an  upper  protrusion  is  due  alone  to  a  labial  inclination  of 
large  crowded  teeth,  with  no  marked  protrusion  over  the  apical  zone,  or 
in  segment  1,  the  extraction  of  the  first  or  second  bicuspids  is  indicated, 
and  the  application  of  force  to  the  crowns  at  such  points  and  in  such 
direction  as  will  best  overcome  the  malposition. 

Many  instances  have  arisen,  in  the  practice  of  dentists  who  were 
opposed  to  the  extraction  of  teeth,  where  the  above  condition  has 
actually  been  produced  in  the  operation  of  crowding  irregular  teeth  into 
alignment  that  were  too  large  for  an  already  perfectly  harmonious 
maxillary  arch.     (See  Figs.   875    to   878   inclusive,  in  section  V.) 

There  are  innumerable  instances  where  a  labial  inclination  of  both 
the  upper  and  lower  anterior  teeth  produces  a  pronounced  protrusion  of 
the  lips  with  a  very  unpleasant  expression  in  their  management,  espe- 
cially if  in  occlusion  the  lower  anterior  teeth  are  even  with,  or  in  front 
of,  the  uppers.  The  fact  that  the  most  natural  occluding  position  of 
the  lower  front  teeth  is  somewhat  posterior  to  the  upper  teeth  permits 
the  graceful  curve  of  the  lower  lip  which  is  so  necessary  to  the  esthetic 
perfection  of  the  chin. 

In  order  to  correct  a  pronounced  facial  deformity  of  this  character 
produced  by  large  teeth  crowded  into  arches  that  are  too  small  for  them, 
but  otherwise  harmonious  in  size,  it  will  often  be  necessary  to  extract  a 
bicuspid  from  each  side  from  both  the  upper  and  lower  jaws.  Some- 
times the  extraction  from  the  lower  of  a  central  incisor  will  be  suf- 
ficient. 

Instances  frequently  arise  where  the  position  and  labial  inclination 
of  the  upper  anterior  teeth  produce  a  relative  protrusion  of  the  incisal 
zone  and  a  contrusion  of  the  apical,  with  a  protrusion  of  the  lower 
portion  of  the  upper  lip  and  a  slight  depression  of  the  upper  portion, 
deepening  the  naso-labial  depressions.     If  the  depression  of  segment  1 


UPPER  DENTAL  AND  MAXILLARY  PROTRUSIONS.  815 

be  not  too  pronounced,  it  may  be  restored  by  a  slight  forward  movement 
of  the  anterior  apical  zone,  accomplished  in  the  retrusion  of  the  incisal 
zone — by  force  applied  at  the  incisal  ends  of  the  teeth  alone,  with  the 
yiew  of  producing,  as  far  as  possible,  a  fulcrum  force  at  the  lingual 
margins  of  the  alveoli. 

If  the    malformation   is   produced    bv   an    inharmonious   union   of 

Fig.  853. 


maxilUe  and  teeth,  as  in  the  former  case,  the  extraction  of  an  upper 
bicuspid  from  each  side  will  be  indicated.  Figs.  853  and  854  were  made 
from  the  models  of  a  case  of  this  character,  before  and  after  treatment. 
The  upper  first  bicuspids  had  been  extracted  some  time  before  the 
patient  presented  for  treatment. 

In  contradistinction   to   this  class   of  deformities,  there  is  another 

Fig.  854. 


quite  as  common — though  not  so  frequently  recognized  as  an  abnor- 
mality— in  which  all  the  conditions  are  reversed,  in  that  the  teeth  have 
a  lingual  inclination  with  protrusion  of  the  apical  zone  and  maxilla?. 

The  teeth  of  these  cases  are  commonly  regular  in  alignment,  and 
owing  to  their  lingual  inclination  the  occlusal  zone  may  be  in  proper 
relative  position.     (See  Fig.  855.) 


816       THE  DEVELOPMENT  OF  ESTHETIC  FACIAL  CONTOURS. 

The  facial  imperfection  which  consists  principally  in  a  prominence 
or  bulging  along  the  higher  portions  of  the  upper  lip  and  in  the  region 
of  the  na.sal  alie  is  often  quite  pronounced.  When  this  is  caused  partly 
by  the  canine  roots  the  difficulties  are  much  increased  in  the  case  of 
patients  older  than  thirteen.  The  fact  that  the  roots  of  the  canines  are 
surrounded  by  the  most  dense  i)ortion  of  the  alveolar  process,  and  their 
movement  bodily  in  a  posterior  direction  requiring  the  resorption  of  a 
large  portion  of  bone,  makes  this  operation  one  of  the  most  difficult  in 
dental  orthopedia. 

Fig.  855  is  from  the  models  of  a  patient  over  twenty  years  of  age, 

Fk;.  855. 


and  will  serve  to  illustrate  a  case  before  and  after  treatment  of  abnormal 
protrusion  of  the  roots  of  the  upper  anterior  teeth,  alveolar  process  and 
maxillae — the  axis  of  the  incisors  being  inclined  lingually. 

It  will  be  observed  that  the  canines  have  been  moved  bodily  in  a 
posterior  direction  notwithstanding  the  advanced  age  of  the  patient. 

If  regulating  appliances  are  properly  constructed  that  will  permit 
the  production  of  an  independent  static  fulcrum  at  the  occlusal  ends  of 
the  teeth,  so  that  the  entire  power  of  the  machine  may  be  directed  and 
maintained  upon  the  roots  (see  Figs.  896  and  897,  in  section  VI.)  per- 
fect contrusion  of  the  prominence  will  slowly  but  surely  result. 


UPPER  DENTAL  AND  MAXILLARY  RETRUSIONS.  817 

If  the  teeth  are  crowded,  overlapping,  or  turned  on  their  axes,  a 
correction  of  alignment  may  require  the  extraction  of  a  bicuspid  on 
each  side  in  order  to  regulate  them  without  an  abnormal  protrusion  of 
their  crowns.  This  is  especially  indicated  when  much  retrusion  of  the 
canine  roots  is  desired. 

IV.  Upper  Dental,  and  Maxillary  Retrusions. 

Facial  imperfections  which  are  due  to  insufficient  fulness  of  contour 
in  the  central  features  of  the  physiognomy  are  quite  common,  and  vary 
in  degree  from  conditions  that  are  hardly  noticeable  to  those  which  may 
well  be  classed  among  the  most  unhappy  of  facial  deformities. 

There  are  two  distinct  classes  of  this  type  of  facial  irregularity — 
one  being  due  to  a  lack  of  development  of  the  intermaxillary  portion 
of  an  otherwise  harmonious  upper  jaw ;  the  other  to  the  fact  that  the 
entire  upper  jaw  itself  is  too  small  and  too  posteriorly  placed,  in  its 
relations  to  other  parts. 

The  teeth  and  alveolar  process  of  the  retracted  parts  are  prevented 
from  assuming  harmonious  relations,  and  consequently  the  overlying 
features  are  more  or  less  depressed  in  proportion  to  the  contruded  or 
retruded  frame  upon  which  they  depend  for  their  contour. 

The  primary  cause  of  these  conditions  may  be  often  very  obscure 
and  admit  of  nothing  more  tangible  than  conjecture,  and,  not  unlike 
many  of  the  causes  of  irregular  teeth,  be  really  immaterial  to  the  work 
of  correction. 

It  may  have  been  caused  by  the  exertion  of  local  physical  forces 
during  the  early  years  of  immaturity  (as,  for  instance,  the  mal-eruption 
and  occlusion  of  the  teeth) ;  or  a  local  disturbance  and  interruption  of 
nutrition  from  prenatal  or  postnatal  causes  ;  and  lastly,  but  by  no  means 
rarely,  by  inherent  physical  tendency. 

Class  1  :  Retruded  Uppe)-  Incisors  and  Iniermaxillary  Process. — 
In  the  more  pronounced  deformities  of  this  class  the  physiognomy 
will  often  appear  flattened,  with  prominent  cheek  bones  and  protruding 
chin  and  lower  lip ;  the  upper  incisors  occlude  evenly  with  or  posterior 
to  the  lower  incisors,  and  at  times  are  extensively  inlocked  in  this  posi- 
tion, as  instanced  by  the  case  fully  described  and  illustrated  in  section  I. 

The  upper  incisors,  which  alone  have  their  origin  in  the  intermax- 
illary process,  are  in  their  entirety  posterior  to  a  normal  relative  posi- 
tion. The  labial  inclination  of  the  crowns,  together  with  the  deepened 
incisive  fossae,  will  show  at  once  the  contruded  position  of  the  roots  and 
their  maxillary  surroundings. 

The  upper  lip  resting  upon  the  retruded  teeth  and  the  overlying 
process  is  proportionately  depressed.  Nor  does  the  facial  defect  end 
here.     The  entire  lower  portion  of  the  nose,  supported  as  it  is  by  the 

52 


818      THE  DEVELOPMENT  OF  ESTHETIC  FACIAL  CONTOURS. 


Fig.  S5G. 


nasal  cartilages  which  spring  from  the  anterior  nasal  spine  and  lateral 
borders  of  tlie  nasal  orifice,  is  often  decidedly  affected  in  shape  by  the 
retracting  influence  of  its  supports. 

"When  there  is  a  decided  retrusion  of  the  entire  upper  lip  and  lower 
portion  of  the  nose,  with  ahe  resting  in  deep  depressions  caused  by  the 

unusual  j^rominence  of  the  naso-labial 
folds,  the  effect  is  that  of  an  abnormal 
protrusion  of  surrounding  parts,  pro- 
( hieing  at  times  a  startling  expression 
of  maturity  that  is  only  common  to 
persons  of  advanced  age.  This  expres- 
sion can  be  seen  in  Fig.  856,  which  is 
that  of  a  girl  only  twelve  years  of  age, 
and  will  serve  as  a  type  of  cases  com- 
monly met  with  in  practice. 

Class  2  :  Retruded  and  Contracted 
Dental  and  Maxillary  Arch. — In  this 
class  of  deformities  the  physiognomy, 
in  the  more  pronounced  cases,  has  much  the  same  characteristics  as 
those  described  above,  but  presenting  a  more  general  retraction  of 
the  central  features,  with  less  pronounced  naso-labial  folds.  The  nose 
is  often  thin  and  the  nostrils  pinched  ;  and  though  the  end  of  the  nose 
may  be  depressed,  the  distance  from  the  tip  to  the  more  depressed  lip 
is  often  lengthened.     If  the   patient  is  a  "mouth-breather"  with  the 


Fig.  857. 


Fig.  858. 


typical  "  open  bite,"  the  deformity  and  the  difficulties  attending  its 
reduction  will  be  greatly  increased. 

Fig.  857  is  from  a  profile  model  of  a  face  of  this  class.  Fig.  858 
is  from  the  same  model  photographed  at  a  slightly  different  angle  to 
show  the  angularity  of  tlie  features. 

Fig.  859  is  a  view  of  the  teeth  in  natural  occlusion.    The  first  lower 


UPPER  DENTAL  AND  3T AXILLARY  RETRVSIONS. 


819 


Fig.  859. 


bicuspids  have  been  removed  preliminary  to  retruding  the  anterior  teeth 
to  reduce  the  abnormal  protrusion  of  the 
loAver  lip  and  esthetically  deepen  the 
curve  between  the  border  of  the  lip 
and  the  chin.  The  figure  has  the  ap- 
pearance of  a  perfect  occlusion  of  all 
the  molars,  whereas,  on  account  of  the 
very'  great  narrowness  of  the  upper  jaw, 
the  buccal  cusps  of  the  second  molars 
only,  occluded  with  the  lingual  cusps 
of  the  lowers. 

Fig.  860  shows  palatal  views  of  the 
upper  arch  before  and  after  treatment. 

Fig.  861  is  a  view  of  teeth  in  natural 
occlusion  after  treatment.  The  entire  upper  dental  arch,  especially  at 
the  apical  zone,  was  considerably  enlarged.  The  "  open  bite  "  was  par- 
tially closed  by  grinding  the  molars  and  partly  by  extruding  the  teeth 
anterior  to  the  molars  with  small  rubber  bands  extending  from  the 
upper  to  the  lower  teeth.  Fig.  862  is  from  a  model  of  the  face  after 
treatment. 

As  mentioned  in  section  II.,  a  depression  of  the  central  features 
such  as  described  is  often  mistaken  for  a  prognathous  jaw,  and  treated 
accordiuijlv. 

Fig.  860. 


A  slight  retraction  of  the  lower  jaw  will  in  nearly  every  case  of  this 
character  produce  an  improvement  in  the  facial  aspect,  because  the  chin 
and  lower  lip  are  brought  into  more  perfect  harmony  with  the  depressed 
central  features.  Such  a  eliange,  however,  when  it  is  not  demanded, 
can  never  cause  the  beautifying  eifect  produced  by  forcing  the  depressed 
facial  features — in  segments  1  and  2 — forward,  thus  bringing  into  per- 
fect harmony  the  entire  jihysiognomy. 

This  can  be  verified  with  any  profile  view  of  a  typical  case — as  Fig. 


820      THE  DEVELOPMENT  OF  ESTHETIC  FACIAL   CONTOURS. 

863.  Fig.  864  is  the  same  face,  except  that  the  chin  and  h)\ver  lip  have 
been  retruded,  producing  a  certain  improvement,  but  not  to  be  com- 
pared with  Fig.  865,  where  the  chin  and  lower  lip  retain  the  same 
relative  position  to  the  unchangeable  area  as  in  Fig.  863,  while  segments 

Fig.  8(;1.  Fk;.  8G2. 


1  and  2  have  been  carried  forward,  with  a  result  which  proves  (not 
alone  in  theory,  but  in  practice)  this  to  be  the  only  true  course  to  bring 
about  an  harmonious  and  esthetic  adjustment  of  all  the  features  of  the 

Fig.  863.  Fig.  864. 


physiognomy.     Fig.  866   shows  the  actual  difference,   which  may  be 
verified  upon  trial,  between  Figs.  863  and  865. 

Fig.  867  will  serve  to  illustrate  the  common  result  in  practical  oper- 
ations of  this  character. 


UPPER  DENTAL  AND  MAXILLARY  RETRUSIONS.  821 

The  contouring  apparatus  (Fig.  895)  that  is  used  to  accomplish  these 
Fig.  865.  Fig.  866. 


results  is  fully  described  in  section  VI.  of  this  chapter.     With  it  the 

Fig.  867. 


apical  zone  of  the  anterior  teeth  may  be  enlarged  and  advanced  to  any 


822       THE  DEVELOPMENT  OF  ESTHETIC  FACIAL  CONTOURS. 

desired  degree  ;   while  the  movement  and  inclination  of  the  crowns  are 
under  the  perfect  control  of  the  operator. 

In  this  operation  it  will  be  found  in  a  majority  of  cases,  and  espe- 
cially with  those  which  are  begun  as  early  as  thirteen  or  fourteen  years 
of  age,  that  the  entire  intermaxillary  portion  of  the  upper  jaw  may  be 
carried  bodily  forward  with  the  roots  of  the  incisors. 

The  depressed  features  of  the  physiognomy — in  segments  1  and  2 
— that  are  dependent  for  their  contour  upon  that  portion  of  the  max- 
illae are  thus  brought  into  perfect  harmony  with  other  features  of  the 
face. 

It  is  not  here  implied  that  there  are  not  many  cases  of  real  prog- 
nathous jaw  where  its  retraction,  if  possible,  would  produce  a  most 
desirable  result ;  nor  that  such  an  operation  is  impossible  if  recognized 
and  treated  sufficiently  early  with  properly  adjusted  apparatus  per- 
sistently worn.  The  body  of  the  lower  jaw  can  certainly  be  forced  back 
to  a  more  posterior  position  in  its  relations  to  the  upper,  partly  by  bend- 
ing the  rami  and  necks  of  the  condyles,  and  partly  by  absorption  of  the 
posterior  wall  of  the  glenoid  fossse. 

The  many  failures  that  have  attended  these  operations  have  been 
largely  due  to  the  advanced  age  of  the  patients  and  much  to  the  fact 
that  the  apparatus  is  dependent  upon  the  will  or  caprice  of  the  patient 
for  its  persistent  application. 

On  account  of  the  early  maturity  and  ossification  of  the  lower 
maxilla,  these  operations  should  be  undertaken  as  early  as  from  five  to 
ten  years  of  age. 

The  caps  fitted  to  the  head  and  chin  should  be  made  to  exert  a  uni- 
form pressure  over  the  surfaces  upon  which  they  rest,  admit  of  free 
ventilation,  and  the  whole  apparatus  when  in  place  should  have  no 
projecting  parts  which  will  interfere  with  the  comfort  of  the  patient  at 
night. 

Fine  wire  gauze  answers  admirably  for  the  body  of  caps.  It  can  be 
cut  and  readily  shaped  to  any  contour.  First  cut  a  narrow  pattern  of 
thick  paper  to  accurately  fit  the  zone  indicated  by  the  desired  border  of 
the  skull-cap.  Duplicate  this  in  thin  tin  ;  solder  the  free  ends  together 
and  fit  to  the  head  to  see  that  it  takes  the  proper  position  and  desired 
flare.  Cut  the  pieces  of  gauze  a  little  in  excess  of  the  required  size 
and  force  it  into  the  rim,  where  it  should  be  tacked  at  one  point  only, 
with  soft  solder.  The  adjustment  is  finally  perfected  by  again  fitting  it 
to  the  head  and  a  line  drawn  along  the  borders  where  it  is  to  be  com- 
pletely soldered.  In  constructing  the  chinpiece,  first  make  a  frame  of 
German-silver  wire,  which  is  then  soldered  to  gauze  as  shown  in  Fig. 
868 — the  whole  to  be  shaped  to  produce  an  even  pressure  upon  the 
chin. 


PHYSIOGNOMY  AND   THE  SAVING   OF  TEETH. 


823 


Fig.  8G8. 


The  projecting  ends  of  the  wire  are  bent  so  as  to  lie  close  to  the  face, 
and  with  sufficient  extension  to  prevent 
the  rubber  bands  pressing  into  the 
cheeks.  The  ends  are  doubled  toward 
each  other  at  the  proper  angle  to  re- 
ceive the  bands. 

Small  wire  triangles  serve  to  attach 
the  rubber  bands  to  the  skull-cap,  by 
means  of  flat  buttons  sewed  to  the 
gauze.  Finally,  cover  the  rim  of  the 
cap  with  padded  silk  ribbon  and  line 
the  chinpiece  with  some  loosely  woven 
material,  binding  the  edges  with  silk. 

The  skull-cap  is  admirably  adapted 
also  for  applying  a  retruding  force  to  the  upper  anterior  teeth,  by 
means  of  a  bar  which  engages  with  an  encircling  wire  attached  to 
molar  anchorages. 


V.  The  Relations  of  the  Physiognomy  to  the  Saving-  and 
Extraction  of  Teeth. 

In  its  widest  scope  this  subject  includes  the  propriety  of  saving,  and 
on  the  other  hand,  the  propriety  of  extracting  certain  teeth  of  the 
deciduous  as  well  as  the  permanent  dental  arches  which  in  any  way 
influence  the  prevention,  the  production,  or  the  correction  of  dento-facial 


Fig.  869. 


Fig.  870. 


irregularities.  Two  phases  of  this  subject  will  be  here  presented.  The 
first  will  be  in  regard  to  the  saving  or  the  extraction  of  the  upper  bicus- 
pids for  patients  older  than  fourteen,  to  correct  a  dental  irregularity ; 
the  second  will  deal  with  the  early  extraction  of  the  bicuspids  to  pre- 
vent an  abnormal  upper  protrusion. 

In  the  common  form  of  dental  irregularity  shown  by  Fig.  869,  espe- 
cially if  only  the  model  of  the  upper  jaw  were  the  subject  of  study,  it 


824       THE  DEVELOPMENT  OF  ESTHETIC  FACIAL  CONTOURS. 


would  in  all  probability  be  decided  to  extract  the  first  bicuspids  as  the 
best  course  to  pursue  as  a  first  step  toward  securing  a  perfect  alignment 
of  the  dental  arch  ;  and  the  proceeding  would  probably  be  correct  as  far 
as  the  upper  teeth  alone  were  concerned.  And  again,  if  both  upper  and 
lower  models  were  studied  in  occlusion  and  the  irregularity  of  the  lower 
arch  was — as  is  usually  the  case — in  correspondence  with  that  of  the 
upper,  as  shown  in  Fig.  870,  the  extraction  of  the  lower  first  bicuspids 
would  doubtless,  and  correctly,  be  decided  upon.  This  plan  of  correc- 
tion might  even  be  decided  upon  after  a  superficial  study  of  the  face  of 
the  patient,  which  we  may  suppose  to  be  similar  to  that  shown  in  Fig. 
871.     Certainly  the  extraction  of  the  lower  first  bicuspids,  which  have 

Fig.  872. 


Fk; 

871. 

■ 

P 

-^^H 

m^^^ 

'    ^^m 

^H 

k 

h 

J 

just  begun  to  erupt,  and  the  retraction  of  the  anterior  teeth  would 
reduce  the  apparent  protrusion  of  the  lower  lip  and  bring  it  into  more 
perfect  harmony  with  the  depressed  upper  lip. 

Yet  when  this  face  is  carefully  studied  from  the  higher  standpoint 
of  esthetic  development  it  becomes  evident  that  the  chin  and  lower  lip 
are  not  protruded,  in  their  relations  to  the  malar  prominences,  the  bridge 
of  the  nose,  and  the  forehead,  but  that  the  central  features  of  the  physi- 
ognomy are  depressed  even  to  a  decided  retraction  of  the  lower  portion 
of  the  nose  ;  and  that  which  is  really  demanded  in  this  case  is  the  ad- 
vancement or  forward  movement  of  the  entire  intermaxillary  portion  of 
the  jaw  and  incisor  teeth ;  and  further,  every  tooth  in  that  dental  arch 
is  necessary  for  the  ultimate  retention  of  the  several  parts  in  their 
corrected  position. 

In  the  correction  of  malformations  which  demand  the  protrusion  of 
the  incisors  bodily  with  the  roots  and  intermaxillary  process,  the  posi- 
tion of  the  canines,  as  in  this  case,  will  frequently  prevent  the  proper 
attachment  and  application  of  apparatus  for  producing  the  desired 
effect ;  so  that  it  often  becomes  necessary  to  first  enlarge  the  dental  arch 
and  force  the  crowns  into  partial  alignment  by  ordinary  means,  pre- 


PHYSIOGNOMY  AND  THE  SAVING   OF  TEETH. 


825 


paratory  to  placing  the  incisors  in  the  grasp  of  contouring  forces.  Fig. 
872  shows  tiie  position  of  the  teeth  in  this  case  in  the  intermediate 
stage,  the  anterior  teeth  crowded  into  imperfect  alignment,  and  with 
no  special  facial  improvement.  (It  may  be  added  that  at  this  stage 
in  the  operation,  cases  of  this  kind  have  been  considered  finished, 
until  it  was  found  possible  to  enlarge  the  apical  arch.) 


Fig.  873. 


Fig.  874. 


Fig.  873  shows  correctly  the  final  result,  which  was  accomplished 
with  the  contouring  apparatus  described  in  section  VI.  It  will  be 
seen  that  the  incisors  are  in  an  upright  position  and  there  is  now 
ample  room  for  all  the  teeth,  while  the  remarkable  improvement  to  the 
physiognomy  is  poorly  shown  by  the  fiice  model  Fig.  874. 

Another  case,  that  of  the  upper  arch.  Fig.  875,  if  examined  alone 

Fig.  87G. 


and  compared  M-ith  the  upper  of  the  former  case,  or  Fig.  860,  will  be 
found  very  similar.  The  same  crowded  condition  of  the  teeth,  the  same 
lack  of  sufficient  room  for  the  proper  eruption  of  the  canines ;  and  yet 
this  is  from  the  model  of  a  case  that  absolutely  demanded  the  extraction 
of  the  bicuspids.  At  fourteen  years  of  age  the  irregularity  presented 
the  appearance  shown  in  the  illustration  Fig.  876,  showing  the  models 


826       THE  DEVELOPMENT  OF  ESTHETIC  FACIAL   CONTOURS. 


of  the  case  in  occlusion.  The  patient  was  placed  in  charge  of  a  dentist 
Avho  attempted  the  correction  of  the  irregularity  without  removal  of  the 
first  bicus})ids  :  Fig.  877  shows  the  result  two  years  afterward. 

It  will  be  seen  that  the  incisors  were  forced  forward  to  a  decided 
labial  inclination,  for  the  purpose  of  crowding  the  canines  into  align- 
ment ;  and  all  the  anterior  teeth  are  turned  on  their  axes  so  as  to 
occupy  the  least  possible  space.  Fig.  878  is  from  the  model  of  the  face 
of  the  patient  at  that  time. 

That  a  mistake  was  made  in  the  plan  of  treatment  pursued  is  evi- 
denced by  the  following  considerations  :  First,  the  protrusion  of  the 
crowns  of  the  upper  anterior  teeth  produces  an  unhappy  expression 
of  the  mouth  that  is  equivalent  to  a  deformity,  and  one  that  could  not 
be  remedied  in  this  particular  until  certain  members  of  the  dental  arch 
were  removed.  Second,  if  it  were  a  case  in  which  the  maxillary  arch 
Avas  too  small,  with  a  depression  of  the  overlying  features  of  the  face, 


Fig.  877. 


Fig.  87S. 


the  decided  labial  inclination  of  the  teeth  could  be  overcome  by  an 
enlargement  of  the  apical  zone,  which  would  have  permitted  a  slight 
retrusion  of  the  occlusal  zone  with  a  partial,  if  not  complete,  regulation 
of  the  dental  and  facial  deformity.  But  this  was  not  the  condition, 
and  therefore  could  not  be  considered.  The  third  and  most  effective 
argument  is  one  which  should  never  be  overlooked  in  all  cases  where 
the  crowns  flare  outward.  The  conical  shape  of  the  teeth  permits  them 
to  stand  in  perfect  alignment  though  with  a  decided  labial  inclination, 
but  in  this  position  the  interproximal  spaces  so  necessary  to  the  preser- 
vation of  the  teeth  are  so  completely  closed  as  to  cut  off  the  union  of 
interproximal  gum  tissue,  which  must  ultimately  result  in  the  resorp- 
tion of  the  gum  and  alveolar  process  and  all  the  dire  consequences  that 
follow. 

Had  the  first  bicuspids  been  extracted,  many  difficulties  in  the  regu- 
lation  of  the   teeth   would   have  been   removed  ;  and  what  is   of   far 


PHYSIOGNOMY  AND  THE  SAVING   OF  TEETH. 


827 


greater  importance,  there  Avould  have  been  a  satisfactory  result  in  the 
dental  arch  and  physiognomy.  Or  even  further,  had  the  upper  first 
bicuspids  been  extracted  as  soon  as  they  erupted,  together  with  the 
deciduous  canines,  as  will  be  outlined  in  the  second  phase  of  the  subject, 
the  case  would  have  required  little  or  no  other  treatment. 

Fig.  879  shows  the  present  position  of  teeth  after  regulation,  by  re- 
truding  the  anterior  teeth  to  fill  spaces  caused  by  the  extraction  of  the 
bicuspids.     Fig.  880  is  from  a  model  of  the  face  after  treatment.     It 


Fig.  881. 


will  be  seen  that  the  interproximal  spaces  between  the  teeth  are  restored, 
while  the  retrusion  of  the  anterior  teeth  allows  the  lips  to  fall  gracefully 
into  proper  position.  The  improvement  in  the  facial  aspect  of  this  and 
all  other  cases  cannot  be  fully  shown 
by  a  plaster  model  of  the  face.  Fig. 
881  was  made  from  a  photograph  of 
this  patient,  taken  a  few  months  after 
the  completion  of  treatment. 

There  are  many  instances  where  the 
early  extraction  of  the  bicuspids,  as  soon 
as  they  can  be  reached  with  the  forceps, 
is  demanded. 

For  example,  adult  faces  with  ab- 
normal protruding  upper  jaws  and 
teeth,  and  with  a  bulged  appearance 
about  the  lower  portion  of  the  nose 
should  have  been  thus  treated.  The  teeth  are  commonly  large,  prom- 
inent, and  crowded,  though  not  always  labially  inclined. 

The  ordinary  upper   protrusions  which  come  under  this  head  are 
so  common  they  will  require  no  further  explanation  or  illustration. 

Upper  protrusions  where  the  teeth  are  not  labially  iucliued  are  not 
quite  so  common. 


lfe»^ 


828       THE  DEVELOPMENT  OF  ESTHETIC  FACIAL  CONTOURS. 


The  alveolar  arch  is  necessarily  prominent,  though  the  deformity  in 
the  main,  as  in  the  more  common  iorms  of  ])rotrusion,  is  due  to  the 
large  size  of  the  upper  maxilla  proper,  far  out  of  proportion  to  the 
more  delicately  chiseled  features  which  it  sup})orts  and  forces  into  unsym- 
metrical  contours.  The  depressions  in  which  the  wings  of  the  nose  rest 
are  more  or  less  obliterated,  as  would  be  occasioned  by  the  sting  of  a 
bee  or  an  alveolar  abscess.  The  nostrils  are  broad  and  open,  and  the 
end  of  the  nose  forced  forward  and  upward  (retrousse)  by  the  protrusion 
of  the  spinous  process  and  cartilaginous  septum.  The  upper  lip  being- 
stretched  over  its  inharmonious  frame  is  shortened  so  as  to  cover  the 
teeth  with  difficulty,  and  in  action  readily  rises  to  an  unpleasant  ex- 
posure of  the  teeth  and  gums. 

This  is  an  extreme,  though  not  uncommon,  condition.  Every  stage 
from  this  to  perfect  harmony  characterizes  the  innumerable  varieties  of 
a  certain  type  of  physiognomy. 

Fig.  882  is  from  the  face  model  of  a  young  man,  eighteen  years  of 
age,  and  may  be  taken  as  a  type  of  this  character  of  facial  deformity. 


Fig.  882. 


Fig.  883. 


Fig   883  shows  the  teeth  in  occlusion.     The  canines  and  canine  emi- 
nences are  very  prominent,  and  extend  high  up  under  the  wings  of  the 


nose. 


Had  this  case  received  the  early  treatment  here  advocated,  the 
deformity  would  have  been  prevented  and  the  almost  insurmountable 
difficulties  attending  its  reduction  during  nearly  three  years  of  constant 
treatment  altogether  avoided. 

Any  one  who  has  never  attempted  to  move  the  roots  of  the  canines 
in  a  posterior  direction  for  patients  older  than  sixteen  cannot  begin  to 
appreciate  the  difficulties  of  such  an  operation. 

And  while  the  result  is  quite  satisfactory  under  the  circumstances, 
as  will  be  seen  by  Figs.   884  and  885,  the  physiognomy  is  not  nearly 


PHYSIOGNOMY  AND  THE  SAVING   OF  TEETH. 


829 


so  perfect  esthetically  as  it  would  have  been  had  the  case  received  proper 
early  treatment. 

The  important  consideration  from  a  surgical  and  artistic  standpoint 
in  nearly  all  cases  of  abnormal  upper  protrusion  is  :  Has  not  Nature 
been  forced  to  produce  these  conditions,  wholly  or  in  part,  to  accommo- 
date teeth  that  were  too  large  for  the  natural  or  inherent  frame  and 
overlying  features  ?  And  could  we  have  helped  Nature  in  the  early 
years  of  development,  by  making  it  unnecessary  for  her  to  produce  this 
excessive  growth  of  bone  for  the  development  and  sustenance  of  all 
these  large  teeth? 

The  same  is  true  where  the  protrusion  seems  to  have  been  caused 
by  the  inheritance  of  an  inharmoniously  large  jaw  crowded  full  of 
teeth. 

We  certainly  cannot  reduce  the  size  of  the  teeth,  but  we  can  reduce 
their  number,  and  in  so  doing  reduce  the  size  of  the  destined  maxillary 


Fig.  8S4. 


Fig.  885. 


and  dental  arch.  But  we  must  make  no  mistake.  The  danger  of  ad- 
vocating such  a  principle  to  those  who  have  given  this  branch  of  den- 
tistry little  thought  is  that  teeth  will  be  extracted  to  accommodate  an 
overcrowded  condition  in  the  arch,  with  little  or  no  thought  of  the 
physiognomy,  when  a  careful  and  properly  pursued  stiidy  of  the  features 
and  their  comparison  with  the  parental  types  will  show  that  in  reality 
the  dental  and  maxillary  arch  should  be  enlarged,  and  every  tooth  re- 
main to  induce  its  natural  growth  and  development.  If  this  has  not 
been  attained  by  natural  processes,  every  tooth  should  certainly  remain 
to  hold  the  artificially  developed  arch  in  place. 

How  are  we  to  study  the  undeveloped  face  of  a  child,  every  linea- 
ment of  which  is  passing  through  rapid  changes  of  growth,  with  a  view 
of  determining  whether  or  not  the  dental  arch  and  jaws  will  be  too 
prominent,  or  that  other  features  will  not  enlarge  to  a  harmonizing 
proportion  ? 


830       THE  DEVELOPMENT  OF  ESTHETIC  FACIAL  CONTOURS. 

A  most  wonderful  provision  of  Nature  iu  dentition  causes  the  full- 
sized  crowns  of  teeth  to  erupt,  as  regards  time,  somewhat  in  proportion 
to  the  natural  growth  and  enlargement  of  the  jaws.  And  even  when 
they  do  not  erupt  earlier  than  is  normal,  or  Avhen  their  natural  eruption 
is  not  interfered  with  by  the  prematur(>  extraction  of  the  deciduous 
teeth,  they  arc  usually  obliged  to  take  an  irregular  position  or  attitude 
at  first,  and  await  the  growth  of  the  jaw  which  permits  them  to  become 
regular. 

It  is  perhaps  a  safe  general  rule  to  never  extract  a  permanent  tooth 
for  the  purpose  alone  of  correcting  a  dental  irregularity,  unless  the  jaw 
has  ceased  growing ;  and  never  then  unless  it  is  shown  by  a  careful  study 
of  the  position  of  the  teeth — their  relation  and  occlusion — that  the  den- 
tal arch  should  not  be  expanded ;  or  by  a  study  of  the  j^hysiognomy, 
that  the  alveolo-dental  arch  should  not  be  enlarged. 

In  a  study  of  the  relations  of  the  teeth,  the  jaws,  and  the  physiog- 
nomy of  a  child  with  the  view  of  determining  the  advisability  of  extrac- 
tion to  correct  or  prevent  the  ultimate  production  of  a  facial  deformity 
or  marked  imperfection  of  the  features,  it  may  become  necessary  to 
study  the  physiognomies  of  both  parents  and  possibly  other  members 
of  the  family,  to  correctly  determine  the  influence  of  inheritance. 

In  this  comparison  of  temperament,  physical  frame,  features,  and 
teeth,  it  may  require  no  more  than  a  glance  to  furnish  all  the  data  that 
will  be  of  practical  use. 

Usually  but  one  parent  accompanies  the  little  patient,  and  a  study 
of  that  one  physiognomy  may  be  a  sufficient  guide ;  if  not,  other  mem- 
bers of  the  family  should  be  seen. 

If  there  be  a  marked  difference  in  the  parents  it  may  not  be  difficult 
to  determine  from  which  the  child  has  inherited  the  teeth,  by  the 
peculiar  shape  and  size  of  the  incisors  alone.  But  in  regard  to  the 
maxillje  in  an  undeveloped  condition  there  will  be  more  difficulty, 
though  it  is  well  to  remember  that  the  deciduous  teeth  are  rarely  irregu- 
lar or  disproportionate  in  size  to  the  frame  and  facial  features.  If,  there- 
fore, there  be  a  more  than  natural  difference  in  the  size  of  the  permanent 
and  deciduous  teeth  it  will  indicate  union  of  inharmonious  types. 

In  this  connection  it  must  not  be  forgotten  that  the  crowns  of  the  per- 
manent incisors  are  almost  invariably  far  too  large  for  their  undevel- 
oped surroundings.  The  apparently  disproportionate  size  of  the  cen- 
tral incisors  to  that  of  the  jaw  is  a  subject  of  frequent  and  anxious 
parental  comment.  If  the  occlusion  of  the  incisor  teeth  be  far  from  a 
normal  type  in  their  anterior  relations,  and  the  same  condition  exists 
with  either  parent,  it  is  an  indication  of  what  the  child  will  become  if 
unaided  by  dental  skill,  especially  if  a  similarity  be  noted  in  other 
particulars. 


PHYSIOGNOMY  AND  THE  SAVING   OF  TEETH.  831 

With  differences  in  temperament,  compare  general  shape  and  size  of 
the  eyes,  brows,  ears,  and  teeth. 

Other  features  are  so  subject  to  change  in  the  processes  of  natural 
growth  and  development  that  they  cannot  be  relied  upon  to  furnish 
legitimate  data.  For  instance,  the  nose  may  change  in  a  few  years 
of  late  youthful  development  from  one  originally  small  and  short — 
and  over  the  nasal  bones  decidedly  depressed — to  a  form  different  in 
every  particular. 

When  neither  parent  presents  the  same  unsym metrical  relations  that 
promise  to  prevail  in  the  child,  the  cause  may  be  a  union  of  the  large 
teeth  of  one  parent  with  the  small  jaws  of  the  other. 

When  the  teeth  of  the  parents  are  decidedly  dissimilar  in  size,  it 
may  be  possible,  as  before  stated,  to  determine  with  certainty  from 
which  parent  the  teeth  of  the  child  are  inherited,  and  when  the  teeth 
and  jaws  of  the  other  parent  are  small  and  other  features  are  similar 
to  those  of  the  child,  it  indicates  a  union  of  undiluted  types. 

All  these  things  are  of  the  utmost  importance  in  determining  the 
impropriety  of  extracting  certain  teeth  to  reduce  an  apparent  abnormal 
protrusion,  which  may  in  time  become  symmetrical  in  its  relation  by 
the  natural  growth  of  the  jaws  and  other  features  ;  and  also  the  equally 
culpable  error  of  saving  teeth,  or  the  failure  to  extract  teeth,  whose 
very  presence  in  the  arch  obliges  Nature  to  reproduce  a  parental 
deformity,  or  produce  an  acquired  deformity,  by  an  effort  to  sustain  the 
large  teeth  of  one  parent  in  conjunction  with  the  small  jaws  of  the 
other. 

For  a  child  with  an  abnormal  upper  protrusion  similar  to  Figs.  886 
and  887,  with  teeth  prominent  and  crowded  in  an  arch  which  does  not 
Fig.  886.  Fig.  887. 


admit  of  correcting  by  a  lateral  expansion,  extract  the  first  bicuspids  as 
early  as  possible,  even  before  their  eruption  is  completed,  together  with 
the  deciduous  canines — imless  it  be  one  of  those  very  rare  instances 
where  the  first  permanent  molars  cannot  be  saved. 


832       THE  DEVELOPMENT  OF  ESTHETIC  FACIAL  CONTOURS. 


The  same  is  true  of  the  lower,  when  there  is  reason  to  believe 
there  will  be  a  disproportionate  over-development  of  the  lower  dental 
arch. 

In  the  ordinary  course  of  eruption  the  development  and  eruption  of 
the  permanent  canines  are  doubtless  more  influential  than  those  of  other 
teeth  in  emphasizing  an  anterior  protrusion  of  the  central  features  of 
the  physiognomy. 

In  the  course  of  their  eruption  they  are  obliged  to  crowd  into  align- 
ment alone;  the   mesial  surfaces  of  the  roots  and  crowns  of  the  first 


Fk;.  888. 


Fig. 


Fig.  890. 


bicuspids — which  at  this  time  represent  the  immovable  bases  of  the 
arch — with  the  result  that  the  incisive  and  intermaxillary  portion  of 
the  arch  is  forced  forward  to  a  more  pronounced  position.  This  move- 
ment has  been  shown  to  be  not  impossible  or  difficult  of  attainment  by 
artificial  force,  even  much  later  in  life. 

With  the  first  bicuspids  and  deciduous  canines  removed  sufficiently 
early  there  are  numberless  instances  when  the  arch,  anterior  to  the 

second  bicuspids,  would  be  diminished  the 
width  of  a  bicuspid,  without  resort  to  arti- 
ficial means. 

By  the  exertion  of  a  slight  traction  force 
from  an  occipital  base  of  anchorage  the 
sockets  of  the  temporary  canines  will  be 
closed  by  the  permanent  laterals,  and  the 
permanent  canines  in  the  course  of  their 
eruption  will  be  deflected  into  the  alveoli 
of  the  extracted  bicuspids. 

Figs.  888  and  889  represent  one  case  out 
of  many  under  treatment  by  this  method, 
though  not  all  by  the  occipital  method. 
Fig.  890  shows  the  position  of  the  teeth  after  about  two  months 


THE  CONTOURING  APPARATUS.  833 

of  traction  force  from  molar  anchorages ;  the  protrusion  not  being  so 
pronounced  as  to  demand  the  use  of  the  skull-cap. 

It  will  be  seen  by  the  canine  eminences — though  far  better  shown 
upon  the  model  itself — that  the  position  of  the  canine  crowns  is  imme- 
diately over  the  former  alveoli  of  the  first  bicuspids.  As  they  continue 
to  grow  dowuAvard  in  this  somewhat  open  channel,  their  roots,  which 
are  not  at  present  developed,  will  grow  upward,  the  teeth  in  their  en- 
tirety finally  taking  a  position  and  inclination  similar  to  that  of  the 
bicuspids  which  they  replace,  and  considerably  posterior  to  that  which 
they  were  otherwise  destined  to  occupy. 

The  patient,  nine  years  of  age,  had  the  teeth,  eyes,  ears,  and  general 
temperament  of  the  father,  whose  upper  arch  was  abnormally  protruded 
in  a  similar  manner,  which  was  the  raison  cVctrc  for  dental  aid. 

Had  the  father's  teeth  been  in  proper  relative  and  symmetrical 
position,  and  similar  to  the  son's  in  other  particulars  which  could  be 
legitimately  used  as  data,  it  would  have  been  an  argument  in  favor 
of  non-extraction  with  the  expectation  of  other  treatment  later ;  but 
it  should  not  have  been  passed  upon  without  seeing  the  mother.  Had 
the  mother's  teeth  been  found  small  and  the  general  physical  features 
cast  in  a  more  delicate  mould  than  her  husband's,  investigations  along 
other  lines  would  have  been  required  with  the  view  of  determining 
if  the  child  had  not  the  large  teeth  of  the  father  and  small  jaws  of  the 
mother ;  in  which  case  extraction  would  also  have  been  indicated. 

VI.  The  Contouring  Apparatus. 

The  limited  area  upon  which  force  can  be  applied  to  a  tooth,  com- 
pared with  that  portion  covered  by  the  gum  and  imbedded  in  a  bony 
socket,  has  made  it  next  to  impossible,  with  all  ordinary  methods,  to 
move  the  apex  of  the  root  in  the  direction  of  the  applied  force ;  nor 
could  this  ever  be  accomplished  with  force  exerted  in  the  usual  way  at 
one  point  upon  the  crown,  however  near  the  margin  of  the  gum  it  may 
be  applied,  for  the  opposing  margin  of  the  alveolar  socket  must  receive 
the  greater  portion  of  this  direct  force,  and  in  proportion  to  its  resist- 
ance it  will  become  a  fulcrum  exerting  a  tendency  to  move  the  apex  of 
the  root  in  the  opposite  direction. 

But  if  in  the  construction  of  the  apparatus  a  static  fulcrum  is  created 
independent  of  the  alveolar  process  at  a  point  near  the  occluding  portion 
of  the  crown,  while  the  power  is  applied  at  a  point  as  ftir  upon  the  root 
as  the  mechanical  and  other  opportunities  of  the  case  will  permit,  the 
apparatus  becomes  a  lever  of  the  third  kind,  tlie  power  being  directed 
to  a  movement  of  the  entire  root  in  the  direction  of  the  applied  force. 

This  proposition  is  made  plain  by  reference  to  diagrams.  In  Fig. 
891  let  A  be  a  point  upon  a  central  incisor  at  which  force  is  applied  in 

53 


834       THE  DEVELOPMENT  OF  ESTHETIC  FACIAL   CONTOURS. 


the  direction  iiulicated  l)y  the  arrow,  theii  will  the  <)i)p().sing  wall,  i;,  of 
the  alveolar  socket  near  its  margin  receive  nearly  all  of  the  direct  force  ; 
and  in  j)roportion  to  its  resistance  will  there  be  a  tendency  to  move  the 
root  in  the  o])j)osite  direction.  This  will  also  hold  good  even  if  the 
force  be  applied  at  a.  Fig.  892,  or  as  I'ar  upon  the  root  as  may  be  per- 
mitted by  attaching  a  rigid  npright  bar,  c,  to  the  anterior  surface  of  the 


B-^ 


crown  ;  the  only  difference  being  that  the  direct  force  is  distributed 
over  a  greater  area.  But  if,  as  in  Fig.  893,  to  the  lower  end  of  c  a 
traction  wire  or  bar,  f,  is  attached  and  if  the  mechanical  principles  of 
the  machine  be  further  enforced  by  uniting  its  posterior  attachment  to 
the  anchorage  of  the  power  bar,  p,  the  anchorage  force  will  be  materially 
neutralized  and  an  independent  static  fulcrum  at  d  created.  The  appa- 
ratus now  will  distribute  its  force  over  the  entire  root,  and  give  com- 
plete direction  and  control  of  whatever  power  is  put  into  it.     The 


Fig.  893. 


entire  tooth  may  be  carried  forward  bodily  or  either  end  may  be  made 
to  move  the  more  rapidly.  The  force  thus  directed  to  the  ends  of  the 
roots  will  have  an  increased  tendency  to  move  the  more  or  less  yielding 
bone  in  which  they  are  imbedded. 

For  practical  illustrations  of  what  has  been  accomplished  by  an 
apparatus  of  this  kind  see  cases  described  in  sections  I.,  IV.,  and  V.  of 
this  chapter. 

The  contouring  apparatus  is  made  entirely  of  German  silver,  with 
the  exception  of  the  nuts,  which  are  of  nickel.  German  silver  is  pre- 
ferred, not  because  it  is  cheaper  than  gold  and  platinum,  but  because  it 


THE  COSTOUBISG  APPABATUS.  835 

possesses  certain  qualities  which  render  it  adapted  for  the  purpose  to 
which  it  is  applied. 

In  making  the  banding  material  for  this  apparatus,  thoroughly  an- 
neal a  piece  of  wire  No.  13  and  pass  it  through  the  rollers — with  an 
occasional  re-annealing — until  it  is  reduced  in  thickness  to  Nos.  35  and 
38  (or  0.004  and  0.0056  of  an  inch).i  This  will  give  bands  about  i  and 
Y^^  of  an  inch  wide.  Use  the  thinner  material  for  the  anterior  teeth 
and  the  thicker  for  the  anchorage  appliance.  Before  using,  it  should  be 
wound  into  rolls  and  brought  to  an  even  red  heat,  held  there  for  ten 
minutes,  then  allowed  to  cool  slowly.  This  will  ensure  perfect  softness 
and  adaptability. 

In  taking  the  measurements  for  the  bands,  cut  from  the  material 
the  proper  length,  and,  holding  the  ends  of  the  loop  between  thumb  and 
finger,  pass  it  over  the  tooth  to  be  fitted.  When  in  place  bend  the  ends 
sharply  at  right  angles  and  finally,  grasping  the  two  ends  in  the  pliers, 
draw  the  band  firmly  around  the  tooth.  The  bands  for  the  anterior 
teeth  should  extend  at  this  time  sufficiently  beneath  the  approximal  bor- 
ders of  the  gum  to  assure  complete  extension  to  the  labio-  and  linguo- 
gingival  borders.  The  approximal  extension  should  be  cut  down  to  the 
gingival  border  of  the  enamel  in  the  final  finishing  of  the  apparatus. 

After  the  bands  are  soldered  carefully,  fit  and  burnish  them  to  the 
teeth.  In  order  to  obtain  perfect  adaptation  it  often  becomes  necessary 
to  contour  them  slightly  with  the  proper  pliers.  The  joint  which  pro- 
jects on  the  anterior  surface  of  the  bands  for  the  anterior  teeth  should 
be  placed  at  one  side  of  the  middle  to  allow  the  upright  bar  c.  Fig.  893, 
to  rest  exactly  along  the  median  line. 

When  the  teeth  are  so  crowded  together  that  the  banding  material 
cannot  be  passed  freely  between  them  they  should  first  be  separated 
with  waxed  tape.  It  is  to  be  preferred  to  rubber  because  sufficient 
space  is  obtained  in  twenty-four  hours  with  little  or  no  discomfort  to 
the  patient  beyond  the  general  soreness  of  the  teeth,  Avhich  must  always 
follow  the  preliminary  steps  of  a  regulating  operation.  These  tapes 
are  allowed  to  remain  between  the  teeth — renewing  them  each  day — till 
the  final  attachment  of  the  apparatus. 

The  first  appliance  to  be  described  is  that  designed  for  moving  the 
roots  of  the  upper  incisors  forward. 

Before  it  is  possible  to  apply  the  contouring  force  it  is  frequently 
necessary  to  first  move  the  crowns  of  very  irregular  teeth  into  aligu- 
ment  somewhat — and  even  to  rotate  them — so  as  to  bring  them  into  a 
position  to  be  properly  grasped  by  the  power  bar  of  the  apparatus. 
(See  Fig.  872,  with  description.) 

^  In  tliis  description  it  will  be  nnderstood  that  German  silver  is  the  metal  indicated 
and  Brown  &  Sharp's  gange  that  by  which  thicknesses  are  measured. 


836       THE  DEVELOPMENT  OF  ESTHETIC  FACIAL   CONTOURS. 

When  the  bands  have  been  fitted  as  described  above,  they  should  be 
phiced  upon  the  four  incisors  and  a  plaster  impression  taken  of  the 
labial  surfaces  of  the  bands,  teeth,  and  adjoining  gum.  For  a  tray  to 
carry  the  plaster  to  place  use  a  thin  piece  of  lead  cut  the  proper 
size. 

After  the  impression  is  removed,  carefully  remove  the  bands  and 
place  them  in  their  respective  positions  on  the  impression  ;  the  joints 
of  the  bands  will  serve  to  guide  them  to  place.  This  when  filled  with 
Teague's  or  other  investing  material  will  give  a  model  with  the  bands 
in  position,  to  which  may  be  fitted  and  soldered  the  upright  bars. 

The  upright  bars  are  made  of  No.  14  wire,  bent  to  fit  the  anterior 
face  of  the  band  and  tooth  along  the  median  line  of  its  axis,  and  also 
the  gum  to  about  ^  of  an  inch  above  its  margin.  In  soldering  them  to 
the  bands,  completely  fill  the  V-shaped  spaces  on  either  side  the  upright 
bars,  to  give  sufficient  rigidity  and  finish  to  the  appliance.  After  they 
have  been  soldered  and  removed  from  the  model  they  are  further  finished 
by  filing  the  bars  flat  on  the  sides  which  lie  next  to  the  gum,  tapering 
them  to  one-half  tlieir  diameters  at  the  upper  ends.  It  is  against  this 
surfiice  that  the  power  bar,  P,  is  to  rest,  as  shown  in  Fig.  893.  The 
upright  bar  may  also  be  flattened  somewhat  over  the  face  of  the  tooth, 
but  not  at  the  point  where  it  leaves  the  band  for  the  gum,  as  full 
strength  and  rigidity  are  required  here.  (In  Fig.  893  the  engraver  has 
made  the  upright  bar  appear  far  too  light  at  this  point — marked  c — for 
practical  use  in  sustaining  the  great  force  of  the  power  bar  at  b.) 

The  bars  having  been  cut  off  even  with  the  occluding  ends  of  the 
teeth,  and  properly  rounded  and  polished,  the  small  transverse  grooves, 
D,  may  be  cut  just  above  the  ends  to  receive  the  fulcrum  wire,  F,  No. 
24  gauge,  which  is  much  smaller  tlian  shown  in  Fig.  893. 

In  constructing  the  anchorage  portion  of  the  apparatus  to  be  attached 
to  the  posterior  teeth  too  much  care  cannot  be  observed  in  order  that 
the  several  parts  perform  the  work  assigned  to  them  and  the  greater 
portion  of  force  be  neutralized  at  points  of  anchorage. 

When  the  second  molars  have  fully  erupted,  band  the  first  and 
second  molars — otherwise  the  second  bicuspids  and  first  molars — and 
sometimes  all  three  teeth.  AVhere  it  becomes  advisable  to  apply  this 
particular  form  of  force  before  the  eruption  of  the  second  bicuspids, 
the  second  deciduous  and  first  permanent  molars  will  answer  for  the 
purpose. 

The  banding  material  should  be  as  wide  as  the  tooth  will  permit, 
and  in  thickness  from  Nos.  36  to  35  (or  0.005  to  0.0055  of  an  inch). 
When  the  bands  have  been  made  as  described  and  perfectly  fitted,  place 
them  in  the  positions  they  are  to  occupy  and  take  a  plaster  impression 
— one  side  at  a  time — allowing  the  plaster  to  barely  cover  the  bands. 


THE  CONTOURING    APPARATUS. 


837 


but    sufficiently   extensive   to   show   on    the   model  the   bicuspids    and 
canines,  for  reasons  that  will  become  obvious. 

After  removal,  replace  the  bands  accurately  in  their  positions  in  the 
impression,  and  fill  as  before  with  Teague's  or  any  good  investing 
material. 

This  material  will  give  a  model  that  will  hold  the  bands  in  exact 
relative  position  while  they  are  being  soldered,  and  one  also  that  is  suf- 
ficiently extensive  to  enable  the  placing  and  soldering  of  the  tubes  in 
proper  position  and  direction — a  thing  of  the  utmost  importance. 

In  selecting  the  tubes  the  smaller  should  loosely  fit  the  threaded  end 
of  No,  20  wire,  which  is  the  size  to  use  for  the  fulcrum  wire,  f.  The 
size  of  the  larger  tube  should  be  governed  by  the  size  of  the  power  bar, 
i.  e.  when  the  jaw  is  large  with  fully  developed  teeth,  or  when  the  dis- 
tance is  considerable  from  anchorage  appliances  to  the  upright  bars  on 
the  anterior  teeth,  the  size  of  the  power  bar,  p,  should  be  No.  14.  It 
should  rarely  be  smaller  than  No.  15,  though  when  the  operation  is 
attempted  for  very  young  children  No.  16  will  answer  the  purpose. 
But  the  ordinary  German-silver  wire  of  the  shops  of  these  sizes  will 
not  do.  It  must  be  specially  prepared  in  order  to  withstand,  without 
bending,  the  great  force  exerted  upon  a  bent  bow  or  bar.  All  wire  for 
power  bars  should  be  drawn,  without  annealing,  from  No.  6,  and  be 
nearly  as  rigid  as  tempered  steel.  In  the  selection  of  tubes  the  larger 
should  loosely  fit  the  threaded  end  of  the  power  bar,  and  be  ^  to  f  of 
an  inch  long. 

An  important  feature  is  the  position  of  the  power-bar  tubes.  They 
should  be  so  placed  and  soldered  to  the  anchorage  bands  that  the  power 
bar — when  placed  in  the  tubes — will  ex- 
tend from  it  in  a  straight  line  to  the  ca- 
nines, where  it  bends  over  to  engage  with 
the  upright  bars,  c.  (See  Fig.  893.)  If 
this  precaution  be  not  taken,  but  instead  the 
power  tubes  are  soldered  in  the  ordinary 
way,  in  contact  with  the  buccal  surfaces  of 
the  bands,  the  power  bow,  in  most  instances, 
will  require  to  commence  its  encircling  bend 
immediately  upon  emerging  from  the  tubes, 
with  a  decided  weakening  of  its  rigidity  and 
possible  fiiilure. 

In  order  to  obtain  the  proper  position 
it  will  often  be  advisable  to  rest  the  poste- 
rior end  of  the  larger  tube  upon    that  of 

the  smaller,  as  shown  in  Figs.  894  and  895.     All  projecting  portions 
that  are  liable  to  irritate  the  mouth  should  be  rounded  and  polished. 


Fig.  894. 


838       THE  DEVELOPMENT  OF  ESTHETIC  FACIAL  CONTOURS. 

In  solderint>-  tubes  to  place  use  a  .slightly  lower  grade  of  silver  solder 
than  that  used  to  join  the  bands.  Use  sufficient  to  thoroughly  unite  all 
the  joints,  and  fill  all  V-shaped  spaces,  being  careful  to  turn  the  joints 
of  the  tubes  toward  the  bands  that  they  may  be  closed.  Thoroughly 
unite  the  api)roxiiiKd  surfaces  of  the  bands  and  reinforce  the  lingual  V 
with  an  extra  piece.     (See  Fig.  894.) 

In  finishing  the  apparatus,  the  soldered  parts  should  be  boiled  in  a  solu- 
tion of  sulfuric  acid  to  remove  the  borax  and  oxids.  After  being  neu- 
tralized and  brushed  they  are  now  ready  for  the  trial  fitting  to  the  mouth. 

In  this  operation  the  bands  should  be  perfectly  fitted  to  the  position 

Yic.  895. 


Protrusion  apparatus. 

they  are  to  occupy — the  upright  bars  readjusted,  if  necessary,  and  all 
surplus  material  cut  away — sharp  and  rough  surfaces  smoothed  and 
polished,  and  the  gingival  and  occluding  edges  of  the  bands  carefully 
burnished  to  the  teeth. 

In  constructing  the  power  bar  the  anchorage  attachments  should  be 
placed  upon  a  plaster  model  of  the  teeth,  in  order  to  accurately  deter- 
mine its  length  and  the  lengths  of  its  threaded  ends,  then  properly 
shaped  to  the  gum  over  which  it  is  to  rest.  It  should  be  flattened  in 
the  rollers  to  about  one-half  its  diameter  along  that  portion  which  lies 
in  front  of  the  bicuspids.  In  this  operation  it  may  become  necessary 
to  roll  the  bar  so  that  the  bent  bow  is  flaring,  to  fit  the  gums  against 
which  it  nearly  rests,  and  to  engage  perfectly  with  the  upright  bars — 
especially  if  the  incisors  are  labially  inclined. 

When  the  apparatus  is  polished  and  heavily  gold-plated  it  is  ready 
for  the  final  cementing  to  the  teeth.    Brush  the  teeth  with  piunice  stone, 


THE  CONTOURING  APPARATUS.  839 

place  a  napkin  in  the  mouth,  and  dry  the  teeth  and  surrounding  gum 
with  spunk.  Pack  it  around  the  teeth,  where  it  is  hekl  firmly  in  posi- 
tion while  the  cement  is  being  prepared  and  placed  in  the  bands  by  an 
assistant.  See  that  all  material  used  in  polishing  is  removed  from  the 
inner  surface  of  the  bands,  and  the  surface  scraped  or  scratched  with  a 
sharp  excavator. 

The  cement  should  be  mixed  thoroughly,  but  rapidly,  to  the  con- 
sistence of  thick  cream,  and  scraped  from  the  spatula  along  the  upper 
and  inner  edges  of  the  bands. 

When  each  part  of  the  appliance  is  ready,  force  it  quickly  and  firmly 
to  its  position ;  its  final  adjustment  being  perfected  by  the  use  of  the 
mallet  on  a  large  oval  plugger  resting  upon  the  soldered  parts. 

After  the  anchorage  attachments  have  been  cemented  in  place,  make 
an  appointment  for  the  next  day  to  attach  the  remainder  of  the  appa- 
i-atus,  in  order  to  allow  the  cement  to  become  perfectly  hardened,  that 
the  bands  may  not  be  dislodged,  or  even  slightly  started,  by  the  strain 
to  which  they  are  subjected  in  the  final  adjustment  of  the  power  bar. 

Another  way  is  to  adjust  the  anchorage  attachments  to  the  ends  of 
the  power  bar — out  of  the  mouth — after  the  parts  have  been  perfected, 
shaped,  and  fitted — and  cement  the  whole  to  place  in  this  condition. 
By  this  method  the  whole  apparatus  can  be  attached  to  the  teeth  at  one 
sitting. 

On  account  of  the  intense  rigidity  of  the  poAver  bar  it  is  important 
that  when  it  is  in  j)lace  on  the  teeth  tlie  threaded  ends  should  lie  within 
their  respective  anchorage  tubes  without  exerting  the  slightest  force  in 
any  direction  until  it  is  applied,  as  intended,  by  the  power  of  the  screws  ; 
therefore  great  care  should  be  observed  in  giving  to  it  the  proper  shape, 
by  bending  as  accurately  as  possible  upon  the  plaster  model,  and  after- 
ward by  a  trial  fitting  in  the  mouth  before  cementing  the  anchorage 
bands. 

With  the  ancliorage  attachments  and  power  bar  in  position  the  bands 
are  to  be  cemented  to  the  anterior  teeth.  As  eacli  band  is  carried  to  its 
place,  it  should  be  seen  that  the  flattened  surface  of  the  upright  bar  is 
pressed  down  firmly  upon  the  power  bar,  so  that  an  even  force  will  be 
given  to  each  of  the  teeth  when  power  is  applied — it  being  presupposed 
that  in  the  trial  fitting  of  the  parts  the  power  bar  was  shaped  so  as  to 
engage  j)erfectl}'  with  the  upright  bars — the  free  euds  of  the  latter  ex- 
tending slightly  above  it. 

The  same  kind  of  apparatus  may  be  employed  upon  the  lower  in- 
cisors with  perfect  success,  though  there  will  not  be  the  same  tendency 
to  carry  the  entire  alveolar  ridge  forward  with  the  roots  as  on  the 
upper ;  the  change  being  largely  by  a  metamorphosis  of  alveolar  tissue. 

An  apparatus  for  contruding  the  roots  of  the  anterior  teeth  is  con- 


840       THE  DEVELOPMENT  OF  ESTHETIC  FACIAL  CONTOURS. 

structed  in  a  vcrv  similar  manner.  The  direction  of  the  two  forces 
being  reversed,  it  becomes  necessary,  however,  to  make  certain  import- 
ant variations.  The  power  bar  (i',  Fig.  896)  now  exerting  a  traction 
force,  No.  IG  will  he  fonnd  sufficiently  large  for  all  purjjoses.  It  is 
not  flattened,  bnt  rests  in  grooves  cnt  in  the  anterior  surfaces  of  the 

Fig.  896. 


upright  bars,  B.  The  power-bar  tubes  should  be  soldered  closely  to  the 
anchorage  bands  so  that  the  nuts  which  now  work  at  the  posterior  ends 
of  the  bar  will  not  irritate  the  mucous  membrane  of  the  cheek.  The 
fulcrum  bar,  f,  exerting  in  this  apparatus  a  jack-screw  force,  should  be 


No.  16.  It  is  flattened  along  its  middle  portion  to  engage  with  the 
occluding  ends  of  the  upright  bars  at  d,  provision  being  made  for  the 
purpose   in  the  construction. 

The  power  of  the  two  forces  being  so  great  upon  the  upright  bars, 
with  a  tendency  to  lift  the  occluding  ends  from  their  attachments,  and 
thus  allow  the  free  ends  to  press  into  the  gum,  it  is  important  with  this 
apparatus  that  the  occluding  end  attachments  be  reinforced  by  soldering 


THE  CONTOURING  APPARATUS.  841 

to  the  bands  an  extra  piece  of  banding  material  that  shall  extend  from 
the  labial  face  over  the  occluding  end  of  the  tooth  to  the  lingual  portion 
(shown  in  Fig.  897). 

After  the  joint  of  the  band  has  been  soldered,  the  reinforcing  piece, 
of  sufficient  length  for  the  purpose,  should  first  be  soldered  to  the  labial 
face  alongside  of  the  joint ;  then  the  band  is  perfectly  fitted  to  the 
natural  tooth — the  extra  piece  being  bent  over  and  burnished  to  its 
position  on  the  labial  surface,  and  the  position  of  its  end  distinctly 
marked  upon  the  band,  to  serve  as  a  guide  to  soldering, 

AVhen  the  hoods  are  completed  in  this  way  and  finally  all  placed  on 
the  tooth  and  perfectly  fitted,  an  impression  should  be  taken  for  fitting 
and  soldering  the  upright  bars  as  described  for  the  protrusion  apparatus. 


INDEX. 


ABSCESS,  alveolar,  in  deciduous  teeth, 
680 
chronic,  with  fistulous  opening,  497 

treatment  of,  495 
dento-alveolar,  479 
opening  of,  494 
treatment  of,  496 
Acid  conditions  of  the  oral  fluids,  effect  of, 

191 
After-treatment  of  pulp  exposure,  415 
Age,  relation  of,  to  pyorrhea,  527 
Air,  admixture  of,  with  nitrous  oxid,  631 
Albumin,  action  of  mercuric  chlorid  on, 

435 
Albuminous  food,  use  of,  in  pyorrhea,  530 
Alcohol,  use  of,  in  pulp  treatment,  426 
Alkalies,  action  of,  on  dental  pulp,  434 
use  of,  in  treatment  of  sensitive  dentin, 
194 
Alkaline  waters,  use  of,  in  pyorrhea,  530 
Alkalithia,  530 
Alloy  and  cement  fillings,  367 
Alloys,  aging  of,  253,  308 
Alum,  use  of,  in  pulp  devitalization,  441 
Aluminum  amalgam,  314 
Alveolar  abscess,  479 

at  bifurcation  of  roots,  499 
brain  infection  from,  586 
causes,  479 
chronic,  486 
clinical  history,  485 
complications  of,  500 
diagnosis  and  prognosis,  487 
pathology  and  morbid  anatomy,  480 
treatment,  489 
process,  absorption  of,  in  pyorrhea,  524 
accidents  to,  after  extraction,  612 
anatomy  of,  577 
necrosis  of,  637 
resorption  of,  578 
ridge,  bending   of,  in  regulating   teeth, 
698 
Alveoli,   enlargement  of,  from   regulating 

appliances,  701 
Alveolo-dental  membrane,  91,  135 
Amalgam  as  a  cavity  lining,  258 
and  gold  fillings,  354 
first  use  of,  as  filling  material,  305 
"flow"  of,  308 
methods  of  use,  315 
nature  and  properties  of,  306 
objections  to,  255 
proportions  of  ingredients,  252 
use  of,  in  deciduous  teeth,  675 
wafering  of,  677 
war,  305 
washing  of,  314 


Amalgams  as  filling  materials,  255 
classification  of,  312 
binary,  312 
ternar3'-,  313 
quaternary,  314 
combination  of,  361 
composition  of,  252 
contraction  and  expansion  of,  307 
edge  strength  of,  310 
Ambidexterity,  advantages  of,  595 
Ameloblasts,  62,  100 
Ammonia  in  pulp  exposure,  667,  679 
Amyloid,  437 

Anchor  bands  for  regulating,  706 
Anchorages   in   approximal   cavities,   230, 

234,  237 
Anesthesia  by  cataphoresis,  194 
complete,  symptoms  of,  633 
general,  212 
Anesthetics,      general,      examination      of 
patients,  618 
tooth  extraction  under,  617 
local,  and  tooth  extraction,  639 
use  of,  in  planting  teeth,  657 
Angles,  avoidance  of,  in  shaping  cavities, 

220 
Angle's  regulating  appliances,  703,  711 

retaining  appliance,  742 
Annealing  tray,  electric,  275 
Anodes  for  cataphoresis,  205 
Antisepsis  as  related  to  the  plantation  of 
teeth,  164 
in  dentistry,  157 
in  pulp  treatment,  458 
Antiseptic  dressing  for  exposed  pulps,  411 
forceps,  565 
mouth-wash,  458,  514 
Antiseptics  as  sterilizers,  440 

in  pulp  treatment,  433 
Antral  empyema,  501 
Antrum,  drainage  of,  502 

perforation  of,  in  implanting  teeth,  655 
Apical  pericementitis,  treatment  of,  476 
region,  mode  of  entrance  to,  475,  492 
Appliances  used  in  examinations,  174 
Approximal  cavities,  filling  of,  286 
preparation  of,  229 
surfaces,  examination  of,  for  caries,  177 
treatment  of,  262 
in  regulating,  737 
of  cavities  on,  184 
Approximo-incisal  cavity,  234 
Arch,  dental,  18 
normal,  684 
saddle-shaped,  784 
semi-V-shaped,  758 
spreading  of,  754 

843 


844 


INDEX. 


Arch,  dental,  V-shuin'd,  757 

Areas,  eroded,  304 

ArisU)l  as  an  antiseptic,  188,  435 

Arsenic,  action  of,  on  dental  JHilp,  422 
use  of,  in  deciduous  teeth,  (;7'.l 

Arsenous  ucid  in  pulp  devitalization,  421 

Arterial  lieniorrhau;e,  treatment  of,  014 

Arthur's  method  of  tilling,  2G2 

Articular  gout,  521 

Asbestos  ielt,   use  of,    with   silver   nitrate, 
668 

Asepsis,  importance  of,  in  planting  teeth, 
656 

Asphyxia,   avoidance   of,     in  nitrous  oxid 
anesthesia,  625,  631 

Assistant,  necessity  for,  in  nitrous  oxid  ad- 
ministration, 632 

Automatic  mallets,  279 

BACTEKIA  of  pyorrhea,  525 
Balsamo  del  deserto,  438 
in  temporary  teeth,  503 
Band  matrices,  291 
Bands,  regulating,  714,  719 
Basal  layer  of  Weil,  87,  128 

temperaments,  51 
Basic  zinc  cements,  334 
Battery  cells,  arrangement  of,  for  electrical 

osmosis,  198 
Benzoyl  pseudo-tropin,  642 
Bibulous  paper,  use  of,  in  combination  fill- 
ings, 356 
Bicuspids,  earlv  extraction  of,  827 
extraction  of,  603,  606 
microscopical  anatomy  of,  32 
pulp  chambers  of,  447,  448,  450 
Binary  amalgams,  312 
Binoxid  of  tin,  use  of,  in  polishing  teeth, 

181 
Bit,  regulating,  767 
Bite,  jumping  of,  770,  812 

raising  of,  793 
Black's  studies  of  amalgams,  253 
Bleaching  agents,  540 

powder,  care  in  selection  of,  547 
teeth  suitable  for,  542 
Blennorrhea  alveolaris,  509 
Blind  abscess,  495 
Blood  as  an  antiseptic,  656 
Blood-poisoning,  danger  to  operator  from, 

164 
Bonwill's  method  of  amalgam  filling,  320 
Bows  for  regulating,  739,  765 
Brain,  infection  of,  from  suppurating  tooth, 

586 
Breathing,  management  of,  in  nitrous  oxid 

anesthesia,  632 
Broach,  employment  of,  as  pulp  extractor, 

453" 
Bromin  as  an  antiseptic,  434 
Brown  hands  of  Ketzius,  107 
Bryan's  regulating  method,  799 
Buccal  cavities,  filling  of,  283 

preparation  of,  226 
Burnishers,  oiling  of,  360 
Burs,  forms  of,  216 

for  pulp-canal  treatment,  452 


CACHEXIA,   influence   of,    in   alveolar 
abscess,  486 
Calcic  inflammation,  'M) 
Calcific  changes  in  dental  pulp,  417 
Calcification,  process  of,  73 
Calcium  salts,  presence  of,  in  stellate  retic- 
ulum, 66,  83 
Calco-globulin,  73 
Calco-s]iherites,  70,  73 
Callahan's  method  of  pulp  treatment,  462 
Camphor  in  treatment  of  nausea,  248 
Canal  fillings,  essential  ))roperties  of,  436 

treatment,  instruments  for,  452 
Candy,  eftects  of,  on  the  teeth,  681 
Canines,  eruption  of,  690 

extraction  of,  ()02 

macroscopical  anatomy  of,  28 

])n)niinent,  744 

]>ul]i  c'hanibers  of,  447 

rotation  of,  750 
Caoutchouc  as  a  separator,  187 
Cap-and-bit  regulating  appliance,  767 
Capillary  hemorrhage,  treatment  of,  614 
Capping  pulj)s,  methods  of,  411 
Caps,  for  treatment  of  prognathism,  822 

placing  of,  over  exposed  pulp,  412 

swaged,  for  regulating,  704,  714 
Carbolic  acid  as  an  anesthetic,  209 
in  pulp  exposure,  409 
in  i)uli)  treatment,  421 
Caries,  ditferentiation  of,  from  alveolar  ab- 
scess, 488 

due  to  irregularities,  700 

self-limited,  219 
Cataphoresis,  dentinal  anesthesia  by,  194 

technique  of,  203 
Cataphoric  bleaching  methods,  555 
Cathode  electi'ode  for  cataphoresis,  206 
Caustic  pyrozone,  550 
Cavities,  approximal,  filling  of,  671 

classirication  of,  223 

enlargement  of,  for  pulp  treatment,  459 

finishing  margins  of,  223 

occlusal,  filling  of,  669 

preparation  of,  215 

varnishing  of,  360 
Cavitine,  549 

as  a  cavity  lining,  258 
Cavity  lining,  257 

simple,    conversion  of,   into    compound, 
230 

walls,  fracture  of,  302 
Cement  and  alloy  fillings,  367 

and  amalgam  fillings,  351 

and  gold  fillings,  353 

amalgam,  and  gold  fillings,  358 

fillings,  burnishing  of,  360 

fiuids,  instability  of,  338 

lining  for  amalgam  fillings,  323 

paraffin  coating  for,  675 
Cemented  inlays,  369 
Cementoblasts,  143 
Cemento-periostitis,  509 
Cements  as  filling  materials,  255 

use  of,  in  separations,  187 
Cementum,  132 

calcification  of,  86 


INDEX. 


845 


Cervical  margins,  exposure  of,  187 
Chair,  dental,  requisites  for,  594 

form  of,  for  nitrous  oxid  administration, 
G31 
Chart  record  of  examinations,  178 
Children,  treatment  of,  in  the  dental  office, 

666,  669 
Children's  teeth,  operations  on,  502 
Chin,  malpositions  of,  810 
Chisels,  use  of,  in  opening  cavities,  216 
Chlorid  of  silver  cell  battery  for  catapho- 

resis,  202 
Chlorin,  action  of,  on  metals,  547 

as  a  bleaching  agent,  541 

as  a  sterilizer,  434 
Chloroform  as  an  anesthetic,  213 
Chloro-percha  as  a  root-tilling,  438,  446 
Chromic  acid  as  an  anesthetic,  212 
Clamps,  rubber  dam,  244 
Coagulants  in  pulp  treatment,  434 
Coagulation  as  a  chemical  process,  485 
Cobalt  as  a  devitalizing  agent,  424 
Cocain,  antidotes  for,  643 

as  a  local  anesthetic,  639 

cataphoric  use  of,  195,  203 

hypodermatic  injection  of,  640 

in  pulp  treatment,  424 

physiological  effects  of,  640 

relief  of  hypersensitiveness  by,  188,  193 

Schleich's  solution,  642 

toxic  eft'ects  of,  643 
Cocoa  butter  as  a  lubricant,  361 
Coffin  regulating  appliances,  707 

spring  plate,  742 
Cold  as  a  test  of  pulp  exposure,  406 
Color,  stability  of,  in  amalgams,  255 
Combination  fillings,  345 

finishing  of,  357 
Compound  cavities,  combination  filling  of, 
348 
filling  of,  287 
preparation  of,  233 
Cone,  evolution  of  tooth  forms  from,  17 
Contact,  points  of,  in  teeth,  263 
Contour  fillings,  261 
Contouring  apparatus.  Case's,  821,  833 
Contraction  of  amalgams,  307 
Controllers  for  cataphoresis,  199,  202 
Copper  amalgam,  process  of  making,  312 

staining  of  teeth  by,  558 
Corundum  wheels,   use  of,  in  regulating, 

736 
Cotton  as  a  canal  filling,  464 

as  a  root  filling,  437 

as  a  separator,  186 

method  of  introduction  into  root  canals, 
465 
Counter-irritation  in  pulp  exposure,  410 
Crown,  restoration  of,  with  amalgam,  324 

structure,  conservation  of,  in  root  filling, 
458 
Crowns,  artificial,  on  natural  roots,  655 
Crver's  studies  of  the  maxillary  sinus,  501 
Crystal  gold,  273 

mat  gold,  274 
Cunningham's  regulating  method,  800 
Cusp,  supplementary,  on  first  molar,  227 


Cusps,  malocclusion  of,  788 
Custer's  annealing  tray,  275 
Cutter's  regulating  appliance. 


792 


DAVENPORT'S   regulating  appliance, 
793 
Decay,  removal  of,  in  preparation  of  cavi- 
ties, 217 
Deciduous  teeth,  indications  for  extraction, 
of,  561,  689 
macroscopic  anatomy  of,  48 
management  of,  663 
Deformities,  inheritance  of,  805 
Dental  arch,  tvpal  forms  of,  18 
follicle,  71 
formula  of  man,  22 
groove,  55 
pulp,  capping  of,  411 

conservative  treatment  of,  401 
devitalization  of,  421 
embryology  of,  87 
exposure  of,  403 
sensitivity  of,  402 
ridge,  formation  of,  55 
sacculus,  41 

tissue,  structure  of,  53,  96 
Dentate  fissure  burs,  452 
Dentin,  analysis  of,  121 
calcification  of,  74 
carious,   removal   of,  in   preparation  of 

cavities,  218 
discoloration  of,  425 
germ,  formation  of,  60 
hypersensitive,  189 
treatment  of,  193 
infection  of,  457 
matrix,  77,  121 
normal  sensitivity  of,  190 
secondary,  414,  417 
structural  elements  of,  120 
Dentinal   anesthesia   bv   chemical   agents,. 
207 
papilla,  embryology  of,  70 
tubuli,  fibrillar  structure  of,  192 
Dentition,  pathological,  663 
Development  of  dental  tissues,  53 

of  jaws,  53,  94 
Devitalizing  fiber,  679 
paste,  421,  423,  678 
Diet,  relation  of,  to  pyorrhea,  527 
Dietetic  treatment  of  pyorrhea,  530 
Digitalis  as  a  hemostatic,  617 
Dioxid  bleaching  methods,  550 
Disinfectants  in  pulp  treatment,  433 
Dissection,  necessitv  for,  576 
Distal  cavities,  filling  of,  287,  294 
occlusion  of,  685 
preparation  of,  229,  231 
Disto-incisal  cavities,  filling  of,  288 
Disto-labial  cavities,  filling"  of,  287 

preparation  of,  233 
Disto-lingnal  cavities,  filling  of,  288 

preparation  of,  233 
Disto-occlusal  cavities,  filling  of,  290 

preparation  of,  237 
Donaldson's  pulp-canal  cleaners,  454 
Drag-screw,  use  of,  in  regulating,  749 


846 


INDEX. 


Drill,  safety,  for  pulp  extraction,  455 
Dyiianu),  use  of,  fur  eatai^horesis,  203 
Dyspepsia  due  to  irre^-ularities,  700 

EBUKNATION,  VM 
Edge,  restoration  of,  with  gold,  286 
Edge  strength  of  amalgams,  258 

of  tillings,  845 
Eleetric  mouth-lamp,  176,  177 
Electrical  osmosis,  194 
Electricity,  cataphoric  action  of,  194 

general  principles  of,  196 
Electrodes  for  cataphoresis,  26G 
Electro-magnetic  mallet,  279 
Electrozone,  434 
Elevators,  574 

for  tooth  extraction,  543 

non-use  of,  under  anesthesia,  635 
Emhryology  of  dental  tissues,  53 
Embryonic  mucous  membrane,  54 
Enamel,  analysis  of,  98 

calcitlcation  of,  82 

cleavage  of,  221 

"  drops,"  84 

injury  to,  by  regulating  appliances,  702 

organ,  formation  of,  60,  62 

structural  elements  of,  96 
Engine  burs,  use  of,  in  opening  cavities, 
215 
on  children's  teeth,  676 
Eroded  areas,  304 

Essential  oils  as  antiseptics,  434,  436 
Ether,  administration  of,  for  anesthesia,  212 

mode  of  administration,  619 

use  of,  in  tooth  extraction,  618 
Ethyl  chlorid  as  a  local  anesthetic,  639 
Eucain  as  a  local  anesthetic,  644 
Examinations,  appliances  used  in,  174 

record  of,  178 

technique  of,  177 
Excavators,  forms  of,  218,  232 
Explorers,  use  of,  in  examinations,  175 
Expression,  features  of,  659 
Extracting,  art  of,  635 
Extraction,  after-treatment  of,  611,  637 

mode  of,  under  anesthesia,  634 

FACE,  esthetic  development  of,  824 
measurements  of,  683 
Face-piece,  use  of,  in  nitrous  oxid  adminis- 
tration, 631 
Facial  contour,  influence  of  the  teeth  on, 
805 
deformities,  correction  of,  812 
expression,  change  of,  by  movement  of 

teeth,  809 
profile,  ideal,  683 
Facing  amalgam,  323 
Faught's  electric  heater,  for  gutta-percha, 

329 
Felt  tin,  296 
Fibers  of  Tomes,  127 
Filling  materials  for  deciduous  teeth,  669 
amalgam,  675 

laclv  of  edge  strengtt,  345 
gutta-percha,  669 
selection  of,  249,  267 


Filling  materials,  table  showing  character- 
istics, 370 
zinc  phosphate  cement.  672 
Fillings,  amalgam  and  gold,  354 

amalgams  of  ditlerent  quality,  367 

cement,  amalgam,  and  gold,  358 
and  alloy,  367 
and  amalgam,  351 
and  gold,  353 

combination,  345 

crvstal  mat  and  other  forms  of  gold,  361 

finishing  of,  297,  325,  335 

gold  and  tin,  865 

gutta-percha  and  amalgam,  361 
and  cement,  359 
and  gold,  861 

non-cohesive  and  cohesive  gold,  363 

removal  of,  preparatory  to  bleaching,  546 

repair  of,  301 

temporarv,  213 

tin  and  gold,  367 

tin-gold,  365 

zinc  phosphate  and  amalgam,  346 
Finishing  bur  for  cavity  margins,  222 
Firth's  method  of  pulp  mummification,  441 
Fistula,  treatment  of,  497 
Fistulic  of  alveolar  abscess,  482 
Fistulous  abscess,  treatment  of,  492 
Flagg's  formula  for  amalgam,  313 

gutta-percha  softener,  328 
Fletcher's  carbolized  resin,  667,  674 

method  of  mixing  amalgams,  319 
Floss  silk,  use  of,  in  deciduous  teeth,  681 

in  examinations,  179 
"Flow"  of  amalgams,  308 
Force,  application  of,  in  filling  operations, 
276 

constant,  706 

intermittent,  706 
Forceps,  antiseptic,  564 

best  forms  of,  564 

extracting,  manner  of  use,  597 

for  extracting  lower  teeth,  572 

forms  of,  for  regulating,  799 

knuckle-joint,  566 

necessary  forms  of,  635 

nickel-plating  of,  636 

pharyngeal,  use  of,  577 
Formalin  as  an  antiseptic,  469,  471 

in  pulp  treatment,  422,  485 
Furnaces  for  fusing  porcelain,  393 

GALVANIC  current,  application  of,  to 
sensitive  dentin,  200 
Gangrenous  pulps,  micro-organisms  in,  430 
Gauge,  plate,  704 
German-silver  matrix,  349 
Germicides  in  pulp  treatment,  483 
Gilded  platinum,  358 

Gilling  twine,  use  of,  in  polishing  teeth,  182 
Gingivitis  expulsiva,  505,  509 
Glands  of  Serres,  90 

Glossitis  resulting  from  alveolar  abscess, 501 
Gold,  amalgamation  of,  in  combination  till- 
ings, 357 

and  amalgam  tillings,  354 

and  cement  tillings,  353 


INDEX. 


847 


Gold,  and  platinum,  274 

and  tin  lillings,  365 

annealini];  of,  274 

as  a  canal  tilling,  463,  467 

as  a  tilling  material,  250,  267 

as  a  root  tilling,  437 

cohesive,  271 

combination  fillings  of,  361 

ciystal,  273 
mat,  274 
.  device  for  rolling,  270 

inlays,  396 

non-cohesive,  268 
and  cohesive,  363 

overlapping  of,  in  finishing  fillings,  299 

packing  of,  275 

plastic,  granular  qualities  of,  367 

plating,  removal  of,  from  steel,  865 

staining  of  teeth  by,  558 

use  of,  in  children's  teeth,  677 
Gout,  articular,  521 

nervous,  521 

tegumentary,  521 

visceral,  521 
Gouty  diathesis,  519 

pericementitis,  509,  515 

theory  of  pyorrhea,  508,  518 
Granular  layer  of  Tomes,  125 
Grooves,  formation  of,  in  shaping  cavities, 

221 
Gubernaculum,  72 
Gum,  hypersensitiveness  of,  188 

incision  of,  for  implantation  of  teeth,  658 

inflammatory  disturbance  of,  183 

lancing,  indications  for,  664 

protection  of,  in  preparation  of  cavities, 
228 

scarification  of,  in  pulp  exposure,  416 

tissue,  embryology  of,  90 

treatment  of,  after  extraction,  613 
Gutta-percha  and  amalgam  fillings,  361 

and  cemi^nt  fillings,  359 

and  gold  fillings,  361 

as  a  canal  filling,  463 

as  a  root  filling,  438 

as  a  separator,  187 

as  a  temporary  filling,  214 

canal  filling  in  bleaching  operations,  545 

classes  of,  326 

expansion  of,  361 

fillings,  finishing  of,  334 

first  use  of,  as  a  filling  material,  326 

heating  of,  360 

indications  for  employment,  327 

manipulation  of,  329 

physical  properties,  327 

use  of,  in  deciduous  teeth,  669 

HAKLAiSr-S  bleaching  method,  551 
Harvard  cement  for  setting  inlays,  385 
Heat,  evolution  of,  by  engine  burs,  218 
Hematogenic  calcic  pericementitis,  509 
Hemoglobin,    decomposition    products    of, 

537 
Hemorrhage,  dental,  causes  of,  616 

treatment  of,  after  extraction,  614 
Hemorrhagic  diathesis,  treatment  of,  615 


Hemostatics,  formula  for,  617 
Herbst's  matrices,  317 

method  of  inlaying,  375 

retaining  method.  730 
Heredity  as  a  predisposing  cause  of  pyor- 
rhea, 526 

influence  of,  on  the  teeth,  690 
Hewitts  anesthetic  apparatus,  624 

mouth-props,  577 
Hiirs  stopping,  326 
Hoe  excavators,  232 

Holes,  arrangement  of,  in  rubber  dam,  241 
Hollingsworth's  cataphoric   appliances  for 
bleaching  teeth,  556 

syringe  electrode,  206 
Hot-water  douche  in  bleaching  operations, 

548 
How's  method  of  packing  gutta-percha,  330 

of  reshaping  teeth,  736 
Hydrogen  dioxid  as  a  bleaching  agent,  550 

in  pulp  treatment,  460 
Hydronaphthol,  use  of,  in  pyorrhea,  515 
Hygienic  measures  in  pyorrhea,  529 
Hypei-sensitive  dentin,  189 
Hypnosis,  657 

I:\mEDIATE    root   filling,    indications 
for,  431 

wedging,  185 
Implantation,  first  recorded  operation,  646 

instruments  for,  659 

mode  of  operation,  658 

precautions  for,  654 
Impression  trays  for  regulating,  710,  711 
Incisal  cavities,  filling  of,  285 

preparation  of,  229 
Incisions  for  gum-lancing,  665 
Incisor,  central,  extraction  of,  602 
Incisors,  crowded,  744 

deciduous,  filling  of,  675 

lateral,  extraction  of,  602 

macroscopical  anatomy  of,  22 

pulp  chambers  of,  446 

rotation  of,  724 
Infection  through  instruments,  163 
Infectioso-alveolitis,  509 
Infectious  alveolitis,  507 
Inflammation,  treatment  of,  in  root-tilling, 

474 
Inhaler,  Allis's,  213 

for  nitrous  oxid  administration,  630 
Inlays,  amalgam,  371 

antiquity  of,  369 

compared  with  other  fillings,  869 

gold,  379,  396 

hard-rubber,  399 

porcelain,  374 
Instruments,  comfortable  use  of,  173 

disinfection  of,  424 

for  packing  gutta-percha,  329 

for  pulp-canal  treatment,  452 

selection  of,  276 

for  tooth  extraction,  595 
Intermaxillary  bone,  non-development  of, 

787 
Interproximal  space  as  a  predisposing  cause 
of  caries,  177 


848 


INDEX. 


Interproximal  spaces,  polishing  of,  182 
lodin,    c'lujinioal   action   of,    on  hydrogen 
sullid,  471 

trichlorid  as  an  antiseptic,  434 
Iodoform  as  a  germicide,  435 

gauze  as  a  styptic,  614 

in  pulp  devitalization,  422 

paste,  678 
lodol  as  astorilizor,  435 
Iron,  staining  of  teeth  by,  558 

sulfid  as  a  fa(;tor  in  tooth  discoloration, 
538 
Irregularities,  classification  of,  712 

etiology  of,  690 

treatment  of,  702 

JACK-SCKEW    regulating    appliances, 
703 
Jaws,  development  of,  53 

separation  of,  for  tooth  exti'action,  575 

KALIUM-NATRIUM,  434 
Kingsley's  regulating  plate,  738 
Kirk's  method  of  making  copper  amalgam, 

313 
Kristaline,  343,  549 
as  a  cavity  lining,  258 

LABARRAQUE'S  solution,  434 
as  a  bleaching  agent,  549 
Labial  cavities,  filling  of,  284 

preparation  of,  227 
Lancets,  forms  of,  575 

use  of,  in  tooth  extraction,  597,  599 
Lateral  walls  of  cavities,  lining  of,  258 
Laterals,  depressed,  745 

extraction  of,  for  regulating,  745 
Lead  as  a  filling  material,  267 
Leclanche  battery  for  cataphoresis,  202 
Leeches,  application  of,  to  gum,  474 
Lenses,  magnifying,  for  examinations,  177 
Ligatures,  adjustment  of,  350 
in  bleaching  operations,  545 
placing  of,  244 
varnishing,  349 
Light,   management  of,   in  examinations, 

174 
Lingual  cavities,  filling  of,  284,  285 
occlusion,  686 
preparation  of,  227,  228 
Lining  varnishes,  343 
Lithium  compounds,  use  of,  in  pvorrhea, 

530 
Loop  matrices,  290 
Lotion  for  alveolar  abscess,  494 
Lugol's  solution,  502 
Lysol  in  pulp  treatment,  473,  474 

MCQUILLEN'S  bleaching  method,  551 
Magnifying  lenses,  175 
Mallets,  first  introduction  of,  279 

forms  of,  278 
Malocclusion,  685 

as  a  cause  of  pyorrhea,  528 
Malpighian  layer,  54 
Manganese  stains  of  teeth,  559 
Marginal  cavity  lining,  258 


Mass  method  of  tilling  with  gutta-percha, 

331 
Massage  of  the  gums,  184 

in  pericementitis,  476 
Matrices,  improvised,  316 
use  of,  290 

in  combination  fillings,  347 
Matrix,  adjustment  of,  to  tooth,  348 
Matteson's  regulating  appliances,  704,  714 
Maxilla,  lower,  excessive  development  of, 

773 
Maxilhe,  embryology  of,  53 

separation  of,  by  regulating  appliances, 
698 
Maxillary  rampart,  55 

sinus,    opening  of,    into   nasal    passage, 
501 
relation  of  tooth  roots  to,  583 
Mechanical  mallet,  280 
Meckel's  cartilage,  54 
Medicaments,  cataphoric  diffusion  of,  195 
Meditrina,  434 

in  pulp  treatment,  473 
Membrana  eboris,  70,  74,  127 
Membrana  praeformativa,  85 
Mercurv,  percentage  of,  in  amalgams,  253, 
'  307 
staining  of  teeth  by,  559 
Mesial  cavities,  filling  of,  287,  294 
occlusion,  686 
preparation  of,  234 
Mesio-disto-incisal  cavities,  filling  of,  288 

preparation  of,  234 
Mesio-disto-occlusal    cavities,     preparation 

of,  238 
Mesio-incisal  cavities,  filling  of,  288 
Mesio-labial  cavities,  filling  of,  287 

preparation  of,  233 
Mesio-lingual  cavittes,  filling  of,  288 

preparation  of,  333 
Mesio-occlusal  cavities,  filling  of,  289 

preparation  of,  235 
Metal   fillings,    effect  of   temperature   on, 
352 
pulp  disturbance  from,  419 
Metallic  fillings,  insulation  of,  in  catapho- 
resis, 203 
salts,  staining  of  teeth  by,  537 
stains,  tooth  discoloration  by,  543 
Metals,  action  of  chlorin  on,  547 
as  canal  fillings,  437 
modification  of  alloys  by,  314 
Methyl  chlorid  as  a  local  anesthetic,  639 
Micro-organisms,   invasion    of  pulp  tissue 

by,  429 
Microscopic  "specimens,  preparation  of,  76 
Miller  matrices,  317 

Miller's  experiments  on  pulp  mummifica- 
tion, 340 
Mineral  acids,    action  of,    on  dental  pulp, 

434,  436 
Mixing  tablet,  339 
Modelling     compound    as    an    impression 

material,  710 
Moisture,  avoidance  of,  in  preparation  of 

cavities,  219,  239,  347 
Molar,  impacted,  extraction  of,  609,  636 


INDEX. 


849 


Molars,  extraction  of,  603,  607,  608 

first,  early  extraction  of,  562 

microscopical  anatomy  of,  37 

pulp  chambers  of,  448,  449,  450,  451 

supernumerary,  48 

temporary,  preservation  of,  667 
Monsel's  solution  as  a  styptic,  614 
Morphia,  treatment  of  sensitive  dentin  by, 

193 
Mortars  for  mixing  amalgam,  318 
Mouth,  hygiene  of,  182 

mirror,  use  of,  175 

opener,  mechanical,  576 

preliminary  examination  of,  173 

preparation  of,  for  local  anesthesia,  643 
Mouth-breathing,  irregularities  caused  by, 

566 
Mouth-props  in  tooth  extraction,  575,  631 
Mouth-wash,  antiseptic,  514 

formula  for,  183 
Mucous  surfaces,  treatment  of,  jircliminary 

to  operation,  183 
Muffles  for  baking  porcelain,  393 
Mummification  of  the  dental  pulp,  439 
Mummifying  paste,  441,  446 

NAPKIXS,  use  of,  in  filling  operations, 
246 
Narcosis,  symptoms  of,  633 
Nasal  floor,  perforation  of,  bv  alveolar  ab- 
scess, 483 
Nasmyth's  membrane,  92 
Nausea,  relief  of,  in  filling  operations,  247 
Necrosis  from  alveolar  abscess,  486 
Nerve  instruments,  455 
Nervous  gout,  521 
•'  New-departure  corps,"  306 
Nickel,  staining  of  teeth  by,  558 
Nitrate  of  silver  as  an  anesthetic,  212 
Nitric  acid  as  an  anesthetic,  212 
Nitrous  oxid, advantages  of, as  an  anesthetic, 
629 

combination  of,  with  oxygen,  624 

in  tooth  extraction,  620,^629 

inhaler  for,  630 

mode  of  administration,  632 

mouthpieces  for,  622 

portable  apparatus,  624 
Nostrums,  anesthetic,  dangers  of,  642 

OBTUNDING  the  pulp,  pressure  method 
of,  425 
Occlusal  cavities,  filling  of,  282 

preparation  of,  224 
Occlusion,  anterior,  lack  of,  786 
distal,  685 
line  of.  19 
lingual,  681 
mal-,  685 
mesial,  686 
normal,  579 
Occluso-buccal  cavities,  filling  of,  294 

preparation  of,  237 
Occluso-lingual  cavities,  filling  of,  294 

preparation  of,  238 
Occupatifin,  relation  of,  to  pyorrhea,  527 
Odontalgia,  treatment  of,  in  children,  666 
54 


Odontoblasts,  76,  127 

Oil  of  cinnamon  as  a  sterilizer,  441 

pad,  substitute  for,  360 
Oils,  essential,  as  antiseptics,  434,  436 
Operator,  position  of,  at  the  chair,  173 
Oral  fluids,  effect  of  acid  conditions  of,  191 
Orthopedia.  facial,  808 
Osmosis,  influence  of  electrical  current  on, 

194 
Osteoblasts,  146 
Osteoclasts,  148 

development  of,  on  dental  pulp,  421 
Osteo-periostiti-alveolo-dentaire,  505,  509 
'•  Out-and-in  ''  motion  in  tooth  extraction, 

585,  600 
Overbite,  excessive,  790 
Oxidizing  bleachers,  540 
Oxychlorid  of  zinc  as  a  filling    material. 
255,  334 
as  a  permanent  filling,  548 
Oxygen  as  a  sterilizer,  434 

combination  of,  with  nitrous  oxid,  624 
Oxysulfate  of  zinc,  343 
Ozena,  alveolar  abscess  mistaken  for,  483, 
487 

PACKING  of  amalgam,  319 
Pain,  diagnosis  of,  in  children,  667 
Pain  reflected  from  exposed  pulps,  416 
Palladium  amalgam,  313 
ParatRn  as  a  canal  filling,  464,  467 
as  a  root  filling,  439 
coating  for  cement,  675 
Patients,  instructions  to,  182 
management  of,  594 

phvsical  examination  of,  before  anesthe- 
sia, 618 
position  of,  in  tooth  extraction.  594 
Pepper  plasters,  use  of,  in  abscess,  492 
Pericementitis,  chronic,  treatment  of,  476 
gouty,  515 
treatment  of,  473 
Pericementum,  embryology  of,  91 
involvement  of,  in  pyorrhea,  522 
preservation  of,  in  implanting  teeth,  652 
revivification  of,  651 
rupture  of.    from  regulating  appliances. 

701 
septic  infection  of,  457 
Peridental  membrane,  structural  elements 

of,  91,  135 
Permanent  teeth,  indications  for  extraction 

of,  561 
Phagedenic  pericementitis,  509 

alveolar  abscess  associated  with.  494 
Phosphoric  acid,  impurities  of.  337 
Phvsiognomv,    relations  of,   to  the  teeth, 

805.  823 
Piano-wire  regulating  appliances,  703 
Pink  base  plate  as  a  temporary  filling.  327 
Plane,  inclined,  for  regulating.  714 
Plastic  gold,  combination  of,  with  cement, 
353 
golds,  361 
root  fillings.  437 
Plastics  as  filling  materials,  305 
Plate,  regulating,  713,  721 


850 


INDEX. 


Platinum  ani)de  fur  oataphoresis,  205 

matrix  tor  inlay  work,  379 
Pliers,  ri!gulatin<^,  727 
Plugging   instruments,  selection    of,   276, 

282 
Porcelain  cavity  stoppers,  374 
inlays,  374 
baking  of,  393 
furnaces  for  baking,  393 
gold  matrices  for,  376,  388 
high-fusing     and      low-fusing      tooth 

bodies  for,  375,  393 
insertion  of,  384 

making  matrices  upon  models  for,  400 
matching  colcjrs  for,  386 
platinum  matrices  for,  376,  379 
preparation  of  cavity  for,  377 
setting  of,  385 
Position  at  the  dental  chair,  175 
Potassium  carbonate,  use  of,  in  pyorrhea, 

530 
Poultices,  use  of,  in  alveolar  abscess,  494 
Pressure  method  of  obtunding  the  pulp,  425 
Profiles,  study  of,  810 
Prognathism,  822 
Protrusions,  lower  dental,  773 

upper  dental,  811 
Ptyalogenic  calcic  pericementitis,  510 
Pulp,  calcific  changes  in,  417 
canals,  abnormalities  of,  451 
cleansing  of,  456 
enlargement  of,  457 
filling  of,  in  bleaching  operations,  545 
septic,  treatment  of,  469 
sterilization  of,  491 
treatment  of,  in  deciduous  teeth,  679 
capping,  411 
chambers,     topographical    anatomy    of, 

446 
death   of,    from    regulating    appliances, 

701 
devitalization,  421 
discoloration  of  tooth  from  death  of,  536, 

539 
exposure  in  deciduous  teeth,  677 
phenomena  of,  405 
treatment  of,  409 
functions  of,  131 
mummification  of,  429,  439 
nodules,  419 

obtunding  of,  pressure  method,  425 
reaction  of,  diagnostic  value  of  thermal 

tests  to,  406 
stones,  420 

structural  elements  of,  127 
Pulps,  mummified,  in  root  canals,  468 
Pumice,  use  of,  in  polishing  teeth,  181 
Punch,  rubber  dam,  241 
Pus,  burrowing  of,  in  alveolar  abscess,  483, 
487 
evacuation  of,  in   alveolar  abscess,  490, 

494 
formation,  results  of,  on  tooth  roots,  496 
Putrefactive  decomposition,  process  of,  538 
Pyorrhea  alveolaris,  causation  of,  526 
classification  of,  510 
diagnosis  of,  525 


Pyorrhea    alveolaris,    gingival    origin    of, 
506 
history  of,  505 
pathology  of,  519 
recurrence  of,  531 
terminology  of,  509 
treatment  of,  528 
alveolo,  509 
complex,  532 

inter-alveolo-dentaire,  485,  509 
simplex,  532 
Pyrozone  as  a  bleaching  agent,  551 
use  of,  in  alveolar  abscess,  498 
in  root  tilling,  469 

/QUATERNARY  amalgams,  314 

REAMERS,  implantation,  555 
use  of,  in  pulp  canals,  455,  456,  461 
Records,  preservation  of,  4l6 
Regulating  appliances : 

Angle's,   703,  710,   711,  727,  728,  742, 

752,  759,  769,  775,  776 
Case's,  791,  793,  834 
Cotfin's,  707,  708 
Farrar's,  795 
Goddard's,  717,  719,  729,  730,  731,  732, 

767,  792 
Guilford's,  747,  751,  765 
Jackson's,  715,  752,  766 
Kingsley's,  738,  759,  789 
Magill's,  703 
Matteson's,  704,  714,  729 
Talbot's,  716,  722 
general  directions  for,  708 
surgical  methods  in,  802 
Replantation  in  alveohir  abscess,  499 
Resin,  carbolized,  667,  675 
Resistance,  table  of,  200 
Restoration  of  teeth  by  cemented  inlays, 

369 
Retaining  appliances,  contact  of,  702 
grooves  in  approximal  cavities,  230,  231, 

236 
plugs,  743 
Retention  caps  for  planted  teeth,  652 
Retrusions,  upper  dental,  817 
Retzius,  brown  bands  of,  107 
Rhein's  method  of  packing  amalgam,  322 
Rheostats  for  cataphoresis,  199 
Riggs'  disease,  509 
Robinson's  remedy,  207 
Root  canal  fillings,  463 

canals,  treatment  and  filling  of,  429 
filling  in  bleaching  operations,  545 
Roots,  anomalous,  450 
artificial,  653 
broken,  removal  of,  612 
depression  of,  by  regulating  appliances, 

701 
extraction  of,  574 
movement  f>f,  795 
perforation  of,  503 
relation  of,  to  maxillary  sinus,  583 
resorption  of,  in  planted  teeth,  661 
Royal  mineral  succedaneum,  305 


INDEX. 


851 


Rubber  band  for  regulatinej,  702,  706,  720, 
733 
cup  for  emptying  abscess  cavities,  493 
dam,  adjustment  of,  352 

for  bleaching  operations,  5-44 
application  of,  in  children,  673 
clamps.  244,  285 

application  of,  245 
holders,  245 

mode  of  application,  243 
punch,  241 
shields,  247 

use  of,  in  tilling  operations,  239 
as  a  separator,  187 

SALINE  waters,  use  of,  in  pyorrhea,  529 
Saliva,  control  of,  in  filling  operations, 
239 
Salivary  calculus,  formation  of,  from  irreg- 
ularities, 701 
removal  of.  181 
Salol  as  a  canal  filling.  404.  467 
and  gutta-percha  canal  filling,  492 
as  a  root  filling,  439 
use  of,  in  deciduous  teeth,  680 
Sandarac  varnish,  343 
Sanguinarv  calculus,  507 
Scalers.  Abbotts,  182 
Cushings,  512 
for  root  extraction.  573 
Schleich's  cocain  solution,  642 
Schreier's  preparation  in  tooth-bleaching, 

551 
Scissors,  gum,  576 
Screw  matrices,  292 
Secondary  dentin,  414,  417 
Self-cleansing  spaces,  262 
Sensitivity,  zone  of,  in  dental  caries,  191 
Separations,  methods  of  making,  185 
Separators,  forms  of.  186 
Septic  infection  of  the  dental  pulp,  432 
Sex,  relation  of,  to  pyorrhea,  527 
Sharpey's  fibers,  87 
Sheaths  of  Neumann,  121 
Shredded  tin,  use  of,  in  root-filling,  467 
Silver  nitrate,  use  of,  in   deciduous  teeth, 
667 
paste.  305 
Silver-tin  allovs.  tables  of  results  from  an- 
nealing, 309,  310 
Simple  approximal  cavities,  preparation  of, 
229 
cavities,  filling  of,  282 
preparation  of,  224 
Skiagraph,  diagnostic  uses  of,  592 
Soderberg's   method  of  pulp   mummifica- 
tion, 441 
Sodium  dioxid  as  a  bleaching  agent,  552 

use  of,  in  septic  pulp  canals,  471 
Soft  gold,  363 

and  heavy  gold,  combination  of,  364 
Space,  retention  of,  in  separations,  187 
Spheroiding  of  amalgams,  308 
Splints,  metallic,  for  pyorrhea,  512 
Spring  device  for  regulating,  722 
Stains,  special  bleacJBing  methods  for,  558 
Stellate  reticulum  of  enamel  organ,  64 


Sterilization  of  exposed  pulps,  409 

of  instruments  by  boiling  in  soda  solu- 
tinn,  169 
formaldehyd  lamp  for,  168 
formalin  as  an  agent  for,  167 
results  of  tests  of  various  agents  for, 
165 
Storage  batteries,  use  of,  for  cataphoresis, 

202 
Stratum  intermedium,  63 

Malpighii,  54 
Styptics  for  control  of  hemorrhage,  615 
Sulfuric  acid  in  root  canals,  456,  461 
as  a  sterilizer,  434 
ether,    advantages  of,   as  an  anesthetic, 
212 
method  of  application,  212 
Sulfurous  acid  as  a  bleaching  agent,  554 
Suppuration  conjoint,  509 
Symbols,  examination,  179 
Syringes  for  pulp-canal  treatment,  453 
warm-air,  208 

TALBOT'S   regulating   appliances.    716, 
722 
Tampon  for  controlling  hemorrhage,  614 
Tannic  acid  in  pulp  exposure,  679 
in  pulp  treatment,  422 
use  of,  in  hemorrhage,  614 
Tap  openings  for  pulp  treatment,  459 
Tape  as  a  separator,  186 
Tartarlithine.  lithium  bitartrate,  530 
Taylor's  regulating  appliance,  751 
Teeth,  abnormalities  in,  593 

accidents  to,  during  extraction,  612 
anchorage  of,  in  regulating,  715 
bleaching  of,  540 
Carabelli"s  sectional  views  of,  442 
cleansing  of,  181 
crowded,  extraction  of,  613 
deciduous,  alveolar  abscess  in,  680 
duration  of,  665 
eruption  of.  663 
extraction  of,  595,  600 
filling  of,  609 

macroscopic  anatomy  of,  48 
prophylactic  treatment  of,  681 
pulp  treatment  of,  677 
rules  against  extraction  of,  691 
discoloration  of,  535 
by  amalgam,  358 
embryology  of,  53 
examination  of,  preliminarv  to  operation, 

173 
exfoliation  of,  in  pyorrhea,  518 
extraction  of.  561 
for  regulating,  746 
under  anesthesia,  634 
extrusion  of,  729 
forces  used  in  moving,  708 
histologv  of,  with  reference  to  operative 

"'dentistry,  93 
immediate  movement  of,  799 
indications  for  extraction  of,  561 
influence  of,  on  the  phvsiognomv,   805, 

823 
instruments  for  extraction  of,  564 


852 


INDEX. 


Tcoth,  irregularities  of,  690 
lahiul  displacement  of,  720 
liiit;iuil  tlisplnconient  of,  712 
li>\VLT,  lixtraction  of,  GU(i 
macroscopic  anatomy  of,  17 
movement  of,  in  regulating,  709,  718 
normal  forms  of,  5!t2 

occlusion  of,  19,  084 
oral,  combination  fillings  for,  353,  355 

extraction  of,  (iOH 
partial  eruption  of,  731 
parts  of,  most  liable  to  caries,  177 
permanent,  order  of  eruption,  688 
plantation  of,  645 
planted,  life  of,  654 

mode  of  attachment,  653 
subsequent  care  of,  652 
pulp  chambers  of,  446 
relation  of,  to  temperament,  51 
removal  of,  for  artificial  dentures,  563 
replantation  of,  648 

in  alveolar  abscess,  499 
reshaping  of,  736 
retention  of,  after  regulating,  742 
rotation  of,  724 

in  extracting,  600 
scaling  of,  in  pyorrhea,  512 
separation  of,  185,  243 
surgical  anatomy  of,  577 
temporary,  abscess  on,  .502 
combination  filling  for,  359 
indications  for  extraction  of,  561 
management  of,  663 
temperature  sense  of,  402 
transplantation  of,  650 
upper,  protrusion,  760,  773 
Tegumentary  gout,  521 
Temperament,  relation  of  teeth  to,  51 
Temperamental   indications  for  pulp  treat- 
ment, 415 
Temperature  sense  of  teeth,  402 
Temporary  stopping,  342,  438 
Ternary  amalgams,  313 
Therapeutic  treatment  of  sensitive  dentin, 

193 
Therapeutics  of  pulp  treatment,  433 
Thermoscopic  heater,  331 
Thumb-sucking,  irregularities   caused   by, 
696" 
relation  of,  to  protruding  teeth,  761 
Tin,  as  a  canal  filling,  463 
as  a  cavity  lining,  258 
as  a  filling  material,  251,  267,  295 
cohesive  propertv  of,  296 
felt,  296 

instruments  for  filling  with,  296 
shavings  of,  296 
shredded,  296 

thermal  conductivity  of,  251 
use  of,  in  children's  teeth,  677 
Tin-gold,  365 


Tin  and  gold,  367 

Tissues,  changes  of,  by  movement  of  teeth, 
697 

Tomes,  fibers  of,  127 
granular  layer  of,  125 

Tonics,  general,  61(j 

Tonsils,  enlarged,  irregularities  caused  by, 
697 

Tooth  develojimeiit,  chronology  of,  88 
extraction,  general  jirinciples  in,  593 
forms,  evolution  of,  17 

variations  of,  50 
molar,  impaction  of,  589 
prejjaration  of,  for  bleaching,  543 
structure,  discoloration  of.  by  amalgam, 
311 
saving  of,  by  combination  filling,  356 

Toothache,  treatment  of,  in  children,  666 

Tooth-l)rush,  correct  use  of,  182 

Townsend's  alloy,  313 

Transillumination  of  the  teeth,  177 

Transmission  of  oral  diseases,  160 

Trichloracetic  acid,  use  of,  in  pyorrhea,  512 

Tropacocain  as  a  local  anesthetic,  642 

Truman's  bleaching  method,  546 

Tuberculate  teeth,  37 

Tutt's  powder,  182 

URATES,  accumulation  of,  in  the  blood, 
521 
Uric  acid  theory  of  pyorrhea,  508 

VARNISHING  fillings,  333 
Velvet  gold  cylinders,  289 
Veratria,  treatment  of  sensitive  dentin  by, 

193 
Visceral  gout,  521 
Vulnerable  point  of  cavities,  235 

WAFERING  of  amalgams,  320 
Warmed  air  as  an  anesthetic,  207 
Wedges  for  regulating,  718 
as  separators,  185 
use  of,  in  examinations,  177 
Weston's  method  of  mixing  cements,  339 
Willms  controller  for  cataphoresis,  202 
Wright's  bleaching  method,  549 

ZINC  chlorid  as  an  anesthetic,  209 
use  of,  in  root  canals,  462 
oxychlorid  as  a  canal  filling,  463 
as  a  root  filling,  437 
formula  of  manufacture,  336 
use  of,  in  dentistry,  386 
oxysull'ate  as  a  pulji  capping,  343 
phosphate  as  a  cavity  lining,  259 

as  a  filling  material,  256,  267,  338,  346, 

672 
cements,  336 
making  of  powder,  336 
mixing  of,  339 


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